Guidelines on the use of photodynamic therapy for nonmelanoma skin cancer: An international consensus

Photodynamic therapy targets the mTOR signaling network in vitro and in vivo

Mammalian target of rapamycin (mTOR) is a regulator of cell growth and proliferation and its activity is altered in many human cancers. The main objective of this study was to evaluate in vitro and in vivo targeting of mTOR by photodynamic therapy (PDT), a treatment modality for cancer. The amphiphilic endolysosomal localizing photosensitizer AlPcS(2a) and the p53 mutated rapamycin-resistant colon adenocarcinoma cell line WiDr were used as models. AlPcS(2a)-PDT downregulated the levels of Ser(2448) phosphorylated mTOR (p-mTOR), total mTOR and phosphorylation of ribosomal S6 (p-S6) immediately after light exposure in a dose-dependent manner, indicating a direct targeting of the mTOR signaling network. Low-dose PDT attenuated the level of p-mTOR in a transient manner; approximately 35% reduction of p-mTOR was obtained 5 min after a LD(35) PDT dose, but returned to the basal level 24 h later. Treatment with the mTOR inhibitor rapamycin reduced the p-mTOR level by 25% after 4-24 h of incubation. Combination treatment of rapamycin and PDT in vitro resulted in synergistic cytotoxic effects when rapamycin was administered after PDT. However, antagonistic effects were obtained when rapamycin was incubated both before and after PDT. In vivo, activated mTOR in the WiDr-xenografts was downregulated by 35 and 75% 5 min and 24 h post PDT respectively as measured by immunoblotting. In contrast to untreated tumors where p-mTOR expression was found throughout the tumors, immunohistochemical staining revealed only expression of p-mTOR in the rim of the tumor at 24 and 48 h post PDT. In conclusion, AlPcS(2a)-PDT is a novel mTOR-targeted cancer therapy. Rapamycin synergistically enhances the cytotoxicity of PDT only when administered post light exposure.

Photodynamic therapy of eyelid basal cell carcinoma

BACKGROUND

Photodynamic therapy (PDT; i.e. selective destroying of malignant cells by exposing them to red light after photosensitization) has been increasingly used for non-melanoma skin cancers. Due to excellent cosmetic and functional results, especially in difficult-to-treat areas, it may offer a comprehensive alternative to previous treatment modalities.

OBJECTIVE

A series of six patient cases was used to evaluate the efficacy of PDT in the treatment of lower eyelid basal cell carcinoma (BCC). Methods Histological confirmation of BCC, a detailed demonstration of the technique with an illustrative series of cases and a review of related literature.

RESULTS

Six patients with lower eyelid BCC were treated with two treatment sessions of PDT within a week. Five patients had a nodular type and one patient had a superficial type of BCC. The follow-up after treatment continued for 20-36 (mean 26.5) months. No recurrences were observed during the follow-up. All the patients were satisfied with the good results and tolerated the treatment well without any harm to the eyeball or surrounding skin.

CONCLUSION

PDT, although experimental in the eyelid area because of the small amount of data and the lack of a long-term follow-up, may be considered a promising comprehensive alternative when treating BCC in the eyelid area.

Topical methyl aminolevulinate photodynamic therapy using red light-emitting diode light for multiple actinic keratoses: a randomized study

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for actinic keratoses (AKs). Light-emitting diodes (LEDs) offer practical advantages when treating multiple lesions.

OBJECTIVE

To evaluate the efficacy and tolerability of PDT using a LED and topical methyl aminolevulinate (MAL) for treatment of multiple AKs.

METHODS AND MATERIALS

One hundred thirty-one patients with four to 10 non-pigmented, previously untreated thin or moderately thick AKs on the face or scalp were enrolled in this multicenter, double-blind, randomized, placebo-controlled study. MAL or matching placebo cream was applied to the débrided lesion surface for 3 hours before illumination with noncoherent red light (630 nm, light dose 37 J/cm(2)). Treatment was repeated 1 week later.

RESULTS

Efficacy was evaluated in 57 patients with 418 lesions treated with MAL PDT and 58 with 414 lesions treated with placebo PDT. Sixteen patients were excluded as protocol violators (not randomized). MAL PDT was superior (p< .001) to placebo PDT in lesion complete response rates (83.3%, 95% confidence interval (CI)=79.3-86.7%, vs 28.7%, 95% CI=24.4-33.4%) and patient complete response rates (all lesions showing complete response; 68.4%, 95% CI=54.8-80.1% vs 6.9%, 95% CI=1.9-16.7%).

CONCLUSIONS

Topical MAL PDT using a LED is an effective treatment for multiple AKs.

Pharmacoeconomic considerations in treating actinic keratosis

Actinic keratosis is among the most commonly treated skin conditions in the outpatient setting. Its prevalence spans the globe, with greater distribution in fair skinned individuals and the immunocompromised. With high prevalence, increasing incidence and the risk of transformation to a cancerous lesion, prevention and timely treatment present opportunities to rein in costs. The purpose of this article is to review published economic studies relating to the treatment of actinic keratosis, to summarize results discussing the cost drivers of current treatment modalities and to identify parameters most likely to influence the cost effectiveness of treatment. We systematically conducted a published literature search for pharmacoeconomic research of actinic keratosis using title, abstract or full-text searches with the following search terms ([actinic OR solar] AND [keratosis OR keratoses]) AND (economic OR cost OR pharmacoeconomics OR decision). We included published articles referencing actinic keratosis in a standalone study or in a broader study referencing non-melanoma skin cancer and articles evaluating cost-of-illness, cost-of-treatment, cost minimization, cost effectiveness, cost utility, cost-benefit analysis and cost consequence. Our review of the literature found nine studies devoted to pharmacoeconomic considerations of actinic keratosis treatments, with one article investigating both cost-of-illness and cost-of-treatment, two measuring cost-of-illness, two evaluating cost-of-treatment, one focusing on cost minimization, and three focusing on cost effectiveness. The literature compared a broad range of actinic keratosis treatments including topical medications, cryotherapy, photodynamic therapy, excision and a combination of treatment modalities. The direct cost of actinic keratosis management in the US was estimated at $US1.2 billion per year, with indirect costs totalling $US295 million (year 2004 values). The primary drivers of cost were physician office visits and associated procedures. Pharmacoeconomic research defining standards, outcomes and areas of efficiencies in the treatment of actinic keratosis is in its infancy. To move towards more comprehensive analysis, research needs to focus on updating epidemiological data, evolving evidence-based standards, delineating cost drivers in immunocompetent and immunocompromised populations, and on health outcomes.

Guidelines for the management of basal cell carcinoma

This article represents a planned regular updating of the previous British Association of Dermatologists guidelines for the management of basal cell carcinoma. These guidelines present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation.

Photodynamic therapy with 5-aminolaevulinic acid, dimethylsulfoxide and curettage in basal cell carcinoma: a 6-year clinical and histological follow-up

BACKGROUND

Long-term follow-up data are needed to evaluate treatment effect after photodynamic therapy (PDT).

OBJECTIVE

To investigate long-term clinical, histological and cosmetic follow-up results in basal cell carcinoma (BCC) after PDT, including treatment response related to patients and lesion characteristics.

MATERIALS AND METHODS

A longitudinal study of 44 patients with 60 histologically verified BCC tumours, treated with one or two sessions of dimethylsulfoxide (DMSO)-supported 5-aminolaevulinic acid--PDT following curettage, was performed. Lesions in complete remission after 3 months were followed with clinical inspection, histological investigation and evaluation of cosmetic outcome at regular intervals; long-term efficacy assessed as verified recurrence within 72 months after PDT.

RESULTS

Complete remission at 3 months was achieved in 55 lesions from 39 patients. Two patients with one lesion each died. At 72 months, 43 of 53 lesions remained disease-free (81%); 68% remained after one treatment session, and 91% remained after two treatment sessions. Recurrence of tumour occurred at 6, 12, 24 and 36 months in 2, 4, 2 and 2 lesions, respectively; clinical investigation identified 97% of them. Male sex and H-mid-face zone were significantly associated with recurrence. The cosmetic outcome at 72 months was rated as good or excellent by patients and investigators in more than 90% of evaluated cases.

CONCLUSION

DMSO-PDT following curettage is an effective treatment for BCC, with favourable long-term clinical, histopathological and cosmetic results. Clinical examination of treated lesions appears to be sufficient for long term follow up.

Effect of (R)L-sulforaphane on 5-aminolevulinic acid-mediated photodynamic therapy

Topical photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA), or so-called ALA-PDT, is a standard procedure in the clinical practice. For optimal treatment of nonmelanoma skin cancer, actinic keratoses and other dermatoses improvements are required because of adverse side effects, which include pruritus, erythema, edema, and pain. (R)L-sulforaphane (SF) is a compound that protects against erythema, but it can also induce DNA fragmentation that leads to cell death by apoptosis. The aim of our study was to investigate whether SF has any impact on protoporphyrin IX (PpIX) production and on PDT effectiveness. We have investigated some relevant properties of SF: its photostability in dimethyl sulfoxide (DMSO), its effect on ALA-induced production of PpIX in A431 human squamous carcinoma cells and in human skin, its effect on the photoinactivation of PpIX sensitized cells, and its effect on the rate of photobleaching of PpIX. SF had no influence on PpIX photodegradation, neither in solution nor in A431 cells. The synthesis of PpIX was increased by SF in human skin, but not in A431 cells. The average increase in PpIX fluorescence in human skin was 18% +/- 6% and 43% +/- 10% for ALA combined with 80 nmol/L SF and 120 nmol/L SF, respectively. Pretreatment with (R)L-sulforaphane before topical ALA-PDT may improve penetration of ALA through the stratum corneum, and, subsequently, increase PpIX synthesis.

Fractionated 5-aminolaevulinic acid-photodynamic therapy vs. surgical excision in the treatment of nodular basal cell carcinoma: results of a randomized controlled trial

BACKGROUND

Skin cancer incidence rates have been increasing for decades and this increase is expected to continue. Surgical excision (SE) is the treatment of first choice for nodular basal cell carcinoma (nBCC). Photodynamic therapy (PDT) has proven to be an effective treatment for superficial basal cell carcinoma. Its long-term efficacy in nBCC has not yet been established.

OBJECTIVES

Prospectively compare the efficacy of 5-aminolaevulinic acid (ALA)-PDT and SE in terms of failure rates with long-term follow-up. Determinants of failure in the study population, such as the effect of tumour depth, were analysed retrospectively.

METHODS

A randomized controlled trial in 173 primary nBCCs in 149 patients. Primary nBCCs were randomly assigned either to PDT (n = 85) or to SE (n = 88). Tumours treated with PDT were illuminated twice on the same day, 4 h after application of ALA cream, 3 weeks after debulking. SE was performed under local anaesthesia with a 3-mm margin, followed by histological examination. An intention-to-treat analysis was performed.

RESULTS

In total, 171 primary nBCCs in 149 patients were treated. A 3-year interim analysis revealed that the cumulative incidence of failure was 2.3% for SE and 30.3% for PDT (P < 0.001). Tumour depth and other analysed determinants of failure were not significantly related to treatment failure.

CONCLUSIONS

SE proved to be significantly more effective than treatment with fractionated illumination ALA-PDT. Therefore, in the treatment of primary nBCC, SE is preferred over PDT following this treatment regimen.

Bioavailability of aminolaevulinic acid and methylaminolaevulinate in basal cell carcinomas: a perfusion study using microdialysis in vivo

BACKGROUND

Photodynamic therapy is becoming a popular treatment for superficial nonmelanoma precancerous and cancerous lesions, showing excellent cosmetic results. Nevertheless, the reported cure rates vary and the transdermal penetration of drugs has been discussed as a limiting factor, particularly for treatment of nodular basal cell carcinoma (BCC).

OBJECTIVES

To investigate the transdermal penetration of aminolaevulinic acid (ALA) and methylaminolaevulinate (MAL) in BCC in vivo using a microdialysis technique. The different prodrugs were compared and the effect of curettage was studied.

METHODS

Twenty patients with 27 histologically verified BCCs (13 superficial, 14 nodular) were included. All lesions were located at the front of the body (head and face excluded). The first 10 patients included were treated with MAL (13 BCCs), and the following 10 patients with ALA (14 BCCs). A light curettage was performed on every second lesion (curettage, n = 13; noncurettage, n = 14). Microdialysis catheters were inserted into the tumours at tissue depths varying from 0.4 to 1.9 mm. Dialysates were collected at 15-30-min intervals for 4 h and the interstitial concentrations of MAL and ALA were determined using high-performance liquid chromatography.

RESULTS

No significant difference in interstitial drug concentration was observed between lesions treated with ALA or MAL during the 4-h measurement period. However, for the lesions with deeper catheter locations, i.e. at or below 1 mm (n = 11), drug concentrations above the detection limit were obtained in only six lesions. All but one BCC with superficial catheter location, i.e. < 1 mm (n = 16), exhibited detectable drug concentration (P = 0.026). The interstitial peak concentrations were reached within 90 min in 23 of the 27 BCCs, but were not found to be correlated with the depth of the catheters. No difference was found when comparing superficial and nodular BCCs, and the effect of curettage was found to be negligible.

CONCLUSIONS

The results imply that there is no significant difference in transdermal penetration of ALA and MAL in tumour tissue. Detectable levels of drug were not obtained in almost 50% of the lesions where catheters were situated 1-1.9 mm in the lesion. Curettage was not found to affect the interstitial concentration, indicating that penetration of drug indeed might be a problem when treating BCCs thicker than 1 mm.

Comparison of ALA- and ALA hexyl-ester-induced PpIX depth distribution in human skin carcinoma

Photodynamic therapy (PDT) based on the use of photoactivable porphyrins, such as protoporphyrin IX (PpIX), induced by the topical application of amino-levulinic acid (ALA) or its derivatives, ALA methyl-ester (m-ALA), is a treatment for superficial basal cell carcinoma (BCC), with complete response rates of over 80%. However, in the case of deep, nodular-ulcerative lesions, the complete response rates are lower, possibly related to a lower bioavailability of PpIX. Previous in vitro skin permeation studies demonstrated an increased penetration of amino-levulinic acid hexyl-ester (h-ALA) over ALA. In this study, we tested the validity of this approach in vivo on human BCCs. An emulsion containing 20% ALA (w/w) and preparations of h-ALA at different concentrations were applied topically to the normal skin of Caucasian volunteers to compare the PpIX fluorescence intensities with an optical fiber-based spectrofluorometer. In addition, the PpIX depth distribution and fluorescence intensity in 26 BCCs were investigated by fluorescence microscopy following topical application of 20% ALA and 1% h-ALA. We found that, for application times up to 24h, h-ALA is identical to ALA as a PpIX precursor with respect to PpIX fluorescence intensity, depth of penetration, and distribution in basal cell carcinoma, but has the added advantage that much smaller h-ALA concentrations can be used (up to a factor 13). We observed a non-homogenous distribution in BCCs with both precursors, independent of the histological type and depth of invasion in the dermis.

Topical methyl-aminolevulinate photodynamic therapy using red light-emitting diode light for treatment of multiple actinic keratoses: A randomized, double-blind, placebo-controlled study

BACKGROUND

The use of light-emitting diode light offers practical advantages in photodynamic therapy (PDT) with topical methyl-aminolevulinate (MAL) for management of actinic keratoses (AK).

OBJECTIVE

We sought to evaluate the efficacy of MAL PDT using red light-emitting diode light.

METHODS

We conducted a multicenter, double-blind, randomized study. A total of 49 patients with 363 AK lesions had 16.8% MAL cream applied under occlusion for 3 hours, and 47 patients with 360 AK lesions had vehicle cream similarly applied. The lesions were then illuminated (630 nm, light dose 37 J/cm2) with repeated treatment 1 week later. Complete lesion and patient (all lesions showing complete response) response rates were evaluated 3 months after last treatment.

RESULTS

MAL PDT was superior (P<.0001) to vehicle PDT with respect to lesion complete response (86.2% vs 52.2%, odds ratio 6.9 [95% confidence interval 4.7-10.3]) and patient complete response (59.2% vs 14.9%, odds ratio 13.2 [95% confidence interval 4.1-43.1]).

LIMITATIONS

The study population may not be representative of all patients with AK.

CONCLUSION

MAL PDT using red light-emitting diode light is an appropriate treatment alternative for multiple AK lesions.

A terapia fotodinâmica com ácido 5-aminolevulínico como modalidade de tratamento para neoplasias cutâneas não-melanoma

FUNDAMENTOS: A terapia fotodinâmica baseia-se na associação de fonte de luz e fotossensibilizador para destruir seletivamente as células. OBJETIVO: Avaliar os efeitos imediatos e tardios, a resposta clínica e os resultados estéticos da terapia fotodinâmica com ácido 5-aminolevulínico em neoplasias cutâneas não-melanoma. MÉTODOS: Trinta e quatro lesões, sendo 19 disceratoses de Bowen e 15 carcinomas basocelulares, foram submetidas à aplicação tópica e oclusiva do ácido 5-aminolevulínico a 20%, por seis horas, e posteriormente a sessão única de laser de diodo (630nm). RESULTADOS: Foram registrados: sensação de queimação durante as sessões; eritema, edema e erosões, nas primeiras 72 horas; cicatrização em média de quatro semanas; resultados estéticos variáveis de excelentes a bons. Aos três meses, a resposta clínica foi de 91,2%, sendo reduzida, aos 18 meses, para 73,3%, de modo similar tanto para disceratose de Bowen (72,2%) quanto para carcinoma basocelular (75%). Foi evidenciada relação de tendência linear entre a redução da freqüência da resposta clínica e o aumento da dimensão das neoplasias cutâneas não-melanoma (p<0,001). CONCLUSÃO: A terapia fotodinâmica com ácido 5-aminolevulínico tópico mostrou destacadas vantagens: minimamente invasiva no tratamento de lesões múltiplas em sessão única ou em sítios de pobre cicatrização com superioridade dos resultados estéticos. O tipo/subtipo(clínico e histopatológico), a dimensão e o adequado seguimento devem ser considerados para a sua indicação no tratamento de neoplasias cutâneas não-melanoma.

Effective photodynamic therapy of actinic keratoses on the head and face with a novel, self-adhesive 5-aminolaevulinic acid patch

BACKGROUND

Photodynamic therapy (PDT) is increasingly used for the treatment of actinic keratosis (AK).

OBJECTIVES

To investigate both the efficacy of different application times and the safety of a novel patch (PD P 506 A) containing aminolaevulinic acid in the PDT of mild to moderate AK.

METHODS

Applications of PD P 506 A for 0.5, 1, 2 and 4 h were compared in a multicentre, randomized, blinded-observer, parallel-group study. After patch removal, study lesions were illuminated with red light (lambda(em) approximately 630 nm; 37 J/cm(2)). Study lesions were not pretreated (e.g. by curettage) prior to PDT. Efficacy was evaluated 4 and 8 weeks after treatment. Safety and tolerability were determined through laboratory analyses and documentation of both local reactions and adverse events.

RESULTS

A total of 149 patients were initially enrolled. Of these, 140 patients (520 lesions) completed the study according to protocol. Eight weeks after treatment, 86% of the AK lesions (74% of the patients) treated with 4-h patch application showed complete clearance. The complete clearance rates of lesions (patients) for the 2-, 1- and 0.5-h treatment arms were 73% (47%), 72% (50%) and 51% (24%), respectively. Statistically, the 4-h application was identified as the 'best treatment'. Patients with clearance seemed to experience local reactions to a greater extent than patients without clearance. Local reactions to study treatments did not exceed the expected range.

CONCLUSIONS

The results of this first clinical efficacy study suggest excellent therapeutic outcomes with a single PD P 506 A PDT with a 4-h application.

A clinical study comparing methyl aminolevulinate photodynamic therapy and surgery in small superficial basal cell carcinoma (8-20 mm), with a 12-month follow-up

OBJECTIVE

To compare the efficacy and cosmetic outcome (CO) of photodynamic therapy with topical methyl aminolevulinate (MAL-PDT) with simple excision surgery for superficial basal cell carcinoma (sBCC) over a 1-year period.

METHODS

In this multicentre, randomised, controlled, open study, patients were treated at baseline either with MAL-PDT (two sessions, 7 days apart, repeated 3 months later if incomplete clinical response) or surgery (at baseline). Primary endpoints were clinical lesion response (CR) 3 months after last treatment and CO assessed by the investigator 12 months after last treatment. Secondary endpoints were CR at 12 months (i.e. recurrence) and CO assessed by the investigator at 3 and 6 months and by the patient at 3, 6 and 12 months.

RESULTS

Overall, 196 patients were enrolled with 1.4 sBCC lesions on average per patient. Mean lesion count reduction at 3 months was 92.2% with MAL-PDT vs. 99.2% with surgery [per protocol (PP) population] confirming the non-inferiority hypothesis (95% confidence interval, -12.1, -1.9). A total of 92.2% lesions showed CR at 3 months with MAL-PDT vs. 99.2% with surgery (PP population). At 12 months, 9.3% lesions recurred with MAL-PDT and none with surgery. CO was statistically superior for MAL-PDT at all time points. At 12 months, 94.1% lesions treated with MAL-PDT had an excellent or good CO according to the investigator compared with 59.8% with surgery. This difference was confirmed with the patients' assessment. The proportion of excellent CO markedly improved with time with MAL-PDT unlike surgery.

CONCLUSIONS

MAL-PDT offers a similarly high efficacy and a much better CO than simple excision surgery in the treatment of sBCC.

Treatment of melanoma and nonmelanoma skin cancer

The incidence of skin cancer is increasing in Caucasian populations worldwide. Treatment approaches for Nonmelanoma skin cancer (NMSC) are predominantly curative and surgery can be regarded as standard of care. Nevertheless, novel and less invasive topical therapy modalities like photodynamic therapy or local immune modifiers are in progress. In contrast to NMSC, the mortality of melanoma has not changed considerably over the last years and decades. Melanoma survival mainly depends on primary tumor thickness underlining the importance of primary and secondary prevention by avoidance or early detection of the disease. The chance to cure melanoma patients is steadily decreasing with tumor stage. As the prognosis in distant metastatic disease is still poor, except for single situations therapy approaches are palliative and accompanied by an optimal supportive care of the patients concerned. Albeit removal of localized metastases is currently the most effective approach in metastatic melanoma, chemo- and chemoimmunotherapy has to be regarded as standard treatment in most of the cases. Novel and promising therapeutic options accrue from growing insights in tumor biology and immunology. Not only in melanoma, development and application of targeted therapies currently attract the most attention in the treatment of advanced tumors. First clinical experiences with those antiproliferative, antiangiogenic and proapoptotic agents reveal only moderate antitumoral activity in melanoma, so that future efforts aim at defining more effective combination strategies using chemo-, targeted and vaccination therapy approaches.

Photodynamic therapy in dermatology--an update 2008

SUMMARY

Photodynamic therapy (PDT) is used for the prevention and treatment of non-melanoma skin cancer. Until recently, clinically approved indications have been restricted to actinic keratoses, nodular and superficial basal cell carcinoma, and--since 2006--Bowen disease. However, the range of indications has been expanding continuously. PDT is also used for the treatment of non-malignant conditions such as acne vulgaris and leishmaniasis, as well as for treating premature skin aging due to sun exposure. Here, PDT is used for the stimulation of immunomodulatory effects in contrast to the induction of necrosis and apoptosis as produced in the treatment of skin tumors. The porphyrin precursor 5-aminolevulinic acid (ALA) or its methyl ester (MAL, so far the only approved formulation in Europe) is applied topically as photosensitizer to exclude systemic reactions. Possible light sources include lasers as well as incoherent light sources; irradiation with incoherent light sources is cheaper and more appropriate for large treatment areas. The main advantages of PDT in comparison to other treatment modalities are its excellent cosmetic results and its high remission rates despite low invasiveness.This article provides up-to-date information about PDT with focus on recently published studies.

Multicentre intraindividual randomized trial of topical methyl aminolaevulinate-photodynamic therapy vs. cryotherapy for multiple actinic keratoses on the extremities

BACKGROUND

Methyl aminolaevulinate-photodynamic therapy (MAL-PDT) is an effective treatment in facial/scalp actinic keratosis (AK).

OBJECTIVES

The aims of this study were to compare efficacy, safety, cosmetic outcome and patient preference of MAL-PDT vs. cryotherapy in patients with AK at other locations.

METHODS

A multicentre, controlled, randomized, open, intraindividual, right-left comparison was performed. Patients with nonhyperkeratotic AK were treated once with MAL-PDT and cryotherapy on either side of the body. At week 12, lesions showing noncomplete response were retreated. The primary efficacy variable was the lesion response at week 24. Investigator's assessment of cosmetic outcome, patient's preference in terms of cosmetic outcome and a patient preference questionnaire were also analysed at week 24.

RESULTS

In total, of 121 patients with 1343 lesions (98% located on the extremities and the remainder on the trunk and neck) were included. Both treatments provided a high mean percentage reduction in lesion count at week 24 with significantly higher efficacy for cryotherapy: 78% for MAL-PDT and 88% for cryotherapy (P=0.002, per protocol population). Investigator's assessment of cosmetic outcome was significantly better for MAL-PDT than cryotherapy (P<0.001), 79% of lesions having an excellent cosmetic outcome with MAL-PDT vs. 56% with cryotherapy at week 24. The cosmetic outcome achieved by MAL-PDT compared with cryotherapy was also preferred by patients (50% vs. 22%, respectively, P<0.001), and 59% of patients would prefer to have any new lesions treated with MAL-PDT compared with 25% with cryotherapy (P<0.001). Both treatment regimens were safe and well tolerated.

CONCLUSIONS

MAL-PDT showed inferior efficacy for treatment of non-face/scalp AK compared with cryotherapy. However, both treatments showed high efficacy, and MAL-PDT conveyed the advantages of better cosmesis and higher patient preference.

Hypericin phototoxicity induces different modes of cell death in melanoma and human skin cells

Hypericin, the major component of St. John's Wort, absorbs light in the UV and visible ranges whereupon it becomes phototoxic through the production of reactive oxygen species. Although photodynamic mechanisms (i.e. through endogenous photosensitizers) play a role in UVA phototherapy for the treatment of skin disorders such as eczema and psoriasis, photodynamic therapy employing exogenous photosensitizers are currently being used only for the treatment of certain forms of non-melanoma skin cancers and actinic keratoses. There are few reports however on its use in treating melanomas. This in vitro study analyses the phototoxic effect of UVA (400-315 nm) - activated hypericin in human pigmented and unpigmented melanomas and immortalised keratinocytes and melanocytes. We show that neither hypericin exposure nor UV irradiation alone reduces cell viability. We show that an exposure to 1 microM UVA-activated hypericin does not bring about cell death, while 3 microM activated hypericin induces a necrotic mode of cell death in pigmented melanoma cells and melanocytes and an apoptotic mode of cell death in non-pigmented melanoma cells and keratinocytes. We hypothesis that the necrotic mode of cell death in the pigmented cells is possibly related to the presence of melanin-containing melanosomes in these cells and that the hypericin-induced increase in reactive oxygen species leads to an increase in permeability of melanosomes. This would result in toxic melanin precursors (of an indolic and phenolic nature) leaking into the cytoplasm which in turn leads to cell death. Hypericin localisation in the endoplasmic reticulum in these cells shown by fluorescent microscopy, further support a disruption in cellular processing and induction of cell death. In contrast, this study shows that cells that do not contain melanosomes (non-pigmented melanoma cells and keratinocytes) die by apoptosis. Further, using a mitochondrial-specific fluorescent dye, we show that intracellular accumulation of hypericin induces a mitochondrial-associated caspase-dependent apoptotic mode of cell death. This work suggests that UVA is effective in activating hypericin and that this phototoxicity may be considered as treatment option in some cases of lentigo maligna or lentigo maligna melanoma that are too large for surgical resection.

Photodynamic therapy in the treatment of actinic keratosis

The efficacy of photodynamic therapy (PDT) with 5-aminolevulinate and methyl aminolevulinate in the treatment of actinic keratosis has been demonstrated in a large number of clinical studies over the last several years. Here, we recapitulate the major findings, comparing the various photosensitizers, light sources and therapeutic regimens, and present a retrospective analysis of 142 own cases treated with 259 PDTs. In addition, we also discuss the value of PDT in comparison with cryotherapy or 5-fluorouracil. The efficacy and the low risk of side effects of PDT have resulted in a high patient preference in clinical trials.

[Side effects of topical photodynamic therapy]

Photodynamic therapy (PDT) is gaining increasing significance in the treatment of skin cancers and precancerous lesions. Most of the studies dealing with this procedure focus on efficacy. Whereas treatment results are a decisive parameter, before any therapy is accepted the evaluation should also consider side effects in daily practice. We treated 2031 patients with PDT between 2001 and 2006, and evaluated the side effects during and after treatment with a specially designed protocol. The most prominent side effect was pain, which occurred in 92% of patients, followed by erythema/edema (89%) and scaling in conjunction with itching (80%). Less common unwanted effects included crusting (9%), pustules (6%), large erosions (1.2%), pigmentary changes (1%) and infections (0.4%). Especially widespread erosions and pustules caused significant anxiety for the patients. Patients should be informed in detail about the side effects of PDT prior to treatment, since most of the unwanted effects are easily managed, heal without scarring and do not influence the therapeutic response.

[Photodynamic therapy in dermatooncology]

Non-melanoma skin cancers are the most common skin tumors. Because of their frequent localization on the face and hand, aesthetic aspects of the therapeutic procedures should also be considered. Surgical excision still remains the first choice, but recently several new alternative therapies have emerged, especially for the treatment of superficial skin cancer. Photodynamic therapy has become a widely accepted therapeutic method for certain non-melanoma skin tumors. Photodynamic therapy involves the use of light to activate a photosensitizer, localized in diseased tissues. Photosensitizers are tumor-selective: their accumulation in rapidly proliferating cells and newly formed blood vessels is significantly higher than in the surrounding healthy tissues. During photodynamic therapy, cytotoxic reactive oxygen species are formed from the photosensitizer, leading to changes in subcellular pathways or apoptosis of the cells. Efficacy of the photodynamic therapy has been proven in solar keratosis, superficial basal cell carcinoma and morbus Bowen, with significantly better cosmetic outcome than that of the conventional therapeutic methods. Side effects, like erythema, crusting, serous discharge, or oedema, are usually moderate, and dissolve rapidly. The present article summarizes the authors' experiences with photodynamic treatment (212 non-melanoma skin cancer patients were treated with PDT between December 2003 and January 2006), at the Department of Dermatology and Allergology, University of Szeged, Hungary, and reviews the literature of photodynamic therapy in dermatooncology.

Split-face-study using two different light sources for topical PDT of actinic keratoses:non-inferiority of the LED system

BACKGROUND

Photodynamic therapy (PDT) with 5-amino-4-oxo-pentanoate (methylaminolevulinate, MAL) is an effective and safe treatment option for actinic keratoses. Light-emitting diodes (LED) are suitable light sources for topical PDT. To evaluate the efficacy, painfulness, patient satisfaction and cosmesis of LED-based PDT a prospective, randomized and controlled split-face study was performed.

METHODS

Topical ALA-PDT was administered to 17 patients whose actinic ker-atoses (n = 131) were symmetrically distributed and suitable for a two-side comparison. After incubation with MAL (16%), irradiation was performed with the incoherent lamp (160 mW cm(-2); 100 J cm(-2), PDT 1200L, Waldmann Medizintechnik, Villingen-Schwenningen, Germany) on one side and the LED system (120 mW cm(-2); 40 J cm(-2), LEDA, WaveLight AG, Erlangen, Germany) on the other side. The patients were followed by re-evaluation up to 6 months.

RESULTS

Six months following treatment there was no significant difference between the infiltration and keratosis scores in both treatment regimes (p = 0.812). The remission rate was 78.5% (LED system) vs.80.3% (incoherent lamp). There was no significant difference between both light sources regarding the pain during therapy (p = 0.988). There was no significant difference between both treatment regimes regarding patient satisfaction (p = 1).

CONCLUSIONS

LEDA-based MAL-PDT is an effective alternative for the treatment of atinic keratoses. The remission rates and cosmetic results are not inferior to PDT using incoherent light systems. Both treatment regimes are similarly painful.

Milestones in the development of photodynamic therapy and fluorescence diagnosis

Many reviews on PDT have been published. This field is now so large, and embraces so many sub-specialties, from laser technology and optical penetration through diffusing media to a number of medical fields including dermatology, gastroenterology, ophthalmology, blood sterilization and treatment of microbial-viral diseases, that it is impossible to cover all aspects in a single review. Here, we will concentrate on a few basic aspects, all important for the route of development leading PDT to its present state: early work on hematoporphyrin and hematoporphyrin derivative, second and third generation photosensitizers, 5-aminolevulinic acid and its derivatives, oxygen and singlet oxygen, PDT effects on cell organelles, mutagenic potential, the basis for tumour selectivity, cell cooperativity, photochemical internalization, light penetration into tissue and the significance of oxygen depletion, photobleaching of photosensitizers, optimal light sources, effects on the immune system, and, finally, future trends.

Photodynamische Therapie bei epithelialen Hauttumoren

During the last years photodynamic therapy (PDT) has progressively established itself as a standard treatment for non-melanoma skin cancer. A number of clinical studies have demonstrated its efficacy--also compared to other treatment modalities--as well as good acceptance by patients and outstanding cosmetic results. For Bowen disease and superficial basal cell carcinoma, PDT can be regarded as the first-line non-invasive treatment. In the treatment of actinic keratoses PDT should be considered when cosmesis is crucial or in cases of field cancerization. In nodular basal cell carcinoma, effectiveness for lesions up to a thickness of 2 mm is well documented. In summary the evidence level seems sufficient to regard PDT as valuable treatment modality of which patients should not be deprived.