5-Aminolevulinic acid-based photodynamic therapy

2282

5-Aminolevulinic Acid–Based Photodynamic TherapyClinical Research and Future Challenges

BACKGROUND. Photodynamic therapy (PDT) for cancer patients has developed intoQian Peng, M.D., Ph.D.1,3

an important new clinical treatment modality in the past 25 years. PDT involvesTrond Warloe, M.D., Ph.D.2

administration of a tumor-localizing photosensitizer or photosensitizer prodrugKristian Berg, Ph.D.3

(5-aminolevulinic acid [ALA], a precursor in the heme biosynthetic pathway) andJohan Moan, Ph.D.3

the subsequent activation of the photosensitizer by light. Although several photo-Magne Kongshaug, Ph.D.3

sensitizers other than ALA-derived protoporphyrin IX (PpIX) have been used inKarl-Erik Giercksky, M.D., Ph.D.2

clinical PDT, ALA-based PDT has been the most active area of clinical PDT researchJahn M. Nesland, M.D., Ph.D.1

during the past 5 years. Studies have shown that a higher accumulation of ALA-

derived PpIX in rapidly proliferating cells may provide a biologic rationale for1 Department of Pathology, The Norwegian Ra-

clinical use of ALA-based PDT and diagnosis. However, no review updating thedium Hospital, University of Oslo, Oslo, Norway.clinical data has appeared so far.

2 Department of Surgical Oncology, The Norwe- METHODS. A review of recently published data on clinical ALA-based PDT andgian Radium Hospital, University of Oslo, Oslo, diagnosis was conducted.Norway. RESULTS. Several individual studies in which patients with primary nonmelanoma

cutaneous tumors received topical ALA-based PDT have reported promising re-3 Department of Biophysics, Institute for CancerResearch, The Norwegian Radium Hospital, sults, including outstanding cosmetic results. However, the modality with presentUniversity of Oslo, Oslo, Norway. protocols does not, in general, appear to be superior to conventional therapies

with respect to initial complete response rates and long term recurrence rates,

particularly in the treatment of nodular skin tumors. Topical ALA-PDT does have

the following advantages over conventional treatments: it is noninvasive; it pro-

duces excellent cosmetic results; it is well tolerated by patients; it can be used to

treat multiple superficial lesions in short treatment sessions; it can be applied to

patients who refuse surgery or have pacemakers and bleeding tendency; it can be

used to treat lesions in specific locations, such as the oral mucosa or the genital

area; it can be used as a palliative treatment; and it can be applied repeatedly

without cumulative toxicity. Topical ALA-PDT also has potential as a treatment

for nonneoplastic skin diseases. Systemic administration of ALA does not seem to

be severely toxic, but the advantage of using this approach for PDT of superficial

lesions of internal hollow organs is still uncertain. The ALA-derived porphyrin

fluorescence technique would be useful in the diagnosis of superficial lesions ofSupported by the Norwegian Cancer Society. internal hollow organs.

CONCLUSIONS. Promising results of ALA-based clinical PDT and diagnosis haveThe authors thank Drs. J. M. Gaullier and G. B. been obtained. The modality has advantages over conventional treatments. How-Kristensen for fruitful cooperation and V. Iani,

ever, some improvements need to be made, such as optimization of parametersH. Heyerdahl, E. Hellesylt, and W. Danielsen forof ALA-based PDT and diagnosis; increased tumor selectivity of ALA-derived PpIX;excellent technical assistance.better understanding of light distribution in tissue; improvement of light dosimetry

procedure; and development of simpler, cheaper, and more efficient light deliveryAddress for reprints: Qian Peng, M.D., Ph.D.,Department of Biophysics, Institute for Cancer systems. Cancer 1997;79:2282–308. q 1997 American Cancer Society.Research, The Norwegian Radium Hospital,

KEYWORDS: 5-aminolevulinic acid, protoporphyrin IX, heme synthesis, light, cancer,University of Oslo, Montebello, N-0310 Oslo,Norway. diagnosis, photodynamic therapy.

IReceived November 1, 1996; revision receivedFebruary 4, 1997; accepted February 4, 1997.

n the first step of the heme biosynthetic pathway, 5-aminolevulinicacid (ALA) is formed from glycine and succinyl coenzyme A (CoA).

q 1997 American Cancer Society

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Clinical ALA-Based Photodynamic Therapy/Peng et al. 2283

The last step is the incorporation of iron into protopor- bacteria, ALA is formed from glycine and succinyl-CoAby the enzyme ALA synthase (ALAS). In vertebrates,phyrin IX (PpIX), which takes place in the mitochon-

dria under the action of the enzyme ferrochelatase. there are two ALAS isoenzymes, a housekeeping ALASand an erythroid specific isoenzyme. The enzyme isWith the addition of exogenous ALA, PpIX may accu-

mulate because of the limited capacity of ferrochela- located on the matrix side of the inner mitochondrialmembrane,38 loosely associated with the membrane.39tase. Porphobilinogen deaminase is another enzyme

of the heme synthesis pathway (catalyzing the forma- The enzyme has the main regulatory function of thepathway.tion of uroporphyrinogen from porphobilinogen). Its

activity is higher in some tumors,1–3 whereas that of The next enzyme in the pathway, ALA dehydra-tase, is located in the cytosol and induces the conden-ferrochelatase is lower,2–8 so that PpIX accumulates

with some degree of selectivity in such tumors. Be- sation of two molecules of ALA to yield porphobilino-gen (PBG) with the elimination of two water molecules.cause PpIX is an efficient photosensitizer, ALA has

been introduced as a drug for clinical photodynamic The combined action of PBG deaminase (PBGD) anduroporphyrinogen III (co)syntase40 condenses in atherapy (PDT) of cancer.9,10 PDT involves, in general,

systemic administration of a tumor-localizing photo- head-to-tail manner four molecules of PBG and cy-clizes the tetrapyrrole chain to form uroporphyrinogensensitizer or photosensitizer prodrug and the subse-

quent activation of the photosensitizer by light. In III. Both enzymes are located in the cytosol, and theaction of PBGD is the rate-limiting step. A series of1990, Kennedy et al.9 first applied topically ALA-based

PDT in a clinical setting. Today ALA-PDT is success- decarboxylations and oxidations have to take placebefore iron can be inserted into the tetrapyrrole ring.fully used for the treatment of a variety of neoplastic

and nonneoplastic diseases. The first part of this process is performed in the cytosolby uroporphyrinogen decarboxylase. This enzyme re-ALA can be applied topically or systemically for PDT

of skin and other tumors (such as skin basal cell carci- moves four acetic acid carboxyl groups from uro-porphyrinogen to form the tetracarboxylic copropor-noma and gastrointestinal adenocarcinoma).9,11–17 It can

also be used for diagnostic evaluations of tumors of the phyrinogen. Coproporphyrinogen III, to be used forheme synthesis, is now exposed to coproporphyrino-skin, bladder, gastrointestinal tract, and lung.16–19 ALA is

hydrophilic and does not easily penetrate through intact gen oxidase, which is situated in the intermembranespace of the mitochondria.41,42 The enzyme decarbox-skin,9,20,21 or through cell membranes.22 When ALA is ap-

plied topically to cutaneous tumors, the tumor selectivity ylates and oxidizes the propionic side chains in ringA and B to vinyl groups, and protoporphyrinogen IXis also caused by an increased permeability of the skin

tumor. Nodular skin tumors with a relatively intact kera- is formed. The final step in the synthesis of PpIX isthe oxidation of the tetrapyrrole ring by removal of sixtinized surface layer are refractive to topical ALA-PDT

because ALA does not penetrate to their base. We have hydrogens from protoporphyrinogen IX, catalyzed byprotoporphyrinogen oxidase. The enzyme is embed-therefore made progress in the field of ALA-based PDT

by studying a number of lipophilic ALA ester derivatives. ded in the inner mitochondrial membrane with itsactive site on the matrix side of the membrane.43 ItThese are more lipophilic and may penetrate more easily

through the keratinized layer and deeper into tumors than is an oxygen-dependent enzyme with high substratespecificity.44 The tetrapyrrole structure is now readyALA itself.23,24 The esterase activity in cells and tissues

leads to cleavage of ALA from the ALA ester derivatives. for the incorporation of iron, which is catalyzed byferrochelatase (EC 4.99.1.1). Ferrochelatase is locatedALA-based PDT has been the most active area of

PDT research during the past 5 years.25–37 The number in the inner mitochondrial membrane.of published articles reporting clinical research on ALA-PDT has increased exponentially since the year 1992. As Regulation of the Heme Synthesis Pathway

All the enzymes in the heme pathway act irreversibly.no comprehensive review of clinical ALA-PDT has ap-peared since 1992, we now review the recent data on The pathway is partly regulated by substrate availabil-

ity and feedback inhibition of ALAS. The concentra-clinical ALA-based PDT and diagnosis and discuss thefuture challenges of this promising treatment modality. tions of substrates and intermediates are usually far

below the Michaelis constants of all the enzymes in-Brief sections on regulation of heme synthesis and onlight dosimetry for ALA-PDT are also included. volved.45 Of all the enzymes in the pathway, ALAS has

the lowest activity, followed by PBGD, whereas theother enzymes have much higher activities. In humanREGULATION OF HEME SYNTHESIS

Heme Synthesis erythroid cells, ferrochelatase activity is also low, beingonly about three-fold higher than that of ALAS.45The initial step in the heme synthesis pathway is the

formation of ALA. In mammals and photosynthetic A main regulatory step in the heme pathway is

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2284 CANCER June 15, 1997 / Volume 79 / Number 12

mg/cm2), and application time (up to 24 hours)used.60–62 In general, topical application of ALA alonefor less than 4 hours produces PpIX only at the siteof ALA application, whereas the administration for alonger time (up to 14 hours) or combined with skinpenetration enhancers (such as dimethylsulfoxide[DMSO]) leads to a generalized photosensitization ofthe skin (Peng et al., unpublished data). Six hours aftertopical ALA application (5–40%), a minor increase ofporphyrins in erythrocytes and plasma of patients wasobserved; normal levels returned before 24 hours hadpassed. Blood count, transport proteins, and enzymeswere not significantly influenced.63 Generally, ALA-de-rived PpIX fluorescence can not be detected in theskin 24 hours after completion of topical ALA applica-tion. ALA itself does not seem to be toxic to tissueswhen concentrations õ50% in water/oil emulsion byweight are topically applied for at least 48 hours. More-over, no evidence shows toxicity of ALA-derived PpIXon tissues before light exposure. However, during anda few hours after light irradiation, most patients expe-rience a pruritus, prickling or burning sensation in

FIGURE 1. Regulation of heme synthesis is represented. The synthesis light-irradiated areas, a sensation similar to that ob-steps are indicated by solid arrows and the regulatory steps by dashed served in porphyria patients shortly after sun expo-arrows. Encircled ‘‘plus’’ and ‘‘minus’’ signs indicate stimulatory and inhibi- sure. Some patients cannot even tolerate this pain.tory effects, respectively. Mitochondria are indicated as light grey boxes, Such irritant reaction can significantly be reduced bythe nucleus as a dark grey area, and the cytosol as a white area. Bilirubin use of 2% lignocaine gel9 or ‘‘Emla’’ cream (containingand biliverdin are located in endoplasmic reticulum. IRE: iron-responsive 2.5% lignocaine and 2.5% prilocaine),12 by local intra-element; IRF: iron-regulatory factor; TfR: transferrin receptor. cutaneous anesthesia of 1% lignocaine62 or 2% mepi-

vacaine,64 or by spray of a preparation containing 10%lignocaine (Warloe et al., unpublished data). Thus, an-esthetic drugs should routinely be included in thelinked to ALAS activity (Fig. 1). Heme can inhibit the

enzyme directly46 as well as the transcription, transla- cream preparations. Occasionally, some treated le-sions can develop bacterial superinfection.tion, and transport of the protein into mitochondria.

The direct inhibition of the enzyme may, however, beof minor importance, because the inhibition occurs PHARMACOKINETICS AND TOXICITY OF ALA AND

ALA-DERIVED PPIX AFTER SYSTEMIC ALAonly at around 1005 M, whereas the formation of ALASis controlled at 1007 M. It has been suggested that a ADMINISTRATION

ALAfree heme pool at a concentration of about 1007 M isinvolved in this regulation.47 The housekeeping ALAS, Several hospitals have started to use systemic adminis-

tration of ALA for fluorescence diagnosis and PDT ofexpressed in all tissues, and the erythroid specific iso-enzyme are regulated somewhat differently.48–59 More skin, gastrointestinal, and lung cancers.16,17,19,65,66 How-

ever, it is still not clear whether ALA itself is toxic afterdetails of the regulation of heme synthesis and degra-dation have recently been reviewed by us.37 systemic administration. This issue has been debated

for a long time. Although some patients suffer frommild, transient nausea or/and transient abnormalitiesDISTRIBUTION AND TOXICITY OF PPIX INDUCED

BY TOPICAL APPLICATION OF ALA of liver function, it appears that systemic administra-tion of exogenous ALA at a dose lower than 60 mg/kgAlthough little information exists about the tissue dis-

tribution of ALA after topical application, the fluores- (oral) or 30 mg/kg (intravenous) does not result inany neurotoxic symptoms. Moreover, several earliercence of ALA-derived PpIX in normal and diseased

human skin has been found to increase with time after studies have shown no porphyric symptoms in cancerpatients or healthy volunteers with transient or sus-topical ALA application, with a plateau of approxi-

mately 4–14 hours, depending on ALA concentrations tained high plasma ALA levels after single or repeatedsystemic administration of exogenous ALA.67–71 The(2–40%) in formulas, amounts of preparations (30–50

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plasma concentration of ALA (26.8 mmol/L) peaked at 2 hours after a dose of 200 mg/kg. The PpIX concentra-tions declined to the control level by 24 hours, with a60 minutes after a single oral administration of 3.3

mg/kg ALA in a normal human subject, with a half- half-life of approximately 60 minutes. A similar phar-macokinetic pattern was also observed by Hendersonlife (T1/2) of 50 minutes.71 Regula et al.16 measured the

plasma ALA concentrations during fractionated oral et al.80 in the serum of mice receiving intraperitoneal(i.p.) injection of 250–1000 mg/kg ALA. The value ofadministration (at hourly intervals) of 30 or 60 mg/kg

ALA in 13 patients with gastrointestinal tumors. They serum PpIX over a 5-hour period after an i.p. dose of1000 mg/kg ALA was similar to that just after an i.v.found that the mean plasma ALA concentration in 11

patients 6 hours after a fractionated dose of 30 mg/kg dose of 7 mg/kg exogenous PpIX.80 Recently, Webberet al.81 reported a pharmacokinetic study of ALA-de-was 63 mmol/L (standard deviation, 33 mmol/L). The

ALA levels in 2 other patients 6 hours after 60 mg/kg rived PpIX in 4 cancer patients after oral administra-tion of 60 mg/kg ALA. They found that the half-lifealso as a fractionated dose were 116 and 205 mmol/L,

respectively. In contrast, Gorchein and Webber72 of exogenous ALA-derived PpIX was approximately 8hours after a brief distribution phase. Similar resultsfound that the maximum plasma ALA levels in 2 pa-

tients with acute intermittent porphyria were only 9 were also obtained by Egger et al.82 in dogs receivingi.v. injection of 100 mg/kg ALA. Clearly, more workand 12 mmol/L, but with severe neurologic deficit, in-

cluding respiratory paralysis, quadriplegia, and exten- is needed concerning the pharmacokinetics of ALA-derived PpIX.sive autonomic abnormalities. Obviously, administra-

tion of ALA to cancer patients for PDT treatment hasled to much higher plasma ALA levels than those in ALA-Derived PpIX in the Skin

Numerous pharmacokinetic studies of ALA-derivedporphyric patients. Why was ALA-PDT treatment asso-ciated only with mild nausea and occasional vomiting, PpIX in the skin of various species have been per-

formed. These investigations may reflect the accumu-without any forms of neurovisceral symptoms oftenseen in porphyric patients? The reasons for this are lation of circulating PpIX. In most studies, the tech-

niques used were based on a noninvasive spectropho-not known. Nevertheless, it has been reported thatexogenous ALA may penetrate across the blood-brain tofluorometric method to measure in vivo PpIX

fluorescence in skin surface in situ after systemic (i.p./barrier and the central nervous system itself may syn-thesize porphyrins from exogenous ALA.73–75 There- i.v./oral) administration of various doses of ALA.83 In

the skin of mice, dogs and humans, ALA-derived PpIXfore, much care should be taken in clinical trials ofsystemic ALA administration, particularly for the pa- peaks at approximately 3–8 hours and is almost com-

pletely eliminated within 24 hours after systemic ALAtients with porphyria or severe diseases of the liverand kidneys, because acute attacks of hepatic porphyr- administration.60,83 Similar results have also been ob-

tained by fluorescence microscopy84 and chemical ex-ias with neurovisceral symptoms are always associatedwith high urinary excretion of ALA,76 and in this case traction techniques.80,84,85 In fact, such a phenomenon

has been noted for a long time.67,86–88ALA is generally considered to be the most likely neu-rotoxic compound.77,78 Unfortunately, only a marginal An important issue is whether ALA-derived PpIX

present in the skin originates from bone marrow andamount of knowledge is now available concerning thepharmacokinetics and toxicity of exogenously admin- liver via the blood circulation, or is locally synthesized

in the skin itself, or both. A considerable amount ofistered ALA and the relationship between the pharma-cokinetics of ALA and that of ALA-derived PpIX in evidence has shown that the synthesis of ALA-derived

PpIX can take place in situ in the skin. For example,plasma and tissues.The findings that the plasma of porphyric patients local (topical, intradermal, and intracutaneous) appli-

cation of exogenous ALA to normal and diseased skincontains certain ALA levels might suggest that the ratesof ALA excretion from different types of cells prior to of various species led to a porphyrin fluorescence and

subsequently light-induced photosensitization local-the formation of ALA-derived PpIX might be one ofthe reasons for the variability of PpIX production in ized only to the site of previous ALA application.10

Considering that Photofrin (Quadra Logic Tech-various types of cells and tissues in vivo.nologies, Vancouver, Canada) contains approximately5–10% PpIX and Photofrin and hematoporphyrin (aALA-Derived PpIX in Blood

Little information is available about the pharmacoki- more polar dye) are well known to be retained in theskin for several weeks,89,90 why can ALA-derived PpIXnetics of ALA-derived PpIX in humans. Lofgren et al.79

reported that the highest levels of ALA-derived PpIX fluorescence not be detected 24 hours after systemicadministration of exogenous ALA? The most likely ex-in the plasma of rabbits occurred 1 hour after an intra-

venous (i.v.) dose of 50 mg/kg or 100 mg/kg ALA, and planation is that a single high dose of exogenous ALA

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leads to a temporary production of a high amount of standard procedure, an oil-in-water emulsion of ALAis applied to a skin lesion. This emulsion layer is cov-PpIX in the skin. After that, most ALA-derived PpIX is

quickly either metabolized into nonfluorescing heme/ ered by a semipermeable dressing, and the skin lesionis exposed to light, causing a singlet oxygen-inducedbilirubin in the skin or released from the skin and

transported to the liver via the blood. The PpIX and photodamage to the lesion. The concentration of ALAin the emulsion is usually 20%, but it can be variedheme/bilirubin in the liver are further metabolized in

the intestines and excreted into the feces.37 Such a from 2% to 40%, depending on the application time.For example, a cream containing 2–5% ALA appliedexplanation needs to be experimentally confirmed.

Another possibility is that the persisting fluorescence for a time longer than 8–12 hours produces an amountof PpIX similar to that produced by a cream with 20%in the skin of patients given Photofrin is due to other

porphyrins than PpIX. ALA applied for 3 hours (Peng et al., unpublisheddata). The optimal dose is still not known, and theconcentration of 20% ALA is likely to be an overdosePDT OF HUMAN PRIMARY NONMELANOMA SKIN

TUMORS AFTER TOPICAL ALA APPLICATION in some clinical treatments. All of the oil/water emul-sions (cream, lotion, and ointment) applied so farBackground

Nonmelanoma skin cancer is the most common form are commercially available (Glaxal [Roberts Pharm.Corp., Ontario, Canada],9 Unguentum [Merck, Ger-of cancer in fair-skinned populations. The majority

of nonmelanoma skin cancer is basal cell carcinoma many],12,14,62 Doritin [Chemofux, Vienna, Austria],11,64

Essex [Schering Corp., Kenilworth, NJ],13 and De-(BCC) and squamous cell carcinoma (SCC).91,92 In theUnited States alone, more than 500,000 BCCs and coderm [Merck]61). It seems that all the emulsions

work well, and none appears to be superior. The time100,000 SCCs are diagnosed annually. In Australia, theannual incidence of treated nonmelanoma skin cancer for the topical ALA application is usually 3–8 hours,

to allow penetration of ALA into the lesion and synthe-is estimated to be 823 in 100,000, and the rates for BCCand SCC are estimated to be 657 and 166 in 100,000, sis of PpIX. The light source used in most cases is a

laser with a wavelength of approximately 630 nm, butrespectively.93 In the United Kingdom, approximately190,000 new skin tumors are diagnosed every year.94 incoherent light sources such as tungsten lamps, xe-

non lamps, and halogen lamps with suitable red filtersThe mortality from nonmelanoma skin cancers is lowcompared with that from other malignancies, but both are also often used. In general, the total light dose is

60–250 J/cm2 with an intensity of 50–150 mW/cm2mortality and incidence are rising and affectingyounger people. when a laser is used, whereas the dose is 30–540 J/

cm2 with dose rates ranging from 50 to 300 mW/cm2BCC and SCC arise from the epidermis or its ap-pendages. About 45–60% of BCCs are noduloulcera- when a lamp is used. The temperature of the skin

lesions can rise to 39.5–42.57C during topical ALA-tive and 15–35% are superficial.95,96 Currently, bothsurgical and nonsurgical treatments are used for non- PDT when an intensity of 100 mW/cm2 is used.113 The

response to the treatment is usually evaluated clini-melanoma skin cancer, including excisional surgery,Mohs’ surgery, cryosurgery, electrodesiccation and cu- cally within 1–2 months after treatment. The criteria

of therapeutic effectiveness adopted for most clinicalrettage, topical chemotherapy, and radiotherapy.96–98

Systemically administered HpD/Photofrin has also studies are as follows: tumor complete response (CR)is defined as the absence of clinically evidence of tu-been tried in the PDT treatment of nonmelanoma skin

cancer.99–108 Moreover, topically TPPS-based PDT has mor at the site of treatment; partial response (PR) isdefined as a reduction of 50% or more in tumor size;shown promising results in the treatment of

BCCs.109,110 In 1990 Kennedy et al.9 reported the first no response (NR) is defined as a reduction of less than50% in tumor size.treatment of 80 BCCs using topical ALA-PDT with suc-

cess; this was followed by Wolf and Kerl’s report in1991 that xerodermal pigmentosum was removed with Topically ALA-Based PDT for the Treatment of Human

Skin BCC and SCCtopical ALA-PDT.111 ALA-PDT is now widely applied inthe treatment of cutaneous tumors, although these During the past 5 years, more than 10 articles have

reported the use of topically ALA-based PDT for theclinical trials are still at Phases I–II.treatment of BCCs. Table 1 summarizes the clinicalresults. In a total of 826 superficial BCC lesions treated,Standard Procedures for Topical ALA-PDT

So far no proprietary agent has been marketed for the weighted average rates of CR, PR, and NR were87%, 5%, and 8%, respectively, whereas among 208topical PDT of human primary nonmelanoma skin tu-

mors, although a number of different formulations nodular BCC lesions, the corresponding rates were53%, 35%, and 12%, respectively. For superficial BCCs,have been used in various trials.9,11–15,109,110,112 In the

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TABLE 1Summary of Published Clinical Studies Using Topical ALA-PDT in BCC

Total no. of ALA concentration in Light sourcelesions oil/water emulsion and No. (%)(sBCC and (w/w) and time applied wavelength Light dose J/cm2 Follow-up

Source *nBCC) (hrs) (nm) (mW/cm2) CR PR NR (mos)

Kennedy et al. (1990)9 80 20%, 3–6 Tungsten ú600 31.5–540 (150–300) 72 (90) 6 (7.5) 2 (2.5) 2–3Kennedy and Pottier ú300 20%, 3–6 Tungsten ú600 31.5–540 (150–300) 237 (79) — 63 (21)e 3

(1992)10

Warloe et al. (1992)114 94 20%, 3 CVDL, 630 100 (100–150) 90 (96) 4 (4) — 3Svanberg et al. (1992)115 21 20%, 6 Nd: YAGDL, 40–100 (100) 21 (100) — — 3–5

63010* 4 (40) — 6 (60)e

Wolf et al. (1993)11 37 20%, 4–8 Tungsten 30–100 (50–100) 36 (97) 1 (3) — 3–12unfiltered orTungsten ú570

10* 1 (10) 9 (90) —Cairnduff et al. (1994)12 16 20%, 3–6 CVDL, 630 125–250 (150) 8 (50) 8 (50) — 4–21Svanberg et al. (1994)13 55 20%, 4–6 Nd: YAGDL, 60 (110) 55 (100) — — õ14

63025* 25 (100)c — —

Warloe et al. (1995)14 141 20%, 3 CVDL, 630 40–200 (150) 130 (92) 11 (8) — 3–1224a 16 (67) 7 (29) 1 (4)56b 19 (34) 35 (62) 2 (4)

Calzavara-Pinton (1995)15 23 20%, 6–8 ArDL, 630 60–80 (100) 20 (87)c 3 (13)c — 24–3630* 15 (50)c 9 (30)c 6 (20)c

Lui et al. (1995)116 8 20%, 3 Tungsten ú570 100 (19–44) 4 (50)d 3 (37)d 1 (13)d 3Orenstein et al. (1995)61 17 20% ALA / 2% DMSO / Xenon, 600– 100 (?) 17 (100) — — 3

2% EDTA, 4–5 72031* 24 (77) 7 (23) —

Fijan et al. (1995)64 34 20% ALA / 3% DFO, 20 Halogen, 570– 180–300 (50–300) 30 (88) 3 (9) 1 (3) 3–20690

22* 7 (32) 6 (27) 9 (41)Weighted average 826 720 (87) 39 (5) 67 (8)

208* 111 (53) 73 (35) 24 (12)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; BCC: basal cell carcinoma; sBCC: superficial BCC; nBCC: nodular BCC; CVDL: copper vapor-dye laser: Nd: YAGDL; neodymium: Yag-dye laser;

ArDL: argon ion-dye laser; CR: complete response; PR: partial response; NR: no response; EDTA: ethylenediamine tetraacetic acid; DMSO: dimethylsulfoxide; DFO: desferrioxamine.a õ2 mm nBCC.b ú2 mm nBCC, the criteria of clinical evaluation for CR, PR and NR (see text).c Data from repeated treatments.d All treated lesions were evaluated by histopathology 3 mos after PDT.e Assumed data, since the information was not provided.

most trials obtained good results, with CR rates rang- for a total of 41 superficial SCC lesions treated; theserates were similar to those for superficial BCCs. How-ing from 79% to 100%. The two exceptions were trials

by Cairnduff et al.12 and Lui et al.,116 both of which ever, nodular SCCs did not respond well to topicalALA-PDT with the current protocol, although only fewreported a CR rate of only 50%. The reasons for these

exceptions are not known. For nodular lesions, the nodular SCC lesions have been treated so far.It should be pointed out that the superficial le-majority of reports demonstrated a CR rate lower than

50% after a single treatment, but higher ALA concen- sions of BCC and SCC, when evaluated clinically, areoften found to be deeply penetrating lesions examinedtrations and longer application times tended to in-

crease ALA-derived PpIX in the lesions65 and, conse- by histopathology.116 Because there is no clear line ofdemarcation between a ‘‘thin’’ and a ‘‘thick’’ BCC/quently, improve the outcome of the treatment.117

Table 2 shows the results of topical ALA-PDT for SCC lesion, errors resulting from clinical evaluationcan strongly affect the results of ALA-PDT.the treatment of SCCs. The weighted average rates of

CR, PR, and NR were 81%, 14%, and 5%, respectively, The current protocols of topical ALA-PDT are far

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TABLE 2Summary of Published Clinical Studies Using Topical ALA-PDT in SCC

Total no. of ALA concentration inlesions oil/water emulsion (w/ No. (%)(sSCC and w) and time applied Light source and Light dose J/cm2 Follow-up

Source *nSCC) (hrs) wavelength (nm) (mW/cm2) CR PR NR (mos)

Kennedy et al. (1990)9 8 20%, 3–6 Tungsten ú600 31.5–540 (150–300) 6 (75) 2 (25) — 2–3Svanberg et al. (1992)115 5 20%, 6 Nd: YAGDL, 630 40–100 (100) 5 (100) — — 3–5Wolf et al. (1993)11 6 20%, 4–8 Tungsten unfiltered or 30–100 (50–100) 5 (83) 1 (17) — 3–12

Tungsten ú570Calzavara-Pinton (1995)15 12 20%, 6–8 ArDL, 630 60–80 (100) 10 (84)a 1 (8)a 1 (8)a 24–36

6* 2 (33)a 2 (33)a 2 (34)a

Lui et al. (1995)116 5 20%, 3 Tungsten ú570 100 (19–44) 2 (40)b 2 (40)b 1 (20)b 3Orenstein et al. (1995)61 5 20% / 2% DMSO / 2% Xenon, 600–720 100 (?) 5 (100) — — 3

EDTA, 4–52* — 2 (100) —

Weighted average 41 33 (81) 6 (14) 2 (5)8* 2 (25) 4 (50) 2 (25)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; SCC: squamous cell carcinoma; sSCC: superficial SCC; nSCC: nodular SCC; DMSO: dimethylsulfoxide; EDTA: ethylenediamine tetraacetic acid; Nd:

YAGDL: neodymium: Yag-dye laser; ArDL: argon ion-dye laser; CR: complete response; PR: partial response; NR: no response.a Data from repeated treatments.b All treated lesions were evaluated by histopathology 3 mos after PDT.

from ideal for the treatment of nodular BCCs and ALA/PpIX excretion rates in different lesions, or varia-tions in the histopathologic type of BCC.119,121 For ex-SCCs. They have gained low CR rates and high recur-

rence rates (Tables 1 and 2), although several efforts ample, the morphea type of BCC has little or onlyspotty inhomogenous PpIX fluorescence.119 It is note-have focused on a prolonged application of ALA, add-

ing some other useful chemical additives in cream worthy that oral122 or intravenous65 administration ofALA allows PpIX production throughout the superfi-base and repeated PDT procedure (see below) to im-

prove the therapeutic effectiveness. The reasons why cial,65,122 nodular,65,122 and even morphea types122 ofBCC, thereby providing a significant advantage overthe success was only partial are not fully known. Lim-

ited ALA penetration into deep layers of the nodular topical ALA application.lesion is at least one of the causes. The capacity ofALA-derived PpIX production in various histopatho- Topically ALA-Based PDT for the Treatment of Bowen’s

Disease and Actinic Keratosislogic types of the tumors may also have been related.Therefore, analysis of histologic localization of ALA- Nearly all reports (Table 3) demonstrate that topical

ALA-PDT for the treatment of Bowen’s disease (intrae-derived PpIX is useful for optimization of topical ALA-PDT. Selective localization of ALA-derived PpIX fluo- pidermal SCC) has obtained promising CR rates, rang-

ing from 89% to 100%. An exception is the study ofrescence has been shown in the superficial BCC le-sions rather than in the adjacent normal epidermis Fijan et al.,64 which demonstrated a CR rate of only

50%. Furthermore, actinic keratosis may be most sen-after topical application of ALA for 3 hours,21 but thedeep layers of nodular BCCs demonstrated little fluo- sitive to the treatment modality, with a 92% weighted

average CR rate of 116 lesions treated (Table 4).rescence.60,65,118 The penetration of ALA into the deepBCC lesions could be increased by prolonging the timeof topical application of ALA to 12–48 hours.65,119 Improvement of the Therapeutic Effectiveness of Topical

ALA-PDT by Repeated TreatmentsMoreover, both the penetration of ALA and productionof ALA-derived PpIX could be enhanced by using topi- Topical ALA-PDT can be repeated for the lesions that

fail to respond well to previous treatment(s). Re-cal ALA plus DMSO,65 a skin penetration enhancer,120

and desferrioxamine (DFO), an inducer of porphyrin peated treatments were generally much more effec-tive than a single treatment, particularly for the nod-synthesis.64 However, significant variability and heter-

ogeneity of the ALA-derived PpIX fluorescence have ular BCC lesions (Table 5). For example, Svanberget al.13 found that only 16 of 25 nodular BCCs (64%)been observed between and within the BCC le-

sions,65,118 probably due to a short duration of ALA had a CR after a single treatment, whereas 100% CRwas achieved with one additional treatment. Studiesapplication, varying ALA penetrating abilities, varying

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TABLE 3Summary of Published Clinical Studies Using Topical ALA-PDT in Bowen’s Disease

ALA concentration in Light sourceTotal no. oil/water emulsion and No. (%)of (w/w) and time wavelength Light dose J/cm2 Follow-up

Source lesions applied (hrs) (nm) (mW/cm2) CR PR NR (mos)

Cairnduff et al. (1994)12 36 20%, 3–6 CVDL, 630 125–250 (150) 32 (89) 4 (11) — 7–22Svanberg et al. (1994)13 10 20%, 4–6 Nd: YAGDL, 60 (110) 9 (90) 1 (10) — 6–14

630Calzavara-Pinton (1995)15,a 6 20%, 6–8 ArDL, 630 60–80 (100) 6 (100) — — 24–36Morton et al. (1995)62,b 20 50 mg/cm2, 4 Xenon, 630 { 94–156 (55–158) 18 (90) 2 (10) — 12

15Fijan et al. (1995)64,c 10 20% / 3% DFO, 20 Halogen, 570– 180–300 (50–300) 5 (50) — 5 (50) 3–20

690Weighted average 82 70 (85) 7 (9) 5 (6)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; DFO: desferrioxamine; CVDL: copper vapor-dye laser; Nd-YAGDL: neodymium: Yag-dye laser; ArDL: argon ion-dye laser; CR: complete response;

PR: partial response; NR: no response.a Data from repeated treatments.b Eight of 20 lesions were given a second treatment.c Seven of 10 lesions were given repeated treatments.

TABLE 4Summary of Published Clinical Studies Using Topical ALA-PDT in Actinic Keratosis

ALA concentration inTotal no. oil/water emulsion No. (%)of (w/w) and time Light source and Light dose J/cm2 Follow-up

Source lesions applied (hrs) wavelength (nm) (mW/cm2) CR PR NR (mos)

Kennedy et al. (1990)9 10 20%, 3–6 Tungsten ú600 31.5–540 (150–300) 9 (90) — 1 (10)? 18Wolf et al. (1993)11 9 20%, 4–8 Tungsten unfiltered 30–100 (50–100) 9 (100) — — 3–12Calzavara-Pinton (1995)15 50 20%, 6–8 ArDL, 630 60–80 (100) 50 (100)a — — 24–36Morton et al. (1995)62 4 50 mg/cm2, 4 Xenon, 630 { 15 94–156 (55–158) 4 (100) — — 12Fijan et al. (1995)64 43 20% / 3% DFO, 20 Halogen, 570–690 180–300 (50–300) 35 (81) — 8 (19) 3–20Weighted average 116 107 (92) — 9 (8)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; DFO: desferrioxamine; ArDL: argon ion-dye laser; CR: complete response; PR: partial response; NR: no response.a All lesions were given repeated treatments.

of Warloe et al.14 and Fijan et al.64 also showed that nificantly increased in the nodular lesions, espe-cially in the lesions less than 2 mm thick (Table 6).repeated treatments increased CR rates of nodular

BCC from 34% to 68% and from 32% to 59%, respec- Good results were also obtained by Orenstein et al.61

in the treatment of nodular BCCs with DMSO/EDTA.tively.Thus, the therapeutic effectiveness of topical ALA-PDT for nodular lesions may be improved by usingImprovement of the Therapeutic Effectiveness of Topical

ALA-PDT by the Use of DMSO/EDTA/DFO or Curettage skin penetration enhancers in combination withporphyrin production inducers. However, the actualThe relatively poor results of topical ALA-PDT in the

treatment of nodular BCCs and SCCs may be due to a role EDTA plays in the clinical treatment is still notclear. In addition, DFO enhanced the fluorescencelimited tissue penetration of ALA and an inadequate

production of ALA-derived PpIX. Warloe et al.14 have intensity of PpIX in the skin lesions after topical ap-plication of ALA for 20 hours,64 and a better thera-treated a large number of BCC lesions with ALA

cream containing DMSO and ethylenediamine tetra- peutic effect would be expected in such cases. Re-cently, Warloe et al. have tried a curettage procedureacetic acid (EDTA). Although the CR rate was not

improved in the case of superficial BCCs, it was sig- to reduce tumor volume and remove the surface

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TABLE 5Comparison of CR Rates of Primary Nonmelanoma Skin Tumors after Single and Repeated Topical ALA-PDT

CR no.Light source CR no. (%) (%)

Total no. ALA dose and time and wavelength Light dose (J/cm2 (single (repeatedSource Tumor of lesions applied (hrs) (nm) (mW/cm2) PDT) PDT)

Svanberg et al. (1994)13 nBCC 25 20%, 4–6 Nd:YAGDL, 630 60 (110) 16 (64) 25 (100)Warloe et al. (1995)14 sBCC 141 20% ALA alone, 3 CVDL, 630 40–200 (150) 130 (92) 137 (97)

125 ALA / DMSO/EDTA,a 3 114 (91) 116 (93)nBCC õ 2 mm 24 20% ALA alone, 3 16 (67) 17 (71)

65 ALA / DMSO/EDTA, 3 59 (91) 62 (95)nBCC ú 2 mm 56 20% ALA alone, 3 19 (34) 38 (68)

45 ALA / DMSO/EDTA, 3 25 (55) 27 (60)Halogen, 570–

Fijan et al. (1995)64 sBCC 34 20% / 3% DFO, 20 690 180–300 (50–300) 30 (88) 33 (97)nBCC 22 7 (32) 13 (59)Bowen’s disease 10 3 (30) 5 (50)

Xenon, 630 {Morton et al. (1995)62 Bowen’s disease 20 50 mg/cm2, 4 15 94–156 (55–158) 12 (60) 20 (100)

Actinic keratosis 4 3 (75) 4 (100)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; CR: complete response; nBCC: nodular basal cell carcinoma; sBCC: superficial basal cell carcinoma; DMSO: dimethylsulfoxide; EDTA: ethylenediamine

tetraacetic acid; DFO: desferrioxamine; Nd: YAGDL: neodymium: Yag dye laser; CVDL: copper vapor-dye laser.a Twenty percent ALA (w/w) plus 2–20% DMSO and 2–4% EDTA as additives in oil/water emulsion.

TABLE 6Comparison of Topical ALA-PDT of BCCs with or without DMSO/EDTAa

No. (%)Total no.

Tumor/emulsion of lesions CR PR NR

sBCCALA aloneb 141 130 (92) 11 (8) —ALA/DMSO/EDTAc 125 114 (91) 8 (7) 3 (2)

nBCC õ 2 mmALA alone 24 16 (67) 7 (29) 1 (4)ALA/DMSO/EDTA 65 59 (91) 4 (6) 2 (3)

nBCC ú 2 mmALA alone 56 19 (34) 35 (63) 2 (3)ALA/DMSO/EDTA 45 25 (55) 16 (36) 4 (9)

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; BCC: basal cell carcinoma; nBCC: nodular BCC; sBCC: superficial BCC; DMSO: dimethylsulfoxide; EDTA: ethylenediamine tetraacetic acid; CR:

complete response; PR: partial response; NR: no response.a Data adapted from Warloe et al.14

b Twenty percent ALA (w/w) in cream base applied to tumor for 3 hrs before light exposure.c Twenty percent ALA (w/w) plus 2–20% DMSO and 2–4% EDTA as additives in cream base.

structure of 152 nodular tumors before ALA-PDT. clinical response rates have usually been evaluatedwithin 1–2 months after treatment. In most studiesSuch a procedure achieved 85% CR with a follow-up

of 3 – 6 months (Warloe et al., unpublished data). the follow-up is too short to draw any sensible conclu-sions. Table 7 provides the information available sofar in the literature as to the difference in CR ratesComparison of CR Rates between Initial Clinical

Evaluation and ‘‘Long Term’’ Follow-Up or between initial clinical evaluation and ‘‘long term’’ fol-low-up or histopathologic evaluation after treatmentHistopathologic Evaluation after Topical ALA-PDT

Although topical ALA-PDT has achieved promising re- of various cutaneous diseases. All initial clinical CRrates decreased after ‘‘long term’’ follow-up or histo-sults in the treatment of superficial skin lesions, the

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TABLE 7Summary of Short Term versus ‘‘Long Term’’ CR Rates in Topical ALA-PDT of Primary Nonmelanoma Skin Tumors

ShortTotal term Evaluation Longno. of ALA dose and time Light source and Light dose J/cm2 CR no. time term CR

Source Tumor lesions applied (hrs) wavelength (nm) (mW/cm2) (%) (mos) no. (%) Follow-up (mos)

Wolf et al. (1993)11 sBCC 37 20%, 4–8 Tungsten unfiltered or 30–100 (50–100) 37 (100) 1–2 36 (97) Median, 7Tungsten ú570

Cairnduff et al. (1994)12 sBCC 16 20%, 3–6 CVDL, 630 125–250 (150) 14 (88) 2 8 (50) Median, 17Bowen’s disease 36 35 (97) 32 (89) Median, 18

Calzavara-Pinton (1995)15,a sBCC 23 20%, 6–8 ArDL, 630 60–80 (100) 23 (100) 1 20 (87) 24–36nBCC 30 24 (80) 15 (50)sSCC 12 11 (92) 10 (83)nSCC 6 4 (67) 2 (33)Bowen’s disease 6 6 (100) 6 (100)Actinic keratosis 50 50 (100) 42 (84)Keratoacanthoma 4 4 (100) 4 (100)

Lui et al. (1995)116 sBCC 8 20%, 3 Tungsten ú570 100 (19–44) 7 (88) 1–2 4 (50) 3 (by histopathology)Morton et al. (1995)62 Bowen’s disease 20 50 mg/cm2, 4 Xenon, 630 { 15 94–156 (55–158) 20 (100) 2 18 (90) 12Warloe et al. (1995)14 sBCC 393 ALA alone or ALA/ CVDL, 630 40–200 (150) 369 (94) 3 360 (92) 7–18 (and by

DMSO/EDTA,b 3 histopathology)nBCC 326 245 (75) 233 (71) Median, 10

ALA-PDT: 5-aminolevulinic acid–based photodynamic therapy; CR: complete response; sBCC: superficial basal cell carcinoma; nBCC: nodular basal cell carcinoma; sSCC: superficial squamous cell carcinoma;

nSCC: nodular squamous cell carcinoma; DMSO: dimethylsulfoxide; EDTA: ethylenediamine tetraacetic acid; CVDL: copper vapor-dye laser; ArDL: argon ion-dye laser.a All lesions were given repeated treatments.b Used to treat a total of 393 sBCC lesions, 141 receiving 20% ALA alone, 125 receiving ALA plus 2–20% DMSO/2–4% EDTA, and 127 receiving 50–90% DMSO applied 15 min prior to application of ALA alone or

ALA plus DMSO/EDTA. Used to treat a total of 326 nBCC lesions, 80 receiving ALA alone, 110 receiving ALA/DMSO/EDTA, and 136 receiving DMSO as pretreatment.

pathologic evaluation except in the study of Calzavara- fiberoptic cylinders into deep lesions may be useful,but this still remains to be determined. In addition,Pinton, which still demonstrated 100% CR rates of

Bowen’s disease and keratoacanthoma after a long fractionated irradiation could result in a faster regres-sion of the lesions, but the effects of split light doseterm follow-up of 24–36 months.15 In most studies the

initial CR rates did not significantly decrease after long and light intensity on the CR rate need to be studied.term follow-up, but in four trials of BCC (two superfi-cial and two nodular),12,15,116 the CR rates were remark- TOPICALLY ALA-BASED PDT OF OTHER TUMORS

Warloe et al.14 treated patients with nevoid basal cellably decreased from initial 67–88% to 33–50% after amedian follow-up of 17–36 months or 3 months of carcinoma syndrome (Gorlin’s syndrome) who had a

total of 11 superficial and 26 nodular BCC lesions, andhistopathologic evaluation. Thus, a full picture of thetherapeutic effectiveness of topical ALA-PDT for cuta- the CR rates of the superficial and nodular lesions were

only 61% and 12%, respectively. Karrer et al.123 foundneous lesions requires data on a long term follow-upor histopathologic confirmation. good results in a patient with Gorlin’s syndrome who

had multiple BCCs and failed to respond to conven-tional methods including surgical excision, cryother-Effect of Light Dose on the Results of Topical ALA-PDT

Little information is available regarding the effect of apy, and ionizing radiotherapy.Eighteen patients with vulval or vaginal carcino-light dose on the response rates of skin lesions to topi-

cal ALA-PDT. So far the light dose applied is within a mas in situ were treated with topical ALA-PDT at theNorwegian Radium Hospital (Kristensen et al., unpub-wide range of 60–250 J/cm2 for laser sources and 30–

540 J/cm2 for nonlaser sources. In many clinical trials lished data). All the tumors showed a strong fluores-cence after topical ALA application for 4 hours, butthe light exposure has been overdosed. Is the CR rate

of treatment proportional to the light dose applied? only approximately 50% of the treated lesions had CR.The reason for this is not understood, but we foundWarloe et al.14 failed to find a clear proportional rela-

tion between the CR rate and light dose used. How- that the ALA-derived porphyrin fluorescence in thetreated lesion biopsies was completely photobleachedever, it appears that doses ranging from 50 to 90 J/

cm2 at an intensity of 150 mW/cm2 are required to by the light exposure (100–150 J/cm2) (Peng et al.,unpublished data).achieve good results of the treatment in both superfi-

cial and nodular BCCs.14 For the very superficial le- Recently, CR of cutaneous T-cell lymphoma hasbeen reported after topical ALA-PDT.117,124 Wolf et al.125sions, such as Bowen’s disease, even lower doses may

be used. For nodular tumors, interstitial insertion of emphasized that repeated topical ALA-PDT is im-

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portant in treating the cutaneous T-cell lymphoma, various time intervals after the topical application of2.5% or 20% ALA. They found that both in vivo fluo-because the results obtained by both Ammann and

Hunziker126 and Svanberg et al.13 were disappointing rescence imaging in situ and fluorescence microscopyof biopsies showed selective fluorescence of ALA-de-after a single topical ALA-PDT. We observed a strong

fluorescence of ALA-derived porphyrins in the tumor rived PpIX in the labia minora and vestibule of condy-lomas within short time intervals, particularly in thecells of a patient with cutaneous T-cell lymphoma

(Peng et al., unpublished data). Similarly, by means of lesions located in the areas of non-hair-bearing skin,indicating that ALA-PDT could have a potential forlaser-induced fluorescence measurements, Svanberg

et al.13 found the ratio of fluorescence intensity be- ablation of genital CA. Furthermore, the ratio of epi-thelial condyloma fluorescence to adjacent skin 1.5tween T-cell lymphomas and surrounding normal tis-

sue to be 5:1. This may have been due to a lack of hours after ALA application was higher with 2.5% ALAthan with 20% ALA.133 Similarly, we studied 3 cases offerrochelatase in the mitochondria of the aberrant T-

lymphocytes that led to an accumulation of endoge- vulval CA and found that all the lesions demonstrateda strong ALA-derived PpIX fluorescence after topicalnous porphyrins.127

So far, all three reported clinical trials of topical 20% ALA application for 4 hours (Peng et al., unpub-lished data).ALA-PDT for metastatic nodular breast carcinoma

have achieved poor results,9,12,115 probably due to the It is noteworthy that topical ALA application toskin induces an accumulation of PpIX not only in thefact that the periphery of the metastatic tumors lay

beneath the normal skin, where it is difficult for ALA epidermis but also in its adnexa (including hair folli-cles and sebaceous glands) in mice,84,134 dogs, and hu-to penetrate. Wolf et al.11 have also reported ALA-PDT

to be a therapeutic failure in the treatment of metasta- mans.60 Consequently, topical ALA-PDT could providepotential uses for treatment of disorders originatingses from malignant melanoma.from the skin appendages. A preliminary study hasshown that topical ALA-PDT could be useful in treat-TOPICALLY ALA-BASED PDT OF HUMAN

NONNEOPLASTIC SKIN DISEASES ing hirsutism by permanently damaging hair folli-cles.135 Grossman et al.135 reported that 3 months afterAlthough topical ALA-PDT has most often been em-

ployed to date in the treatment of skin tumors, its PDT with topical 20% ALA and 200 J/cm2 , only 50%of the treated sites had hair regrowth, and the adjacentpotential use is far beyond dermatologic oncology.

Boehncke et al.128 treated 3 patients with chronic dermis was not damaged. Furthermore, acne, a disor-der of sebaceous glands, could be another potentialplaque-stage psoriasis every other day with PDT, using

a topical application of 10% ALA for 5 hours before indication for this modality. We have also observedsome fluorescence of ALA-derived PpIX in eczematouslight exposure at a dose of 25 J/cm2 (70 mW/cm2), and

achieved promising results. Nelson et al.129 treated 14 lesions (Peng et al., unpublished data).patients with psoriasis with 10–20% ALA and UVA lightexposure weekly for a total of 4 times. About half of SYSTEMICALLY ADMINISTERED

HEMATOPORPHYRIN/HEMATOPORPHYRINthe treated lesions improved by more than 50% after4 weekly treatments. We studied 20 psoriatic biopsies DERIVATIVES-BASED PDT FOR HUMAN PRIMARY

NONMELANOMA SKIN TUMORStaken from 6 patients after topical 20% ALA applica-tion and found that psoriatic lesions can produce a In 1978 Dougherty et al.136,137 reported a pioneering

clinical study in which systemically administeredstrong but unevenly distributed PpIX fluorescence(Peng et al., unpublished data). Similar results were hematoporphyrin derivative (HpD)-PDT was used to

treat 5 BCC lesions with a 100% CR rate at a follow-obtained by others.130

Both Kennedy et al.9 and Ammann et al.131 ob- up of 12 months. Since then, a number of similar clini-cal trials have been performed in the treatment of pri-served a poor response of refractory verrucae vulgaris

to topical ALA-PDT with application of a 20% ALA mary nonmelanoma skin tumors.99–106 Table 8 pres-ents a summary of the majority of published data. Incream for 3–6 hours followed by light exposure from

a slide projector. addition, the reports of McCaughan,153 Bandieramonteet al.,154 Gregory and Goldman,112 Waldow et al.,143 andFrank et al.132 treated 7 genital condyloma acumi-

natum (CA) lesions, applying 20% ALA topically for 14 Petrelli et al.155 have shown promising results for BCCs,SCCs, and Bowen’s disease, although they are not in-hours before light exposure of a argon dye laser with

a dose of 100 J/cm2 at an intensity of 75 or 150 mW/ cluded in Table 8. As can be seen from Table 8, themajority of the studies employed HpD/Photofrin andcm2 . They obtained CR in 4 of 7 lesions after 3 months.

Fehr et al.133 studied in detail the distribution of ALA- laser systems with a time interval of 24–120 hoursbetween systemic drug administration and light expo-derived PpIX in the vulvar CA lesions of 24 patients at

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TABLE 8Summary of Published Data on Hp/HpD/Photofrin/Photosan-3-based PDT for the Treatment of Primary Nonmelanoma Skin Tumors

Light sourceNo. (%)Total Time and

no. of Drug/dose interval wavelength Light dose J/cm2 Follow-up RecurrenceSource Tumor lesions (mg/kg)a (hrs) (nm) (mW/cm2) CR PR NR (mos) rate (%)

Dougherty et al. (1978)136,137 BCC 5 HpD/2.5–5 96 Xenon 600– 120 (100) 5 (100) — — 12 ?700

Kennedy (1983)138 BCC 38 HpD/2.5 96–120 Tungsten ú 90 (?) 38 (100) — — 35 ?600

Tse et al. (1984)139 BCCe 40 HpD/3 72 Xenon 600– 38–180 (21–50) 33 (82.5) 7 (17.5) — 12–14 10.8b

700 orArDL 630

Tomio et al. (1984)140 BCC 7 Hp/5 24–48 He/NeL 30–70 (125) 4 (57) 2 (29) 1 (14) ? ?Cai et al. (1985)141 BCC 23 HpD/5 48–72 ArDL 630 150–400 (250–400) 17 (74) 3 (13) 3 (13) ?–39 ?Pennington et al. (1987)142 BCC 21 HpD/5 72 ArDL 630 30? 11 (52) 10 (48) — 6 100Waldow et al. (1987)143 BCC 6 Pf/1.5–2 24–72 ArDL 630 40–60 (29–90) 6 (100) — — 4–24 17Wilson et al. (1989)144 BCC 151 Pf/1 48–72 ArDL 630 180–225 (150) 133 (88) 18 (12) — 12 10Buchanan et al. (1989)145 BCC ú13 HpD/3–4 72 GVL 628 or 50–100 (?) 10 (77) 3 (23) — ? 50

or Pf/ ArDL 6301.5–2

Keller et al. (1989)146 BCC 6 HpD/2–3 48–72 ArDL 630 150–250 (80–200) 6 (100) — — 48 0or Pf/1

McCaughan et al. (1989)147,c BCC 27 HpD/3 or 48–144 ArDL 630 20–30 (?) 16 (59) 10 (37) 1 (4)f 12 75Pf/2

Feyh et al. (1990)148 BCC 29 Ps/? 48 ArDL 630 100 (100) 29 (100) — — 14 3.5Wilson et al. (1992)149 BCC 151 Pf/1 48–72 ArDL 630 72–288 (150) 133 (88) 18 (12) — 20–43 16

(mean,29)

Svanberg et al. (1992)115 BCC 15 Pf/1–2 ? Nd: YAGDL 40–100 (100) 15 (100) — — 3–5 0630

Hintschich et al. (1993)150 BCC (eyelid) 21 Ps/2 48 ArDL 630 100 (100) 21 (100) — — 3–20 48(mean;10)

Weighted average BCC 553 477 (86) 71 (13) 5 (1)

Cai et al. (1985)141 SCC 16 HpD/5 48–72 ArDL 630 150–400 (250–400) 7 (44) 5 (31) 4 (25) ?–39 ?Pennington et al. (1987)142 SCC 32 HpD/5 72 ArDL 630 30 (?) 26 (81) 6 (19) — 6 50Keller et al. (1989)146 SCC 2 HpD/2–3 48–72 ArDL 630 150–250 (80–200) 2 (100) — — 48 0

or Pf/1McCaughan et al. (1989)147,c SCC 5 HpD/3 or 48–144 ArDL 630 20–30 (?) 3 (60) 1 (20) 1 (20) 12 40

Pf/2Feyh et al. (1990)148 SCC 5 Ps/? 48 ArDL 630 100 (100) 5 (100) — — 14 0Weighted average SCC 60 43 (72) 12 (20) 5 (8)

Robinson et al. (1988)151 Bowen’sd ú500 Pf/2 72 GVL 628 25–50 (?) ú500 (100) — — 6 0Buchanan et al. (1989)145 Bowen’s ú50 HpD/3–4 72 GVL 628 or 25–50 (?) 50 (100) — — ? ?

or Pf/ ArDL 6301.5–2

McCaughan et al. (1989)147,c Bowen’s 2 HpD/3 or 48–144 ArDL 630 20–30 (?) 2 (100) — — 12 50Pf/2

Jones et al. (1992)152 Bowen’s 8 Pf/1 48 ArDL 630 185–250 (150) 8 (100) — — 14–24 0Weighted average Bowen’s 560 560 (100) — —

Hp: hematoporphyrin; HpD: hematoporphyrin derivative; Pf: Photofrin; Ps: Photosan-3, a product similar to HpD; PDT: photodynamic therapy, BCC; basal cell carcinoma; SCC: squamous cell carcinoma; Bowen’s:

Bowen’s disease; He/NeL: helium neon laser; ArDL: argon ion-dye laser; GVL: gold vapor laser; Nd: YAGDL: neodymium: Yag-dye laser; CR: complete response; PR: partial response; NR: no response.a All drugs were given intravenously.b Recurrence rate was based on 37 lesions, as 3 were later treated with Mohs’ surgery.c All data were based on the no. of treatment sessions rather than the no. of lesions.d This study included some BCC lesions, but the exact no. is not provided.e Nevoid basal cell carcinoma syndrome (Gorlin’s syndrome).f Assumed data, since the information is not provided.

sure. Some used also hematoporphyrin (Hp) or Pho- lesions were treated achieved a 100% initial CRrate,115,136,138,143,146,148,150 whereas 3 studies involving 31tosan-3 (Seelab, Wesselburenerkoog, Germany), a sim-

ilar agent to HpD. In 15 trials of PDT, involving a total lesions only obtained a CR rate of approximately50%.140,142,147 Moreover, recurrence rates after treat-of 553 BCC lesions, the average CR, PR, and NR rates

were 86%, 13%, and 5%, respectively. However, there ment varied from 0%146 to 100%,142 with most follow-ups longer than 10 months. Obtaining results similarwas wide variation among CR rates in the different

studies. For example, 7 trials in which a total of 120 to those with ALA-PDT, Wilson et al.149 found that a

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TABLE 9Comparison of Topical ALA-PDT and Systemic HpD/Photofrin-PDT for the Treatment of Skin Cancer

ALA-PDT1) Convenient; available on an outpatient basis2) Low-cost (ALA is cheaper than Photofrin, and ordinary lamps with suitable filters can be used)3) No toxicity or interaction with other medications4) High selectivity leaving the surrounding normal skin intact and functional5) Several separate lesions can be treated simultaneously6) The same lesion(s) can be repeatedly treated7) Cosmetic results are superior to conventional modalities8) No risk of skin photosensitivity after 24 hrs9) Local anesthesia is often required during light exposure

10) Efficient for superficial lesionsHpD/Photofrin-PDT:

1) Relatively inconvenient; patients often stay in the hospital for a few days2) Expensive (laser is used in most cases)3) No systemic toxicity or interaction with other medications4) Selectivity leaving the surrounding normal skin intact and functional5) Several separate lesions can be treated simultaneously6) The same lesion(s) can be repeatedly treated7) Cosmetic results are equal or superior to conventional modalities in most cases8) Risk of skin photosensitivity for at least 4–6 wks9) Local anesthesia is sometimes required during light irradiation

10) More efficient than ALA-PDT in treatment of nodular lesions

second treatment of BCC for PR and recurrent lesions 635 nm, but some investigations were performed withfrom the first PDT increased the CR rate from 88% to other light sources, making direct comparison diffi-97% among 151 treated lesions. cult. Moreover, the treated tumors ranged in size from

In 5 trials involving a total of 60 SCCs, the averages a few mm to more than 20 cm and had pigmentationof CR, PR, and NR were 72%, 20%, and 8%, respec- of varying degrees.tively. Two of the 5 studies had a 100% initial CR rate Advantages and disadvantages of topical ALA-PDTand no recurrences at a follow-up of 14–48 and systemically administered HpD/Photofrin-basedmonths,146,148 whereas the other 3 trials achieved only PDT of primary nonmelanoma skin tumors are sum-44–81% initial CR rates with 40–50% recurrence rates marized in Table 9. Although both modalities are suit-at a follow-up of 6–12 months.141,142,147 In contrast, all able for treatment of superficial cutaneous tumors,4 studies of PDT, involving a total of 560 lesions of Photofrin is the most widely used photosensitizer inBowen’s disease, had a consistent 100% CR rate with clinical PDT trials and is the only agent that has beenrecurrence of only 1 lesion at a follow-up of 6–24 approved for several clinical indications in Japan, Can-months.145,147,151,152

ada, the Netherlands, the United States, and France.Moreover, with the current protocol, Photofrin-PDTappeared more efficient than topical ALA-PDT in de-COMPARISON OF ALA-PDT WITH HPD/PHOTOFRIN-stroying cutaneous lesions. The main disadvantage ofPDT AND WITH CONVENTIONAL TREATMENTusing Photofrin-PDT is the risk of prolonged skin pho-MODALITIEStosensitivity.Different studies have shown a wide variation in the

Several studies have shown that the location ofresponses of nonmelanoma primary skin tumors toBCCs is an important factor affecting PDT re-ALA-PDT and HpD/Photofrin-PDT. This could be duesults.149,150,156 For example, BCCs located on the noseto a lack of controlled clinical PDT trials (includingor eyelid had higher PR and higher recurrence ratestreatment protocols and patient selection criteria). Inafter Photofrin-PDT than those located at othergeneral, PDT outcome depends on the type andsites.149,150 Such a ‘‘site effect’’ has also been seen inamount of sensitizing agent absorbed by the tumor,topical ALA-PDT of solar keratoses (SK). Wolf et al.157light wavelength, depth of light penetration into theachieved 93.6% CR in 204 SK lesions on the face, scalptumor, and light energy delivered. In most studies, the

light source was a laser emitting at approximately 630– or neck, whereas only 48.9% CR was achieved in le-

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sions on the forearm or the dorsum of the hand. Simi- recurrence rates during short term and long term fol-low-ups, although the results vary substantially, prob-lar findings were also obtained by Szeimies et al.158

Apparently, the amount and tissue distribution of ALA- ably due to variation in the location, size, and histo-pathologic subtype of BCCs and to the physician’s ex-derived PpIX fluorescence can vary from one part to

another of the skin10 as well as of skin lesions.157 Ban- perience. With current protocols, PDT in which ALAor HpD/Photofrin is used does not seem to be superiordieramonte et al.154 treated 42 BCC lesions with HpD-

PDT and obtained a CR rate of approximately 50%. to conventional treatments for skin tumors, but someindividual clinical PDT trials have achieved compara-They found that small, persistent areas of BCC ap-

peared to be related to high pigmentation of the le- ble or favorable results with outstanding cosmetics,particularly in cases of large and multiple lesions. Insions or to the ‘‘border effects’’ (an insufficient dose

of light at the border) when irradiation was performed addition, successful results with PDT of skin tumorshave recently been obtained using second-generationwith multiple adjacent fields. Similarly, a study by Cal-

zavara-Pinton showed no effect of topical ALA-PDT on photosensitizers, such as benzoporphyrin derivativemonoacid ring A (BPD-MA),160,161 tin-ethyl etiopurp-pigmented BCCs.15

Cutaneous SCCs are not as sensitive as BCCs to urin (SnET2),162 and mono-l-aspartyl chlorin e6(NPe6).163,164 These second-generation dyes have aPDT with ALA or HpD/Photofrin.138 The neoplastic

cells of SCCs may not produce ALA-derived PpIX or larger absorption peak (approximately 660–690 nm)than PpIX/HpD/Photofrin and much less risk of pro-selectively uptake HpD/Photofrin as much as the neo-

plastic cells of BCCs (Peng et al., unpublished data). longed cutaneous photosensitivity.In addition, some superficial SCCs evaluated clinicallywere actually those that infiltrated into deeper layers SYSTEMICALLY ADMINISTERED ALA-BASED PDT

FOR HUMAN TUMORS OF THEof the skin, where the lesions might not receive enoughALA and/or light irradiation.116 AERODIGESTIVE TRACT

In 1993 Grant et al.165 reported that ALA-derived PpIXIt should be pointed out that PDT is, in general,still considered a palliative modality rather than a first peaked at 4–6 hours in oral cavity SCCs of all 4 patients

examined after oral administration of 30–60 mg/kgtreatment for most cancer patients. Therefore, mostpatients receive multiple therapies prior to PDT, such ALA, and returned to background within 24 hours.

Similar kinetics of ALA-derived PpIX were also ob-as ionizing radiation, surgical excision, cryotherapy,topical 5-fluorouracil, electrodesiccation, or curettage. tained in sigmoid colorectal adenocarcinoma of 3 pa-

tients subsequent to oral administration of ALA atIn other words, the majority of patients fail or recuron multiple other therapies prior to PDT. This situa- doses of 30 or 60 mg/kg.166 In general, there is no

gastrointestinal (GI) tumor selectivity (relative to sur-tion may reduce PDT efficiency, particularly in casesof topical ALA-PDT. Moreover, a comparison of the rounding normal mucosa) of ALA-derived PpIX with a

dose lower than 40 mg/kg, although wide variationtreatment results of skin tumors achieved with differ-ent therapies should be limited to lesions of similar was seen from one patient to another (Peng et al.,

unpublished data). However, the selectivity of ALA-size, location, and histopathologic type. In addition,general medical conditions of patients should be con- derived PpIX appeared to be improved by using a

higher dose (60 mg/kg),166 and the PpIX ratio of tumorsidered.Topical ALA-PDT has several potential advantages to normal mucosa was found to be about 5:1 in colon

carcinomas.16,167 In addition, ALA-derived PpIX levelsover conventional therapies. It is noninvasive, has ashort photosensitization period, produces excellent were found to be higher in tumors of the esophagus,

duodenum, and lowest part of the large bowel than incosmetic results, and is well tolerated by patients.Moreover, it can be used to treat multiple superficial colorectal tumors, but doubling the ALA dose in-

creased significantly the amount of PpIX in the colo-lesions in short treatment sessions, patients who re-fuse surgery or have pacemakers and bleeding ten- rectal tumors.16,167 With ALA-PDT, Fan et al. obtained

CR only in 2 of 7 oral SCCs after oral administrationdency, and lesions in specific locations such as theoral mucosa or the genital area. It can be used as a of 60 mg/kg ALA (divided into 3 equal fractions over

2 hours), followed by light exposure (628 nm) up topalliative treatment, and it can be applied repeatedlywithout cumulative toxicity. However, for a new mo- 200 J/cm2 (up to 200 mW/cm2), but all 13 premalignant

lesions treated obtained full-thickness epithelial ne-dality to become clinically acceptable as a routinetreatment, it must possess a therapeutic advantage crosis and elimination of dysplastic epithelium.168

Similarly, 8 of 10 patients with GI tumors given a redover existing conventional treatments. For example,as shown in Table 10,159 several conventional modal- laser light exposure (628 nm) at a dose of 50–100 J/

cm2 (50 mW/cm2) after ALA administration demon-ities are available for the treatment of BCCs with low

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TABLE 10Summary of Short Term versus Long Term BCC Recurrence Rates with Conventional Treatment Modalitiesa

Recurrence rate

Short term (õ5 yrs) Long term (5 yrs)

Modality Range (%) Average (%) Range (%) Average (%)

Surgical excision 0–10.3 2.8 (157/5560) 1.2–23.4 10.1 (264/2606)Curettage and electrodesiccation 1.8–25 4.7 (173/3664) 1.2–18.8 7.7 (274/3573)Radiation therapy 2.8–10 5.3 (319/6072) 4.1–31 8.7 (485/5549)Cryotherapy 0–12.0 3.7 (90/2462) 7.5 7.5 (20/269)Mohs’ surgery 1.4 1.4 (5/367) 0.7–1.8 1.0 (73/7670)

BCC: basal cell carcinoma.a Adapted by permission of the publisher from Rowe et al.159 Copyright 1989 by Elsevier Science Inc.

strated a only superficial necrosis of the tumors (0.5– 3% ALA solution for 2 – 3 hours followed by fluores-cence cystoscopy with violet light from a krypton ion1.5 mm in depth).16 Mlkvy et al.169 compared the effect

of ALA-PDT (oral, 60 mg/kg, 6 hours before light irradi- laser (406.7 nm) for excitation of ALA-derived PpIX.A sharply marked red fluorescence induced from ALAation) with that of Photofrin-PDT (i.v., 2 mg/kg, 48

hours before light exposure) in the treatment of duo- in the urothelial lesions could be easily observed withthe naked eye during the fluorescence cystoscopy.denal and colorectal polyps in 6 patients with familial

adenomatous polyposis. They found that the PDT-in- The mean ratio of fluorescence intensity betweenurothelial carcinoma and normal urothelium wasduced tumor necrosis was only superficial (up to 1.8

mm in depth) in the case of ALA but much deeper in 17:1. The fluorescence microscopy revealed that thePpIX fluorescence was limited mainly to the urothe-the case of Photofrin. Warloe et al. treated 9 patients

with rectal tubulovillous adenomas with ALA-based or lial layer. Little was detected in the submucosal ormuscle layers of the bladder wall, indicating thatPhotofrin-based PDT after the main bulk of the pri-

mary tumors had been endoscopically resected.170 there may be no direct phototoxic damage to vesselsand muscle cells of the bladder wall. In a group ofNine patients were treated during a total of 14 PDT

sessions, 5 receiving Photofrin and 9 receiving ALA, 104 patients with bladder carcinoma, the sensitivityof the ALA-derived PpIX fluorescence cystoscopy inrespectively. The tumors in all 5 Photofrin-PDT ses-

sions showed complete regression. However, they all detection of neoplastic urothelium was 96.9%, sig-nificantly higher than that of conventional white lightrecurred 4–20 months after treatment. Four of 9 ALA-

PDT recipients achieved CR, and no recurrence was cystoscopy (72.7%).18 A similar finding was also ob-tained by Jichlinski et al.175 Thus, ALA-derived PpIXseen after 3–10 months. In addition, two of the cases

with PR after the first treatment were given a second fluorescence cystoscopy may be useful for detectingthe precise sites of bladder urothelial lesions, espe-ALA-PDT, and both of them showed CR. Thus, system-

ically administered ALA-based PDT is simple and safe cially in cases of suspicious or positive urine cytologicfindings. Moreover, a decrease in recurrence ratesand may be a promising technique for the treatment

of small and superficial mucosal precancerous and may be expected for transurethral resection of blad-der carcinoma performed under violet light after in-cancerous lesions of the aerodigestive tract, such as

dysplasia in Barrett’s esophagus and small tumors.171 travesical ALA instillation. Little information exists asto the use of PDT with intravesical instillation of ALAOptimization of the technique parameters is required

for the larger lesions. for the treatment of superficial urothelial tumors.176

However, intravesical, oral, or i.v. administration ofALA to rats or pigs led not only to an accumulationDETECTION OF EARLY BLADDER CARCINOMA BY

ALA-DERIVED PPIX FLUORESCENCE of ALA-derived PpIX in the urothelium and bladdertumors, but also to a destruction of the lesions afterPrecancerous and cancerous urothelial lesions, such

as tiny dysplasia, carcinoma in situ, or flat papillary light exposure.177– 181 Photofrin and some other fluo-rescent agents have also been tried to detect earlytumors, can be easily missed during conventional

cystoscopy under white light. Recently, Kriegmair et stages of bladder carcinoma.182,183 However, the pro-cedures are subject to considerable disadvantages.al.172 –174 used intravesical instillation of a pH-neutral

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For example, Photofrin is usually given systemically istered ALA-PDT has promise as a treatment for earlystages of lung carcinoma.to a patient, with a risk of skin photosensitivity. More-

over, the fluorescence quantum yield and/or the ab-solute amount of Photofrin are so low that highly DETECTION OF MALIGNANT GLIOMA BY ALA-

DERIVED PPIX FLUORESCENCEsensitive devices are required to detect the Photofrinfluorescence in the urothelial lesions. Finally, the ra- Complete tumor removal by surgery is crucial for long

term survival of patients with malignant glioma. How-tio of the fluorescence intensity of Photofrin betweenchemically induced rat bladder tumors and normal ever, uncritical resection may be deleterious to neuro-

logic function. Thus, techniques are required to pro-rat bladder urothelium was found to be only 2 – 5:1after i.v. injection,184 whereas the ratio of the ALA- vide clear intraoperative tumor identification for opti-

mal tumor resection. Stummer et al.187 triedderived PpIX fluorescence between the same animaltumor model and normal bladder mucosa was shown intraoperative photodetection of ALA-derived PpIX

fluorescence in 3 patients with multiform glioblas-to be 20:1 after topical application of ALA to the uri-nary bladders,185 showing a highly selective accumu- toma. The patients were given 10 mg/kg orally 3 hours

before anaesthesia. The PpIX fluorescence was excitedlation of ALA-derived PpIX in the malignant urothel-ium. by violet blue xenon light and visualized with longpass

filter goggles. Thirty-five biopsies were taken fromfluorescing, neighboring, and nonfluorescing tissuesDETECTION AND PDT OF EARLY-STAGE LUNG

CARCINOMA WITH ALA-DERIVED PPIX for histopathologic evaluation. Normal brain tissuesshowed no PpIX fluorescence, whereas tumor tissuesInhalation of ALA has potential for detecting bronchial

malignancies. Baumgartner et al.186 have reported that that infiltrated adjacent normal brain tissues demon-strated a clear red fluorescence. Such a method pro-4 patients with positive sputum cytology but negative

white light bronchoscopy received a 10% NaCl-ALA vided 85% sensitivity and 100% specificity for the de-tection of malignant glioma tissues. This suggests thatsolution by means of a conventional nebulizer. Three

hours after inhalation, patients were examined by ALA-PDT of brain tumors could be possible with ahigh therapeutic selectivity.fluorescence bronchoscopy. ALA-derived PpIX fluo-

rescence spectra could be clearly recorded, and thePpIX fluorescence in several dysplastic areas was im- LIGHT DOSIMETRY FOR ALA-PDT

Choice of Light Sourceaged. Moreover, Huber et al.19 studied 7 patients withlung malignancies; 250 or 500 mg ALA dissolved in 5 A number of different light sources are being used

in clinical and experimental PDT—lasers as well asml saline were inhaled with a PARI-boy jet-nebulizer,and the endobronchial ALA deposition was estimated nonlaser light sources (including light-emitting diode

arrays, fluorescent tubes, and incandescent lamps),to be 25 mg and 50 mg, respectively. Fluorescencebronchoscopy was also performed 3 hours after inha- continuous as well as pulsed sources. A laser offers

significant advantages whenever fiberoptics arelation, and biopsies were taken. A strong selective PpIXfluorescence was found only in the areas of tumor, needed to reach the tumor. However, ALA-PDT is

mostly used in the treatment of tumors at the surfacesdysplasia, or severe inflammation, although a weakPpIX fluorescence was observed in the normal or inof organs (the skin, bladder, and aerodigestive tract).

In such cases, lamps may be as well suited as lasers.flamed areas. With this technique, patients coughedduring inhalation, but the peak expiratory flow did not Nonlaser light sources emit significant fluences of in-

frared radiation together with light useful for PDT.188change. Awadh and Lam66 examined the efficacy ofALA-derived PpIX as a photosensitizer for photodetec- Infrared radiation should be filtered out to avoid hy-

perthermia, although some investigators find that mildtion and PDT of early-stage lung carcinoma in 5 pa-tients with 8 sites of carcinomas in situ after oral ad- hyperthermia (40–42 7C) acts additively or synergisti-

cally with PDT.189,190 To avoid hyperthermia, a fluenceministration of 25–60 mg/kg ALA. They claimed thatALA-derived PpIX fluorescence was poor for selective rate lower than 150 mW/cm2 should be used. Figure

2 shows the emission spectrum of a halogen lampphotodetection of tumors, with diffuse false positivePpIX fluorescence in areas of inflammation or meta- with filters constructed by one of our colleagues, H. B.

Steen (of the Biophysics department at our institution)plasia. However, after light exposure with 630 nm froma KTP-dye laser at a light dose of 200 J/cm2 (using for ALA-PDT, together with the absorption spectra of

PpIX and its photoproducts. It has been reported thatmicrolens or a cylindrical diffuser), complete responsewas achieved in 7 of 8 sites treated, with a follow-up pulsed light may have a deeper penetration into tissue

than continuous wave (CW) light.191 If this is true, theof 1–12 months. Moreover, no skin photosensitivitywas observed. This indicates that systemically admin- effect must be due to saturation of the normal absorb-

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FIGURE 2. This figure shows theabsorption spectra for protoporphyrinIX and photoprotoporphyrin (Porphy-rin Products, Logan, UT) in 10% hu-man serum in phosphate-buffered sa-line and the emission spectra of a dyelaser and a broadband halogen lampwith filters constructed for 5-amino-levulinic acid–based photodynamictherapy.

ers in tissue, mainly melanin and hemoglobin. Ex- tinction coefficient of the sensitizer at the treatmentwavelength, and the fluence rate of the light. Thus,tremely short light pulses would be needed to reach

saturation because the lifetimes of excited states of in the case of ALA-PDT with light within the Soretband of PpIX, one would expect to find O2 depletionthe tissue chromophores are very short.191 Thus, some

investigators find little difference in the efficiency of at a fluence rate of only 5% of that giving O2 deple-tion when applying light at 630 nm. In any case,pulsed light and CW light with respect to PDT effi-

ciency.192,193 surface irradiation would lead to O2 depletion onlyin the upper part of the tissue (which may be good,

Oxygen Depletion during ALA-PDT because it would help save normal skin) because theOxygen is needed in PDT reactions. We have found space irradiance decreases very rapidly with increas-that the PDT efficiency is halved when the concen- ing distances from the surface. Typically, the spacetration of O2 is reduced to 1% (Ç14 mM) from 20% irradiance is halved per 1 mm (at 400 nm) to 3 mmin well-oxygenated tissue, which is similar to what (at 630 nm) down into the tissue.was found for ionizing radiation.194 During PDT theconcentration of O2 in tissue is reduced in two ways:

Choice of Optimal Wavelength for ALA-PDTthrough damage of the vascular system and throughIn most cases of ALA-PDT, light at 630 nm is applied.O2 consumption in the oxidative reactions takingHowever, down to about 2 mm from the surface inplace. Thus, the blood perfusion is a main determi-human skin and muscle tissues as well as in BCC le-nant for the limiting light fluences above which O2

sions, light in the Soret band (410 nm) would give thedepletion occurs. It has been observed that in ALA-largest cell inactivation, whereas at depths exceedingPDT a given exposure at a high fluence rate leads to2 mm, 635 nm light may be optimal (Fig. 3).195 Similarless skin damage than the same exposure given at afindings were obtained by others.196 Basically, thelow fluence rate (Kennedy J C, unpublished data).choice of the optimal wavelength for PDT should beUsually, at clinical doses of the commonly used sen-made on the basis of the appropriate action spectrum.sitizers for i.v. injection, O2 depletion is of concernOne convenient method would be to measure the ac-at fluence rates above 50 mW/cm2 . In the case oftion spectrum of photobleaching of the dye, since thatALA-PDT, however, the PpIX concentration is so lowprocess is caused by generation of singlet oxygen,that significantly higher fluence rates can be usedwhich is also the cytotoxic photoproduct.197 As photo-without any risk of reducing the efficiency by O2

sensitizing photoproducts with an absorption peakdepletion. It should be noted that what one may callaround 670 nm are formed during ALA-PDT, it maythe ‘‘PDT-dose rate’’ is proportional to the product

of the sensitizer concentration in the tissue, the ex- be advantageous to use a broad-band light source with

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FIGURE 3. This figure shows thepenetration depth (d) of light into ahuman hand as a function of the wave-length and the fluorescence excitationspectrum of protoporphyrin IX (PpIX)(lem Å 690 nm) at different depthsbelow the tissue surface from 0 to 3mm and normalized to unity at 635nm, calculated per photo incident onthe tissue by using the fluorescenceexcitation spectrum of PpIX in cells invitro (0.0) and the appropriate valuesof d. The inset shows the PpIX fluo-rescence excitation spectrum in the620–650 nm wavelength region (lem

Å 690 nm), 0, 3, and 6 mm below thetissue surface, determined per photonincident on the tissue surface.

an emission spectrum that also covers part of the ac- Photodegradation Products of PpIXWhen PpIX is exposed to light, several chlorin-typetion spectrum of the photoproducts (Fig. 2).photoproducts are formed.203–207 When proteins arepresent, some of the protein-derived photoproductsDosimetryreact with PpIX to produce secondary PpIX-derivedDosimetry, in relative units, can also be convenientlyphotoproducts. One of the major products is photo-determined by measuring the rate of photobleachingprotoporphyrin, which is itself a good photosensitizerof the sensitizer.197

but also a photolabile molecule.201,208–210 Being a chlo-rine, it has a relatively strong absorption at about 670PHOTODEGRADATION OF PPIXnm,195,201,209 which some of the PDT lamps have beenPpIX is rapidly degraded during ALA-PDT.198–200 Inconstructed to cover.195 However, in most cases theview of this, the real PDT dose isamount of photoprotoporphyrin formed is so smallthat it does not play a major role for ALA-PDT.211

* C(Fet)eFdt,

where C(Fet) is the concentration of sensitizer in tis- MAJOR CURRENT CHALLENGESMuch knowledge has already been obtained about thesue, decreasing as a function of the product of fluence

rate (F), extinction coefficient (e), and time (t). Photo- metabolism and biodistribution of ALA and porphyrinprecursors in the heme biosynthetic pathway. Recentdegradation of PpIX may occur at a low rate even in

the absence of O2 .201,202 During ALA-PDT it is mainly studies have shown a high uptake of ALA by morerapidly proliferating cells. Together with possibly lowthe PpIX present in the upper 0.1 mm of tissue that is

degraded to any significant extent.200 If the concentra- activity of ferrochelatase, this favors porphyrin accu-mulation by tumor cells, thus providing a biologic ra-tion of PpIX in the skin and other tissues overlying a

tumor is so low that most of it is photodegraded before tionale for the clinical use of ALA-based diagnosis andPDT. Clinical applications of topical ALA-PDT haveirrepairable PDT-induced damage is caused, photo-

bleaching can be taken advantage of. In such cases already achieved promising results, indicating that thismodality is an effective and practical method for thethere is no upper limit to the light exposures one can

apply and it is possible to eradicate tumors, which treatment of superficial benign and malignant dis-eases of the skin and internal hollow organs.212 Futureusually contain significantly higher concentrations of

sensitizer than the normal surrounding tissues, with- research should be intensified to determine whatmechanisms are responsible for recurrence of someout any unacceptable damage to normal tissue.199

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skin tumors treated with ALA-PDT, for wide individualvariation (among cells, tissues, and patients) of theconcentration and localization of ALA-derived PpIX,and for poor gastrointestinal tumor selectivity. More-over, the parameters affecting ALA-based diagnosisand PDT must be optimized, and the efficacy of themodality with a long term follow-up has yet to becompared with those of conventional therapies in con-trolled clinical trials.

Topical ALA-PDT for Skin DisordersClearly, patients with certain categories of skin lesionsdo benefit from ALA-PDT. These are (1) patients withlesions that if resected would result in significant cos-metic or functional impairment (i.e., lesions in mid-face, including the nose and the perioral and periocu-lar areas; ear lesions; etc.), (2) patients with multicen-tric lesions, (3) patients who have failed previoustherapy, and (4) patients who are medically unfit toundergo surgery and/or general anesthesia (e.g., re- FIGURE 4. This figure shows the concentration of 5-aminolevulinic acidcent myocardial infarction). Currently, however, the (ALA) and ALA-ester derivatives needed to produce half of the maximumtechniques of topical ALA-PDT for skin disorders have protoporphyrin IX accumulation in WiDr cells. The bars show standardnot been optimally established. In particular, inhomo- deviation based on two sets of experiments in triplicate.geneous distribution or lack of selective accumulationof ALA-derived PpIX in nodular and infiltrating skin

3) Determining the optimal time for topical ALA ap-tumors (e.g., BCC and SCC) suggests that topical ALAplication would allow sufficient ALA penetrationapplication with the current delivery procedure mayand ALA-derived porphyrin production in wholenot be a reliable regimen for ALA-PDT treatment oflesions, providing a clinical practical conveniencesuch diseases.for both physicians and patients.The efficacy of ALA-PDT may be improved by the

4) Direct intralesional injection of ALA could be ad-following approaches:ministered in some cases.

1) Certain agents may improve ALA penetration into 5) Systemic administration (oral/i.v.) of ALA coulddeep lesions without reducing selectivity. The lead to a more homogenous tissue accumulationchoice of solvents may be an important factor in of ALA-derived PpIX.determining the properties of the enhancer. Sev- 6) Simpler, cheaper, and more efficient light deliveryeral physical methods may also enhance ALA pen- systems should be constructed with respect to op-etration, such as tape-stripping, partial curettage timal wavelengths of photoactivating light for bothof lesions, ultrasound, microwave irradiation, and PpIX and its chlorin-type of photoproducts.iontophoresis. 7) The photobleaching property of ALA-derived PpIX

2) Potent inhibitors of ferrochelatase and protopor- can be used to increase the selectivity of the ALA-phyrinogen oxidases and modulators of heme and PDT effect.chlorophyll biosynthetic pathway could be used 8) Intermittent applications of activating light couldto manipulate cellular biochemistry (including in- increase the ALA-PDT efficiency.tracellular iron metabolism) for enhancing the 9) Repeated ALA-PDT treatments may be advanta-production of ALA-derived porphyrins. Preclinical geous because this modality has no side effects orstudies have already shown that several com- cumulative toxicity.pounds, such as DMSO, EDTA, DFO, 2-allyl-2-iso- 10) A better understanding of light distribution in tis-propylacetamide, 1,10-Phenanthroline, and 1,2- sue and improved dosimetry procedures will leaddiethyl-3-hydroxypyridin-4-one, have potential to improvements of ALA-PDT.213

for increasing porphyrin accumulation from ALA.In addition, some cell-stimulating compounds, PDT with ALA Ester Derivatives

Topical ALA-PDT is, to some extent, restricted by thesuch as lectin, may help cells and tumors to accu-mulate ALA-derived PpIX selectively. rate of uptake of the hydrophilic ALA by neoplastic

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cells and/or its poor diffusion through the skin lesions,particularly in the case of thick lesions. ALA ester de-rivatives would show better biologic availability in thecutaneous lesions due to their lipophilic character.Such ALA derivatives are deesterified by esterase incells and tissues. We therefore studied several ALA es-ter derivatives (ALA esterified with C1 –C3 and C6 –C8

chained aliphatic alcohols), and found that in bothWiDr and NHIK human carcinoma cell lines in vitro,esterification of ALA with the long chain (C6 –C8) alco-hols produced ALA-derived PpIX more efficiently thandid nonesterified ALA (Fig. 4). Short chain ALA esters(C1 –C3) were less efficient than ALA in inducing ALA-derived PpIX. Similar results have also been recentlyreported.214 The PpIX induced from nonesterified oresterified ALA was found to be equally efficient in sen-sitizing the tumor cells to photoinactivation.22 In ani-mal studies, by means of a fiberoptic point monitoringsystem and fluorescence microscopy, the ALA esterswith the short chain alcohols were found to be deester-ified and converted into porphyrins in the normal skinof mice. The porphyrin fluorescence produced fromthe ALA esters was similar or stronger than that in-duced by ALA (in contrast with results in vitro) (Peng etal., unpublished data). Moreover, preliminary studieshave shown that topical ALA methylester-PDT resultedin a stronger growth inhibition of WiDr tumor xeno-grafts in vivo than topical ALA-PDT (Peng et al., un-published data). In clinical trials with nodular BCClesions, the porphyrin fluorescence derived from ALAesters with the short or long chain alcohols was found

FIGURE 5. Fluorescence photomicrographs of human rectal papillaryto be stronger and a more homogenously distributedvillous adenomas sampled 44 hours after intravenous injection of 2 mg/and to have a better selectivity than that induced bykg Photofrin (A) and 4.5 hours after oral administration of 60 mg/kg 5-ALA (Peng et al., unpublished data). It is noteworthyaminolevulinic acid (ALA) (B). The fluorescence of Photofrin is mainlythat topical ALA-ester-PDT leads to significantly lessdistributed in the stroma of the tumor tissue, whereas the fluorescencepain during or after light exposure than ALA-PDT. Theof ALA-induced porphyrins is almost entirely localized in the tumor cells.reasons for this are not fully understood. Because it

results in less pain and higher selectivity with bettertherapeutic effectiveness expected, ALA methylester isused as a preferable drug for topical PDT at the Norwe- ALA-derived PpIX is cleared from the body within 24–

48 hours after systemic ALA administration. Thisgian Radium Hospital. Overall, the ester derivatives ofALA may have advantages over nonesterified ALA in would reduce or avoid the risk of prolonged skin pho-

totoxicity. Our previous studies have shown that effi-topical ALA-PDT of superficial lesions. Furthermore,the high selectivity of PpIX induced by ALA esters may cient eradication of tumor by PDT requires destruction

of both cellular components and vascular stroma ofhave potentials for clinical diagnostic purposes. How-ever, more controlled clinical work is needed; in par- tumor.215,216 Because PpIX synthesized endogenously

from ALA localizes within tumor cells and Photofrinticular, the pharmacokinetics and toxicity of ALA es-ters should be carefully studied. distributes mainly in vascular stroma of tumors (Fig.

5), PDT with a mixture of ALA (at a therapeutic dose)and Photofrin (at a low dose that would reduce orPDT Using a Combination of ALA and Photofrin

The major side effect associated with Photofrin-based avoid the risk of skin photosensitivity) may destroyboth neoplastic cells and vascular stroma of tumorPDT is the prolonged risk of skin photosensitivity. This

restricts clinical PDT application to a considerable ex- tissue. Thus, we combined ALA with Photofrin in thetreatment of human WiDr tumor xenografts. The dosetent. The main advantage of using ALA-PDT is that

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of ALA applied was 250 mg/kg, and that of Photofrin Furthermore, such fluorescence detection in situ maybe used to estimate the optimal time for light activa-was 1 mg/kg, a dose 5–20 times lower than therapeutic

doses for such tumor xenografts and one that does tion and the rate of PpIX photobleaching after thera-peutic light irradiation, and may also be used to pre-not induce any skin photosensitivity. PDT with such a

combination inhibited the growth of the tumors more dict the outcome of PDT. The correlation of the fluo-rescence values obtained by such fluorescenceefficiently than PDT with ALA (250 mg/kg) or Photofrin

(5 mg/kg) alone (Peng et al., unpublished data). These measurements with actual ALA-derived PpIX levels isrequired, as the PDT effect depends, to some extent,preliminary studies strongly suggest that the combina-

tion of ALA and Photofrin not only synergistically en- on the tissue concentration of photosensitizer.177,224

Furthermore, such macroscopic fluorescence mea-hances PDT efficiency of tumor but also avoids therisk of photofrin-induced skin phototoxicity. surements may not necessarily agree with the micro-

scopically time-dependent intracellular/extracellularlocalization patterns of ALA-derived PpIX.ALA-PDT for Superficial Lesions of Internal

Hollow OrgansIt is generally accepted that PDT has a curative effect

Other Potential Uses for ALA-PDTon small superficial lesions, probably mainly due to aAttractive possibilities exist for the use of ALA to detectsufficient light penetration of such small tissue vol-and treat malignant cells in blood, as highly preferen-umes. Preferential accumulation of ALA-derived PpIXtial accumulation of ALA-derived PpIX has been shownin the mucosal lesions of the aerodigestive tract, theto occur in the circulating transformed cells7,127,225

genitourinary tract, the bronchial tree, and, to a much(Peng et al., unpublished data). Thus, flow cytometrylesser extent, the submucosal and muscle layers (inof blood or marrow cells of a cancer patient incubatedcontrast with HpD and Photofrin, which distributewith ALA in vitro may permit detection of very lowmainly in the submucosal vascular stroma) allows se-concentrations of certain types of malignant cells.lective destruction by PDT of the small epithelial pre-Subsequently, one may hope that the malignant cellscancerous and cancerous lesions of the hollow organscan be selectively killed by light exposure before auto-with low risk of damage to deeper layers. The tumortransplantation of the blood and marrow. In addition,selectivity of ALA-derived PpIX may be improved bythe modality may have potentials for photoinactiva-fractionated ALA administration8,217,218 or by the use oftion of virus in blood products and parasitized erythro-liposome-encapsulated ALA.219 In addition, ALA-PDTcytes. ALA in combination with light may also be usedmay be used as an intraoperative adjuvant modalityas both a diagnostic and a therapeutic means of car-to destroy residual tumor cells after surgical debulkingdiovascular application.36

of the tumor, because ALA-derived PpIX localizes inindividual malignant cells rather than in tissue stroma.

REFERENCESALA-Derived PpIX Fluorescence for Detection of Tumor,1. Leibovici L, Schoenfeld N, Yehoshua HA, Mamet R, Rakow-

Estimation of Optimal Time for Light Activation, and ski E, Shindel A, et al. Activity of porphobilinogen deaminasePrediction of PDT Response in peripheral blood mononuclear cells of patients with met-A preferential distribution of ALA-derived porphyrins astatic cancer. Cancer 1988;62:2297–300.

2. Schoenfeld N, Epstein O, Lahav M, Mamet R, Shaklai M,in tumor cells provides the possibility of in situ detec-Atsmon A. The heme biosynthetic pathway in lymphocytestion of the porphyrin fluorescence in the superficialof patients with malignant lymphoproliferative disorders.

transformed epithelial cells of the skin and internal Cancer Lett 1988;43:43–8.hollow organs by means of fiberoptic point monitoring 3. Kondo M, Hirota N, Takaoka T, Kajiwara M. Heme-biosyn-systems or of fluorescence imaging systems.220,221 Such thetic enzyme activities and porphyrin accumulation in nor-

mal liver and hepatoma cell line of rats. Cell Biol Toxicola procedure can be performed noninvasively in vivo1993;9:95–105.with immediate results and can also be used for phar-

4. Rubino GF, Rasetti L. Porphyrin metabolism in human neo-macokinetic studies.83,220–223 Topical and local internalplastic tissues. Panminerva Med 1966;8:290–2.

administration of ALA may be used for such diagnostic 5. Dailey HA, Smith A. Differential interaction of porphyrinspurposes because intravesical, intrauterine, and inhal- used in photoradiation therapy with ferrochelatase. Biochem

J 1984;223:441–5.ant administrations do not produce generalized cuta-6. Smith A. Mechanisms of toxicity of photoactivated artificialneous photosensitivity. Currently, promising data are

porphyrins: role of porphyrin-protein interactions. Ann N Yavailable concerning diagnosis of early stages of blad-Acad Sci 1987;514:309–22.

der carcinoma. ALA ester derivatives may be more 7. El-Sharabasy MMH, El-Wassel AM, Hafez MM, Salim SA.suitable for such fluorescence detection because they Porphyrin metabolism in some malignant diseases. Br J Can-

cer 1992;65:409–12.appear to induce PpIX with better tumor selectivity.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


8. 23. Peng Q, Warloe T, Moan J, Heyerdahl H, Steen HB, Gierckskyvan Hillegersberg R, van den Berg JW, Kort WJ, Terpstra OT,K-E, Nesland JM. ALA derivative-induced protoporphyrin IXWilson JH. Selective accumulation of endogenously pro-build-up and distribution in human nodular basal cell carci-duced porphyrins in a liver metastasis model in rats. Gastro-noma. Photochem Photobiol 1995;61:82S.enterology 1992;103:647–51.

24. Peng Q, Moan J, Warloe T, Iani V, Steen HB, Bjørseth A,9. Kennedy JC, Pottier RH, Pross DC. Photodynamic therapyNesland JM. Build-up of esterified aminolevulinic-acid-de-with endogenous protoporphyrin IX: basic principle andrivative-induced porphyrin fluorescence in normal mousepresent clinical experience. J Photochem Photobiol Bskin. J Photochem Photobiol B 1996;34:95–6.1990;6:143–8.

25. Rebeiz CA, Reddy KN, Nandihalli UB, Velu J. Tetrapyrrole-10. Kennedy JC, Pottier RH. Endogenous protoporphyrin IX: adependent photodynamic herbicides. Photochem Photobiolclinical useful photosensitizer for photodynamic therapy. J1990;52:1099–1117.Photochem Photobiol B 1992;14:275–92.

26. Wilson JHP, van Hillegersberg R, van den Berg JWO, Kort11. Wolf P, Rieger E, Kerl H. Topical photodynamic therapy withWJ, Terpstra OT. Photodynamic therapy for gastrointestinalendogenous porphyrins after application of 5-aminolevu-tumors. Scand J Gastroenterol 1991;26(Suppl 188):20–5.linic acid. J Am Acad Dermatol 1993;28:17–21.

27. Lui H, Anderson RR. Photodynamic therapy in dermatology.12. Cairnduff F, Stringer MR, Hudson EJ, Ash DV, Brown SB.Arch Dermatol 1992;128:1631–6.Superficial photodynamic therapy with topical 5-aminolae-

28. Kennedy JC, Pross DC, Pottier RH. Photodynamic therapy ofvulinic acid for superficial primary and secondary skin can-carcinoma using endogenous protoporphyrin IX induced bycer. Br J Cancer 1994;69:605–8.topical 5-aminolevulinic acid. In: Jung EG, Holick MF. Biologic13. Svanberg K, Andersson T, Killander D, Wang I, Stenram U,effects of light. Berlin: Walter de Gruyter, 1993:372–86.Ansersson-Engels S, et al. Photodynamic therapy of non-

29. Batlle AM del C. Porphyrins, porphyrias, cancer and photo-melanoma malignant tumors of the skin using topical d-dynamic therapy: a model for carcinogenesis. J Photochemamino-levulinic acid sensitization and laser irradiation. BrPhotobiol B 1993;20:5–22.J Dermatol 1994;130:743–51.

30. Bown SG. Photodynamic therapy in gastroenterology: cur-14. Warloe T, Peng Q, Heyerdahl H, Moan J, Steen HB, Gierckskyrent status and future prospects. Endoscopy 1993;25(Suppl):KE. Photodynamic therapy with 5-aminolevulinic acid in-683–685.duced porphyrins and DMSO/EDTA for basal cell carci-

31. van Hillegersberg R, Kort WJ, Wilson JHP. Current status ofnoma. In: Cortese DA, editor. 5th International Photody-photodynamic therapy in oncology. Drugs 1994;48:510–27.namic Association Biennial Meeting. Proc SPIE 1995;2371:

32. Roberts DJH, Cairnduff F. Photodynamic therapy of primary226–35.skin cancer: a review. Br J Plast Surg 1995;48:360–70.15. Calzavara-Pinton PG. Repetitive photodynamic therapy with

33. Wolf P, Kerl H. Photodynamic therapy with 5-aminolevulinictopical delta-aminolevulinic acid as an appropriate ap-acid: a promising concept for the treatment of cutaneousproach to the route treatment of superficial non-melanomatumors. Dermatology 1995;190:183–5.skin tumors. J Photochem Photobiol B 1995;29:53–7.

34. Stables GI, Ash DV. Antitumour treatment: photodynamic16. Regula J, MacRobert AJ, Gorchein A, Buonaccorsi GA,therapy. Cancer Treat Rev 1995;21:311–23.Thorpe SM, Spencer GM, et al. Photosensitisation and pho-

35. Pottier RH, Kennedy CJ. Photodynamic therapy with 5-todynamic therapy of oesophageal, duodenal, and colorectalaminolevulinic acid: basic principles and application. Proctumors using 5 aminolaevulinic acid induced protoporphy-SPIE 1996;2625:2–10.rin IX: a pilot study. Gut 1995;36:67–75.

36. Nyamekye I. Vascular and other non-tumor application of17. Fromm D, Kessel D, Webber J. Feasibility of photodynamic

photodynamic therapy. Lasers Med Sci 1996;11:3–10.therapy using endogenous photosensitization for colon can-

37. Peng Q, Berg K, Moan J, Kongshaug M, Nesland JM. 5-cer. Arch Surg 1996;131:667–9.

Aminolevulinic acid-based photodynamic therapy: princi-18. Kriegmair M, Baumgartner R, Knuechel R, Stepp H, Hofs- ples and experimental research. Photochem Photobiol

tadter F, Hofstetter A. Detection of early bladder cancer by 5- 1997;65:235–251.aminolevulinic acid induced porphyrin fluorescence. J Urol 38. May BK, Bawden MJ. Control of heme biosynthesis in ani-1996;155:105–10. mals [review]. Semin Hematol 1989;26:150–6.

19. Huber RM, Gamarra F, Leberig A, Stepp H, Rick K, Baumgar- 39. Scotto AW, Chang LF, Beattie DS. The characterization andtner R. Inhaled 5-aminolevulinic acid (ALA) for photody- submitochondrial localization of delta-aminolevulinic acidnamic diagnosis and early detection of bronchial tumors: synthase and an associated amidase in rat liver mitochon-first experience in patients. In: Abstract book of 6th IPA dria using an improved assay for both enzymes. J Biol Chemmeeting, 1996. 1983;258:81–90.

20. Goff BA, Bachor R, Kollias N, Hasan T. Effects of photody- 40. Xu W, Kozak CA, Desnick RJ. Uroporphyrinogen-III syn-namic therapy with topical application of 5-aminolevulinic thase, molecular cloning, nucleotide sequence, expressionacid on normal skin of hairless guinea pigs. J Photochem of a mouse full-length cDNA, and its localization on mousePhotobiol B 1992;15:239–51. chromosome 7. Genomics 1995;26:556–62.

21. Warloe T, Peng Q, Steen HB, Giercksky K-E. Localization of 41. Elder GH, Evans JO. Evidence that the coproporphyrinogenporphyrins in human basal cell carcinoma and normal skin oxidase activity of rat liver is situated in the intermembranetissue induced by topical application of 5-aminolevulinic space of mitochondria. Biochem J 1978;172:345–7.acid. In: Spinelli P, Fante MD, Marchesini R. Photodynamic 42. Grandchamp B, Phung N, Nordmann Y. The mitochondrialtherapy and biomedical lasers. Amsterdam: Elsevier Science localization of coproporphyrinogen III oxidase. Biochem JPublishers B. V., 1992:454–8. 1978;176:97–102.

22. Gaullier JM, Berg K, Peng Q, Anholt H, Selbo PK, Ma LM, et 43. Ferreira GC, Andrew TL, Karr SW, Dailey HA. Organization ofal. The use of esters of 5-aminolevulinic acid to improve the terminal two enzymes of the heme biosynthetic pathway:photodynamic therapy on cells in culture. Cancer Res. 1997; orientation of protoporphyrinogen oxidase and evidence for a

membrane complex. J Biol Chem 1988;263:3835–9.57:1481–6.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


44. Malik Z. Photodynamic therapy of human skin tumors usingMoore MR, McColl KEL, Rimigton C, Goldberg A. Disorderstopical application of 5-aminolevulinic acid, DMSO andof porphyrin metabolism. New York: Plenum Press, 1987.EDTA. In: Brault D, Jori G, Moan J, Ehrenberg B. Photody-45. Bottomley SS, Muller-Eberhard U. Pathophysiology of hemenamic therapy of cancer II. Proc SPIE 1995;2325:100–5.synthesis [review]. Semin Hematol 1988;25:282–302.

62. Morton CA, Whitehurst C, Moseley H, Moore JV, Mackie46. Rossi E, Attwood PV, Garcia-Webb P, Costin KA. InhibitionRM. Development of an alternative light source to lasers forof human lymphocyte ferrochelatase activity by hemin. Bio-photodynamic therapy. 1. Clinical evaluation in the treat-chim Biophys Acta 1990;1038:375–81.ment of pre-malignant non-melanoma skin cancer. Lasers47. Wolfson SJ, Bartczak A, Bloomer JR. Effect of endogenousMed Sci 1995;10:165–71.heme generation on delta-aminolevulinic acid synthase activ-

63. Fritsch C, Verwohlt B, Bolsen K, Ruzicka T, Goerz G. Kineticsity in rat liver mitochondria. J Biol Chem 1979;254:3543–6.of erythrocyte and plasma porphyrins and excretion of delta-48. Hamilton JW, Bement WJ, Sinclair PR, Sinclair JF, Alcedo JA,aminolevulinic acid, porphobilinogen and porphyrins in pa-Wetterhahn KE. Heme regulates hepatic 5-aminolevulinatetients treated with topical delta-aminolevulinic acid photo-synthase mRNA expression by decreasing mRNA half-lifedynamic therapy. 6th IPA meeting, 1996. Abstract book.and not by altering its rate of transcription. Arch Biochem

64. Fijan S, Honigsmann H, Ortel B. Photodynamic therapy ofBiophys 1991;289:387–92.epithelial skin tumours using delta-aminolevulinic acid and49. Drew PD, Ades IZ. Regulation of the stability of chickendesferrioxamine. Br J Dermatol 1995;133:282–8.embryo liver delta-aminolevulinate synthase mRNA by he-

65. Peng Q, Warloe T, Moan J, Heyerdahl H, Steen HB, Neslandmin. Biochem Biophys Res Commun 1989;162:102–7.JM, et al. Distribution of 5-aminolevulinic acid–induced50. Cable EE, Pepe JA, Karamitsios NC, Lambrecht RW, Bonkov-porphyrins in noduloulcerative basal cell carcinoma. Pho-sky HL. Differential effects of metalloporphyrins on messen-tochem Photobiol 1995;62:906–13.ger RNA levels of delta-aminolevulinate synthase and heme

66. Awadh N, Lam S. Photodetection and PDT for early lungoxygenase: studies in cultured chick embryo liver cells. Jcancer using aminolevulinic acid. 6th IPA meeting, 1996.Clin Invest 1994;94:649–54.Abstract book.51. Yamamoto M, Kure S, Engel JD, Hiraga K. Structure, turn-

67. Scott JJ. The metabolism of d-aminolevulinic acid. In: Wols-over, and heme-mediated suppression of the level of mRNAtenholme GEW, Millar ECP. Ciba Foundation Symposiumencoding rat liver delta-aminolevulinate synthase. J Biolon Porphyrin Biosynthesis and Metabolism. London, J. andChem 1988;263:15973–9.A. Churchill, Ltd, 1955:43–62.52. May BK, Dogra SC, Sadlon TJ, Bhasker CR, Cox TC, Bot-

68. Shimizu Y, Ida S, Naruto H, Urata G. Excretion of porphyrinstomley SS. Molecular regulation of heme biosynthesis inin urine and bile after the administration of delta-aminolev-higher vertebrates [review]. Prog Nucleic Acid Res Mol Biolulinic acid. J Lab Clin Med 1978;92:795–802.1995;51:1–51.

69. Dowdle E, Mustard P, Spong N, Eales L. The metabolism of53. Borthwick IA, Srivastava G, Day AR, Pirola BA, Snoswell MA,(5-14C)-aminolevulinic acid in normal and porphyric humanMay BK, et al. Complete nucleotide sequence of hepatic 5-subjects. Clin Sci 1968;34:233–51.aminolaevulinate synthase precursor. Eur J Biochem 1985;

70. Meyer US, Strand LJ, Doss M, Rees AC, Marver HS. Intermittent150:481–4.acute porphyria-demonstration of a genetic defect in porpho-54. Yamauchi K, Hayashi N, Kikuchi G. Translocation of delta-bilinogen metabolism. N Engl J Med 1972;286:1277–82.aminolevulinate synthase from the cytosol to the mitochon-

71. Mustajoki P, Timonen K, Gorchein A, Seppalainen AM, Mati-dria and its regulation by hemin in the rat liver. J Biol Chemkainen E, Tenhunen R. Sustained high plasma 5-aminolae-1980;255:1746–51.vulinic acid concentration in a volunteer, no porphyric55. Hayashi N, Watanabe N, Kikuchi G. Inhibition by hemin ofsymptoms. Eur J Clin Invest 1992;22:407–11.in vitro translocation of chicken liver delta-aminolevulinate

72. Gorchein A, Webber R. d-Aminolevulinic acid in plasma, cere-synthase into mitochondria. Biochem Biophys Res Communbrospinal fluid, saliva and erythrocytes: studies in normal,1983;115:700–6.uraemic and porphyric subjects. Clin Sci 1987;72:103–12.56. Igarashi J, Hayashi N, Kikuchi G. Delta-aminolevulinate syn-

73. McGillion FB, Thompson GG, Moore MR, Goldberg A. Thethetases in the liver cytosol fraction and mitochondria ofpassage of d-aminolevulinic acid across the blood-brain bar-mice treated with allylisopropylacetamide and 3,5-dicarbe-rier of the rat. Biochem Pharmacol 1974;23:472–4.thoxyl-1,4-dihydrocollidine. J Biochem (Tokyo) 1976;80:

1091–9. 74. Gabriel F, Juknat AA, del AM, Batlle C. Porphyrinogenesisin rat cerebellum: effect of high d-aminolevulinic acid con-57. Berry JP. The role of lysosomes in the selective concentrationcentration. Gen Pharmac 1994;25:761–6.of mineral elements: a microanalytical study. Cell Mol Biol

75. Juknat AA, Kotler ML, del AM, Batlle C. High d-aminolevu-1996;42:395–411.linic acid uptake in rat cerebral cortex: effect on porphyrin58. Lathrop JT, Timko MP. Regulation by heme of mitochondrialbiosynthesis. Comp Biochem Physiol 1995;111C:143–150.protein transport through a conserved amino acid motif.

76. Mustajoki P, Koskelo P. Hereditary hepatic porphyrias inScience 1993;259:522–5.Finland. Acta Med Scand 1976;200:171–8.59. Melefors O, Goossen B, Johansson HE, Stripecke R, Gray

77. Dagg JH, Goldberg A, Lochhead A, Smith JA. The relationshipNK, Hentze MW. Translational control of 5-aminolevulinatesynthase mRNA by iron-responsive elements in erythroid of lead poisoning to acute intermittent porphyria. Q J Med

1965;34:163–75.cells. J Biol Chem 1993;268:5974–8.60. 78. Mitchell G, Larochelle J, Lambert M, Michaud J, Grenier A,Peng Q, Warloe T, Moan J, Steen H, Giercksky KE, Nesland

JM. Localization of ALA-induced porphyrins in normal and Ogier H, et al. Neurologic crises in hereditary tyrosinemia.N Engl J Med 1990;322:432–7.malignant tissues of mice, dogs and patients. Conference

on photosensitization and photochemotherapy of cancer, 79. Lofgren LA, Ronn AM, Nouri M, Lee CJ, Yoo D, Steinberg BM.Oslo, March 16–17, 1993. Abstract book, pp. S4. Efficacy of intravenous d-aminolevulinic acid photodynamic

61. Orenstein A, Kostenich G, Tsur H, Roitman L, Ehrenberg B, therapy on rabbit papillomas. Br J Cancer 1995;72:857–64.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


80. 102.Henderson BW, Vaughan L, Bellnier DA, van Leengoed H, Dougherty TJ. Photosensitizers: therapy and detection ofJohnson PG, Oseroff AR. Photosensitization of murine tu- malignant tumors. Photochem Photobiol 1987;45:879–89.mor, vasculature and skin by using 5-aminolevulinic acid– 103. Manyak MJ, Russo A, Smith PD, Glatstein E. Photodynamicinduced porphyrin. Photochem Photobiol 1995;62:780–9. therapy. J Clin Oncol 1988;6:380–91.

81. Webber J, Kessel D, Fromm D. Plasma levels of protoporphy- 104. Dougherty TJ, Marcus SL. Photodynamic therapy. Eur J Can-rin IX in humans after oral administration of 5-aminolevu- cer 1992;28A:1734–42.linic acid. J Photochem Photobiol B 1997;37:151–3. 105. Pass HI. Photodynamic therapy in oncology: mechanisms

82. Egger NG, Motamedi M, Pow-Sang M, Orihuela E, Anderson and clinical use. J Natl Cancer Inst 1993;85:443–56.KE. Accumulation of porphyrins in plasma and tissues of 106. Dougherty TJ. Photodynamic therapy. Photochem Photobioldogs after d-aminolevulinic acid administration: implica- 1993;58:895–900.tions for photodynamic therapy. Pharmacology 1996;52: 107. Fisher AMR, Murphree L, Gomer CJ. Clinical and preclinical362–70. photodynamic therapy. Lasers Surg Med 1995;17:2–31.

83. Pottier RH, Chow YFA, LaPlante JP, Truscott TG, Kennedy 108. Schuitmaker JJ, Baas P, van Leengoed HLLM, van der Meu-JC, Beiner LA. Non-invasive technique for obtaining fluo- len FW, Star WM, van Zandwijk N. Photodynamic therapy:rescence excitation and emission spectra in vivo. Photochem a promising new modality for the treatment of cancer. JPhotobiol 1986;44:679–87. Photochem Photobiol B 1996;34:3–12.

84. Peng Q, Moan J, Warloe T, Nesland JM, Rimington C. Distri- 109. Sacchini V, Melloni E, Marchesini R, Luini A, Bandieramontebution and photosensitizing efficiency of porphyrins in- G, Spinelli P, et al. Preliminary clinical studies with PDT byduced by application of exogenous 5-aminolevulinic acid in topical TPPS administration in neoplastic skin lesions. La-mice bearing mammary carcinoma. Int J Cancer 1992; sers Surg Med 1987;7:6–11.52:433–43. 110. Santoro O, Bandieramonte G, Melloni E, Marchesini R, Zun-

85. Peng Q, Evensen JF, Rimington C, Moan J. A comparison of ino F, Lepera P, Palo GD. Photodynamic therapy by topicaldifferent photosensitizing dyes with respect to uptake by meso-tetraphenylporphinesulfonate tetrasodium salt ad-C3H-tumors and tissues of mice. Cancer Lett 1987;36:1–10. ministration in superficial basal cell carcinoma. Cancer Res

86. Berlin NI, Neuberger A, Scott JJ. The metabolism of d-amino- 1990;50:4501–3.levulinic acid. 1. Normal pathway, studied with the aid of 111. Wolf P, Kerl H. Photodynamic therapy in a patient with xero-15N. Biochem J 1956;64:80–90. derma pigmentosum. Lancet 1991;337:1613–4.

87. Berlin NI, Neuberger A, Scott JJ. The metabolism of d-amino- 112. Gregory RO, Goldman L. Application of photodynamic ther-levulinic acid. 2. Normal pathway, studied with the aid of apy in plastic surgery. Lasers Surg Med 1986;6:62–6.14C. Biochem J 1956;64:90–100. 113. Orenstein A, Kostenich G, Tsur H, Kogan L, Malik Z. Temper-

88. Jarrett A, Rimington C, Willoughby DA. d-Aminolevulinic ature monitoring during photodynamic therapy of skin tu-acid and porphyria. Lancet 1956;i:125–6. mors with topical 5-aminolevulinic acid application. Cancer

89. Wooten RS, Smith KC, Ahlquist DA, Muller AA, Balm RK. Lett 1995;93:227–32.Prospective study of cutaneous phototoxicity after systemic 114. Warloe T, Peng Q, Moan J, Qvist HL, Giercksky KE. Photo-hematoporphyrin derivative. Lasers Surg Med 1988;8:294– chemotherapy of multiple basal cell carcinoma with endoge-300. nous porphyrins induced by topical application of 5-amino-

90. Dougherty T, Cooper MT, Many TS. Cutaneous phototoxic levulinic acid. In: Spinelli P, Fante MD, Marchesini R. Photo-occurrences in patients receiving Photofrin. Lasers Surg Med dynamic therapy and biomedical lasers. Amsterdam:1990;10:485–8. Elsevier Science Publishers B.V., 1992:449–53.

91. Miller SJ. Biology of basal cell carcinoma. J Am Acad Derma- 115. Svanberg K, Andersson T, Killander D. Photodynamic ther-tol 1991;24:161–75. apy of human skin malignancies and laser-induced fluores-

92. Preston DS, Stern RS. Nonmelanoma cancers of the skin. N cence diagnostics utilizing Photofrin and delta-aminolevu-Engl J Med 1992;327:1649–62. linic acid. In: Spinelli P, Fante MD, Marchesini R. Photody-

93. Giles GG, Marks R, Foley P. Incidence of non-melanocytic namic therapy and biomedical lasers. Amsterdam: Elsevierskin cancer treated in Australia. Br Med J 1088;296:13–7. Science Publishers B.V., 1992:436–40.

94. Davies DM. Malignant skin conditions. Br Med J 1984; 116. Lui H, Salasche S, Ariz T, Kollias N, Wimberly J, et al. Photo-290:1190–4. dynamic therapy of nonmelanoma skin cancer with topical

95. Roenigk RK, Ratz JL, Bailin PL, Wheeland RG. Trends in aminolevulinic acid: a clinical histologic study. Arch Derma-the presentation and treatment of basal cell carcinomas. J tol 1995;131:737–8.Dermatol Surg Oncol 1986;12:860–5. 117. Oseroff AR, Babich D, Blaird-Wagner D, Hryhorenko E, Mor-

96. Emmett AJ. Surgical analysis and biological behaviour of gan J, Rittenhouse-Diakun K. ALA-PDT in dermatology: re-2277 basal cell carcinomas. Aust N Z J Surg 1990;60:855–63. sults and mechanisms. Photochem Photobiol 1996;63:89S.

97. Brady LW. External irradiation of epithelial skin cancer. Int 118. Martin A, Tope WD, Grevelink JM, Starr JC, Fewkes JL, FlotteJ Radiat Oncol Biol Phys 1990;19:491–2. TJ, et al. Lack of selectivity of protoporphyrin IX fluorescence

98. Lovett RD, Perez CA, Shapiro SJ, Garcia DM. External irradia- for basal cell carcinoma after topical application of 5-amino-levulinic acid: implications for photodynamic treatment.tion of epithelial skin cancer. Int J Radiat Oncol Biol Phys

1990;19:235–42. Arch Dermatol Res 1995;287:665–74.99. 119.Dougherty TJ. Photosensitization of malignant tumors. Szeimies R-M, Sassy T, Landthaler M. Penetration potency

Semin Surg Oncol 1986;2:24–37. of topical applied d-aminolevulinic acid for photodynamictherapy of basal cell carcinoma. Photochem Photobiol 1994;100. Berns MW, Wile AG. Hematoporphyrin phototherapy of can-59:73–6.cer. Radiother Oncol 1986;7:233–40.

120.101. McCaughan JS. Overview of experiences with photodynamic Stoughton RB, Fritsch WC. Influence of dimethylsulfoxide(DMSO) on human percutaneous absorption. Arch Dermatoltherapy for malignancy in 192 patients. Photochem Pho-

tobiol 1987;46:903–9. 1964;90:512–7.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


121. ton and Hamilton. In: Kessel D, Dougherty TJ. PorphyrinRoberts DJH, Stables GI, Ash DV, Brown SB. Distribution ofphotosensitization. New York: Plenum Press, 1983:53–62.protoporphyrin IX in Bowen’s disease and basal cell carcino-

139. Tse DT, Kersten RC, Andersson RL. Hematoporphyrin deriv-mas treated with topical 5-aminolevulinic acid. Proc SPIEative photoradiation therapy in managing nevoid basal cell1995;2371:490–4.carcinoma syndrome. Arch Ophthalmol 1984;102:990–4.122. Tope WD, Kollias N, Ross EV, Martin A, Deutsch TF, Ander-

140. Tomio L, Calzavara F, Zorat PL, Corti L, Polico C, Reddi E, etson RR. Oral delta-aminolevulinic acid for protoporphyrinal. Photoradiation therapy for cutaneous and subcutaneousIX fluorescence in basal cell carcinoma. 6th IPA meeting,malignant tumors using hematoporphyrin. In: Doiron DR,1996. Abstract book.Gomer CJ. Porphyrin localization and treatment of tumor.123. Karrer S, Szeimies R-M, Hohenleutner U, Heine A, Land-New York: Alan R. Liss, Inc., 1984:829–40.thaler M. Unilateral localized basaliomatosis: treatment with

141. Cai WM, Yang Y, Zhang NW, Xie JG, Zhang X, Fan XJ, et al.topical photodynamic therapy after application of 5-amino-Photodynamic therapy in the management of cancer: anlevulinic acid. Dermatology 1995;190:218–22.analysis of 114 cases. Adv Exp Med Biol 1985;193:13–9.124. Oseroff AR, Shanler SD, Buscaglia DA, van Leengoed E, Conti

142. Pennington DG, Waner M, Knox A. Photodynamic therapy forC, Somers K, et al. PDT with topical delta-aminolevulinicmultiple skin cancers. Plast Reconst Surg 1987;82:1067–71.acid (ALA) for the treatment of patch and plaque stage cuta-

143. Waldow SM, Lobraico RV, Kohler IK, Wallk S, Fritts HT. Pho-neous T-cell lymphoma. Lasers Surg Med 1995;7(Suppl):39.todynamic therapy for treatment of malignant cutaneous125. Wolf P, Fink-Puches R, Cerroni L, Kerl H. Photodynamiclesions. Lasers Surg Med 1987;7:451–6.therapy for mycosis fungoides after topical photosensitiza-

144. Wilson BD, Mang TS, Cooper M. Use of photodynamic ther-tion with 5-aminolevulinic acid. J Am Acad Dermatol 1994;apy for treatment of extensive basal cell carcinomas. Facial31:678–80.Plast Surg 1989;6:185–9.126. Ammann R, Hunziker T. Photodynamic therapy for mycosis

145. Buchanan RB, Carruth JAS, McKenzie AL, Williams SR. Photo-fungoides after topical photosensitization with 5-aminolev-dynamic therapy in the treatment of malignant tumors of theulinic acid. J Am Acad Dermatol 1995;33:541.skin and head and neck. Eur J Surg Oncol 1989;15:400–6.127. Malik Z, Ehrenberg B, Faraggi A. Inactivation of erythrocytic,

146. Keller GS, Razum NJ, Doiron DR. Photodynamic therapy forlymphocytic and myelocytic leukemic cells by photoexcita-nonmelanoma skin cancer. Facial Plast Surg 1989;6:180–4.tion of endogenous porphyrins. J Photochem Photobiol B

147. McCaughan JS, Guy JT, Hicks W, Laufman L, Nims TA, J1989;4:195–205.Walker. Photodynamic therapy for cutaneous and subcuta-128. Boehncke WH, Sterry W, Kaufmann R. Treatment of psoria-neous malignant neoplasms. Arch Surg 1989;124:211–6.sis by topical photodynamic therapy with polychromatic

148. Feyh J, Goetz A, Muller W, Konigsberger R, Kastenbauer E.light. Lancet 1994;343:801.Photodynamic therapy in head and neck surgery. J Pho-129. Nelson JS, Jeffes EWB, Weinstein GD, McCullough JL. Topi-tochem Photobiol B 1990;7:353–8.cal 5-aminolevulinic acid (ALA) for the photodynamic ther-

149. Wilson BD, Mang TS, Stoll H, Jones C, Cooper M, Doughertyapy of psoriasis and actinic keratoses. Lasers Surg MedTJ. Photodynamic therapy for the treatment of basal cell1995;7(Suppl):43.carcinoma. Arch Dermatol 1992;128:1597–601.

130. Stringer MR, Collins P, Robinson DJ, Stables GI, Sheehan-150. Hintschich C, Feyh J, Beyer-Machule C, Riedel K, Ludwig K.

Dare RA. The accumulation of protoporphyrin IX in plaquePhotodynamic laser therapy of basal-cell carcinoma of the

psoriasis after topical application of 5-aminolevulinic acidlid. Ger J Ophthalmol 1993;2:212–7.

indicates a potential for superficial photodynamic therapy.151. Robinson PJ, Carruth JAS, Fairris GM. Photodynamic ther-J Invest Dermatol 1996;107:76–81.

apy: a better treatment for widespread Bowen’s disease. Br131. Ammann R, Hunziker T, Braathen LR. Topical photody-

J Dermatol 1988;119:59–61.namic therapy in verrucae. Dermatology 1995;191:346–7.

152. Jones CM, Mang T, Cooper M, Wilson BD, Stoll HL. Photody-132. Frank RGJ, Bos JD, vd Meulen FW, Sterenborg HJCM. Photo- namic therapy in the treatment of Bowen’s disease. J Am

dynamic therapy for condylomata acuminata with local ap- Acad Dermatol 1992;27:979–82.plication of 5-aminolevulinic acid. Genitourin Med 1996; 153. McCaughan JS. Photoradiation of malignant tumors photo-72:70–1. sensitized with hematoporphyrin derivative. In: Doiron DR,

133. Fehr MK, Chapman CF, Krasieva T, Tromberg BJ, McCul- Gomer CJ. Porphyrin localization and treatment of tumor.lough JL, Berns MW, et al. Selective photosensitizer distribu- New York: Alan R. Liss, Inc., 1984:805–27.tion in vulvar condyloma acuminatum after topical applica- 154. Bandieramonte G, Marchesini R, Melloni E, Andreoli C, dition of 5-aminolevulinic acid. Am J Obstet Gynecol 1996;174: Pietro S, Spinelli P, et al. Laser phototherapy following HpD951–7. administration in superficial neoplastic lesions. Tumor

134. Divaris DXG, Kennedy JC, Pottier RH. Phototoxic damage to 1984;70:327–34.sebaceous glands and hair follicles of mice after systemic 155. Petrelli NJ, Cebollero JA, Rodriguez-Bigas M, Mang T. Photo-administration of 5-aminolevulinic acid correlates with lo- dynamic therapy in the management of neoplasms of thecalized protoporphyrin IX fluorescence. Am J Pathol perianal skin. Arch Surg 1992;127:1436–8.1990;136:891–7. 156. Dilkes MG, Dejode ML, Gardiner Q, Kenyon GS, McKelvie

135. Grossman M, Wimberly J, Dwyer P, Flotte T, Anderson RR. P. Treatment of head and neck cancer with photodynamicPDT for hirsutism. Lasers Surg Med 1995;7(Suppl):44. therapy: results after one year. J Laryngol Otol 1995;109:

136. Dougherty TJ, Kaufman JE, Goldfarb A, Weishaupt KR, Boyle 1072–6.D, Mittleman A. Photoradiation therapy for the treatment 157. Wolf P, Fink-Puches R, Reimann-Weber A, Kerl H. Site andof malignant tumors. Cancer Res 1978;38:2628–35. surface fluorescence-dependent response of solar keratoses

137. Dougherty TJ. Photoradiation therapy for cutaneous and sub- to topical 5-aminolevulinic acid photodynamic therapycutaneous malignancies. J Invest Dermatol 1981;77:122–4. (ALA-PDT) by UVA and/or different wavebands of visible

138. Kennedy J. HPD photoradiation therapy for cancer at Kings- light. Photochem Photobiol 1996;63:22S.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


158. of delta-aminolevulinic acid: preliminary results. Lasers SurgSzeimies R-M, Karrer S, Sauerwald A, Landthaler M. Photo-Med 1995;7(Suppl):42.dynamic therapy with topical application of 5-aminolevu-

linic acid in the treatment of actinic keratoses: an initial 176. Kriegmair M, Baumgartner R, Lumper W, Waidelich R, Hofs-clinical study. Dermatology 1996;192:246–51. tetter A. Early clinical experience with 5-aminolevulinic acid

159. Rowe DE, Carroll RJ, Day CL. Long-term recurrence rates in for the photodynamic therapy of superficial bladder cancer.previously untreated (primary) basal cell carcinoma: impli- Br J Urol 1996;77:667–71.cations for patient follow-up. J Dermatol Surg Oncol 1989; 177. Leveckis J, Burn JL, Brown NJ, Reed MWR. Kinetics of endog-15:315–28. enous protoporphyrin IX induction by aminolevulinic acid:

160. Levy JG, Waterfield E, Richter A, Smits C, Lui H, Hruza L, et preliminary studies in the bladder. J Urol 1994;152:550–3.al. Photodynamic therapy of malignancies with bezoporphyrin 178. Iinuma S, Bachor R, Flotte T, Hasan T. Biodistribution andderivative monoacid ring A. Proc SPIE 1994;2078:91–101. phototoxicity of 5-aminolevulinic acid–induced PpIX in an or-

161. Levy JG, Chan A, Strong HA. The clinical status of bezo- thotopic rat bladder tumor model. J Urol 1995;153:802–6.porphyrin derivative. Proc SPIE 1996;2625:81–95. 179. van Staveren HJ, Beek JF, Verlaan CWJ, Edixhoven A, Saar-

162. Doiron DR, Razum NJ, Snyder AB, Crean DH. Clinical updatenak AE, et al. Whole bladder wall photodynamic therapy

of SnET2. Photochem Photobiol 1996;63:5S.using 5-ALA: an experimental study in pigs. Proc SPIE 1996;

163. Allen RP, Kessel D, Tharratt RS, Volz V. Photodynamic ther-2625:70–6.

apy of superficial malignancies with NPe6 in man. In: Spi-180. Chang SC, MacRobert AJ, Bown SG. Biodistribution of proto-nelli P, Fante MD, Marchesini R. Photodynamic therapy and

porphyrin IX in rat urinary bladder after intravesical instilla-biomedical lasers. Amsterdam: Elsevier Science Publisherstion of 5-aminolevulinic acid. J Urol 1996;155:1744–8.B.V., 1992:441–5.

181. Chang SC, MacRobert AJ, Bown SG. Photodynamic therapy164. Wieman TJ, Taber SW, Fingar VH. Photodynamic therapyon rat urinary bladder with intravesical instillation of 5-using NPe6 for the treatment of cutaneous disease. Pho-aminolevulinic acid: light diffusion and histological changes.tochem Photobiol 1995;61(Suppl):51S.J Urol 1996;155:1749–53.165. Grant WE, Hopper C, MacRobert AJ, Speight PM, Bown SG.

182. Marcus SL, Dugan MH. Global status of clinical photody-Photodynamic therapy of oral cancer: photosensitizationnamic therapy: the registration process for a new therapy.with systemic aminolevulinic acid. Lancet 1993;342:147–8.Lasers Surg Med 1992;12:318–24.166. Loh CS, MacRobert AJ, Regula J, Bown SG. Oral vs. i.v. ad-

183. Baumgartner R, Kriegmair M, Jocham D, Hofstetter A, Huberministration of 5-ALA. Br J Cancer 1993;68:41–51.R, Karg O, et al. Photodynamic diagnosis (PDD) of early167. Mlkvy P, Messmann H, Regula J, Conio M, Pauer M, Millsonstage malignancies: preliminary results in urology and pneu-CE, et al. Sensitization and photodynamic therapy (PDT)mology. Proc SPIE 1992;1641:107–12.of gastrointestinal tumors with 5-aminolevulinic acid (ALA)

induced protoporphyrin IX (PPIX): a pilot study. Neoplasma 184. Baumgartner R, Fuchs N, Jocham D, Stepp H, Unsold E.1995;42:109–13. Pharmacokinetics of fluorescent polyporphyrin Photofrin II

168. Fan K, Hopper C, Speight P, Buonaccorsi G, MacRobert A, in normal rat tissue and rat bladder tumor. Photochem Pho-Bown S. Photodynamic therapy with ALA sensitisation for tobiol 1992;55:569–74.dysplastic and microinvasive carcinoma of the mouth. La- 185. Kriegmair M, Baumgartner R, Lumper W, Riesenberg R,sers Surg Med 1995;7(Suppl):40. Stocker S, Hofstetter A. Fluorescence cystoscopy following

169. Mlkvy P, Messmann H, Debinski H, Regula J, Conio M, et al. intravesical instillation of aminolevulinic acid (ALA). J UrolPhotodynamic therapy for polyps in familial adenomatous 1993;149(Suppl):240A.polyposis: a pilot study. Eur J Cancer 1995;31A:1160–5. 186. Baumgartner R, Huber RM, Haubinger K, Gamarra F, Stepp

170. Warloe T, Peng Q, Heyerdahl H, Wæhre H, Moan J, Steen H, Rick K, et al. Inhalation of 5-ALA: a new technique forH, Giercksky K-E. Photodynamic therapy of human tubulo- fluorescence detection of neoplasias in the lung. An Interna-villous adenomas. Proc SPIE 1995;2325:425–36. tional Symposium on Biomedical Optics, San Jose, CA, Feb-

171. Gossner L, Sroka R, Hahn EG, Ell C. Photodynamic therapy: ruary 4–10, 1995. Technical Abstract, 126.successful destruction of gastrointestinal cancer after oral 187. Stummer W, Stepp H, Stocker S, Baumgartner R. Intra-oper-administration of aminolevulinic acid. Gastrointest Endosc

ative fluorescence detection of human malignant glioma by1995;41:55–7.

5-ALA induced protoporphyrin: first clinical experience. 6th172. Kriegmair M, Baumgartner R, Knuechel R, Steinbach P, Eh-

IPA meeting, 1996. Abstract book.san A, Lumper W, et al. Fluorescence photodetection of neo-

188. Stringer MR. Problems associated with the use of broad-plastic urothelial lesions following intravesical instillation ofband illumination sources for photodynamic therapy. Phys5-aminolevulinic acid. Urology 1994;44:836–41.Med Biol 1995;40:1733–5.173. Steinbach P, Kriegmair M, Baumgartner R, Hofstadter F,

189. Waldow SM, Dougherty TJ. Interaction of hyperthermia andKnuechel R. Intravesical instillation of 5-aminolevulinicphotoradiation therapy. Radiat Res 1984;97:380–5.acid: the fluorescent metabolite is limited to urothelial cells.

190. Kimel S, Svaasand LO, Hammer-Wilson M, Gottfried V,Urology 1994;44:676–81.Cheng S, Svaasand E, et al. Demonstration of synergistic174. Kriegmair M, Stepp H, Steinbach P, Lumper W, Ehsan A,effects of hyperthemia and photodynamic therapy using theStepp HG, et al. Fluorescence cystoscopy following intraves-chick chorioallantoic membrane model. Lasers Surg Medical instillation of 5-aminolevulinic acid: a new procedure1992;12:432–40.with high sensitivity for detection of hardly visible urothelial

191. Hisazumi H, Naito K, Misakii T, Koshida K, Yamamoto H.neoplasias. Urol Int 1995;55:190–96.An experimental study of photodynamic therapy using a175. Jichlinski P, Leisinger HJ, Forrer M, Mizeret J, Glanzmannpulsed gold vapor laser. In: Jori G, Perria C. PhotodynamicT, Wagnieres G, et al. Clinical evaluation of a screeningtherapy of tumors and other diseases. Padova: Libreria Pro-method of bladder transitional cell carcinoma by induced

fluorescence of protoporphyrin IX with topical application getto Editore, 1985:252–4.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer


192. 209. Charlesworth P, Truscott TG. The use of 5-aminolevulinicCowed PA, Grace JR, Forbes IJ. Comparison of the efficacyacid (ALA) in photodynamic therapy (PDT). J Photochemof pulsed and continuous-wave red laser light in inductionPhotobiol B 1993;18:99–100.of photocytotoxicity by hematoporphyrin derivative. Pho-

210. Konig K, Schneckenburger H, Ruck A, Steiner R. In vivo pho-tochem Photobiol 1984;39:115–7.toproduct formation during PDT with ALA-induced endoge-193. Barr H, Boules PB, MacRobert AJ, Tralau CJ, Phillips D, Bownnous porphyrins. J Photochem Photobiol B 1993;18:287–90.SG, et al. Comparison of lasers for photodynamic therapy

211. Ahram M, Cheong WF, Ward K, Kessel D. Photoproduct for-with a phthalocyanine photosensitizer. Lasers Med Scimation during irradiation of tissues containing protopor-1989;4:7–12.phyrin. J Photochem Photobiol B 1994;26:203–4.194. Moan J, Sommer S. Oxygen dependence of the photosensi-

212. Warloe T. Photodynamic therapy of human malignant tu-tizing effect of hematoporphyrin derivative in NHIK 3025mors [Ph.D dissertation]. The University of Oslo, 1995.cells. Cancer Res 1985;45:1608–10.

213. Heyerdahl H, Warloe T, Peng Q, Svanberg K, Moan J, Steen195. Moan J, Iani V, Ma LW. Choice of the proper wavelength forH, et al. Dosimetry and light distribution systems for photo-photochemotherapy. Proc SPIE 1996;2625:544–9.dynamic therapy at the Norwegian Radium Hospital. Proc196. Szeimies RM, Abels C, Fritsch C, Karrer S, Steinbach P,SPIE 1994;2078:27–36.Baumler W, et al. Wavelength dependency of photodynamic

214. Kloek J, van Henegouwen GMJB. Prodrugs of 5-aminolevu-effects after sensitization with 5-aminolevulinic acid in vitrolinic acid for photodynamic therapy. Photochem Photobioland in vivo. J Invest Dermatol 1995;105:672–7.1996;64:994–1000.197. Moan J, Berg K, Iani V. Action spectra of dyes relevant for

215. Peng Q, Moan J. Correlation of distribution of sulphonatedphotodynamic therapy. In: Moser JG. Quantitative data ofaluminum phthalocyanines with their photodynamic effect2nd and 3rd generation photosensitizers for photodynamicin tumour and skin of mice bearing CaD2 mammary carci-therapy. London: Harwood Academic Publishers. In press.noma. Br J Cancer 1995;72:565–74.198. Schneckenburger H, Konig K, Kunzi-Rapp K, Westphal-

216. Peng Q, Moan J, Ma LW, Nesland JM. Uptake, localizationFrosch C, Ruck A. Time-resolved in-vivo fluorescence ofand photodynamic effect of meso-tetra(hydroxyphenyl)por-photosensitizing porphyrins. J Photochem Photobiol Bphine and its corresponding chlorin in normal and tumor1993;21:143–7.tissues of mice bearing mammary carcinoma. Cancer Res199. Moan J, Iani V, Ma LW, Peng Q. Photodegradation of sensitiz-1995;55:2620–6.ers in mouse skin during PCT. Proc SPIE 1996;2625:187–92.

217. Hua Z, Gibson SL, Foster TH, Hilf R. Effectiveness of delta-200. Moan J, Høydalsvik E, Peng Q, Ma LW, Warloe T, Heyerdahlaminolevulinic acid–induced protoporphyrin as a photo-H. Measurements of sensitizer fluorescence in patients bysensitizer for photodynamic therapy in vivo. Cancer Resmeans of an ordinary fluorescence spectrometer. Proc SPIE1995;55:1723–31.1995;2371:516–9.

218. Regula J, Ravi B, Bedwell J, MacRobert AJ, Bown SG. Photo-201. Streckyte G, Berg K, Moan J. Photomodification of ALA-in-dynamic therapy using 5-aminolevulinic acid for experi-

duced protoporphyrin IX in cells in vitro. Proc SPIE 1995;mental pancreatic cancer-prolonged animal survival. Br J

2325:58–65.Cancer 1994;70:248–54.

202. Konig K, Meyer H, Schneckenburger H, Ruck A. The study219. Fukuda H, Paredes S, Batlle AMC. Tumor-localizing proper-

of endogenous porphyrins in human skin and their potentialties of porphyrins: in vivo studies using free and liposome

for photodynamic therapy by laser induced fluorescenceencapsulated aminolevulinic acid. Comp Biochem Physiol

spectroscopy. Lasers Med Sci 1993;8:127–32.1992;102B:433–6.

203. Inhoffen HH, Brockmann H, Bliesener KM. Photoproto- 220. Heyerdahl H, Wang I, Liu DL, Berg R, Andersson-Engels S,porphyrine und ihre Umwandlung in Spirographissowie Peng Q, et al. Pharmacokinetic studies on 5-aminolevulinicIsospirographis-porphyrin. Liebigs. Ann Chem 1969;730: acid-induced protoporphyrin IX accumulation in tumors173–85. and normal tissues. Cancer Lett 1997;112:225–31.

204. Cox GS, Krieg M, Whitten MG. Self-sensitized photo-oxida- 221. Svanberg K, Clemente LP, Clemente MP, Wang I, Warloetion of protoporphyrin IX derivatives in aqueous surfactant T, Andersson-Engels S, et al. Pharmacokinetic studies of d-solutions: product and mechanistic studies. J Am Chem Soc aminolevulinic acid–induced protoporphyrin IX build-up in1982;104:6930–7. some malignant tumours. Proc SPIE 1995;2387:30–42.

205. Cox GS, Bobillier C, Whitten DG. Photo-oxidation and sin- 222. Goldstein SR, Bonner RF, Grantham FH, Gullino P, Dedrickglet oxygen sensitization by protoporphyrin IX and its RLA. Fiber optic micro-fluorimeter for acute and chronic inphoto-oxidation products. Photochem Photobiol 1982;36: vivo studies. In: Eberhart RC. Advances in bioengineering.401–7. New York: American Society of Mechanical Engineers, 1978:

206. Krieg M, Whitten MG. Self-sensitized photooxidation of pro- 103–5.toporphyrin IX and related free-base porphyrins in natural 223. Frisoli JK, Tudor EG, Flotte TJ, Hasan T, Deutsch TF, Scho-and model membrane systems: evidence for novel photo- macker KT. Pharmacokinetics of a fluorescent drug usingoxidation pathways involving amino acids. J Am Chem Soc laser-induced fluorescence. Cancer Res 1993;53:5954–61.1984;106:2479–81. 224. Loh CS, Vernon D, MacRobert AJ, Bedwell J, Bown SG,

207. Cox GS, Whitten DG. Environmental effects on photochemi- Brown SB. Endogenous porphyrin distribution induced bycal reactions: contrasts in the photo-oxidation behavior of 5-aminolevulinic acid in the tissue layers of the gastrointes-protoporphyrin IX in solution, monolayer films, organized tinal tract. J Photochem Photobiol B 1993;20:47–54.monolayer assemblies, and micelles. J Am Chem Soc 1987; 225. Rittenhouse-Diakun K, van Leengoed H, Morgan J, Hryhoren-100:1293–5. ko E, Paszkiewicz G, Whitaker JE, et al. The role of transferrin

208. Gudgin EF, Pottier RH. On the role of protoporphyrin IX receptor (CD71) in photodynamic therapy of activated andphotoproducts in photodynamic therapy. J Photochem Pho- malignant lymphocytes using the heme precursor d-aminolev-

ulinic acid (ALA). Photochem Photobiol 1995;61:523–8.tobiol B 1995;29:91–3.

/ 7b58$$1130 05-22-97 08:19:01 cana W: Cancer

5-Aminolevulinic acid-based photodynamic therapy

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