Photodynamic therapy with violet light and topical δ-aminolaevulinic acid in the treatment of actinic keratosis, Bowen's disease and basal cell carcinoma

BACKGROUND: Most clinical studies using photodynamic therapy (PDT) with topical application of delta-aminolaevulinic acid (delta-ALA) use red light because it allows greater depth of penetration. However, given the porphyrin-like spectrum of delta-ALA-induced photosensitivity, violet light provides a maximal overlap with the excitation spectrum of protoporphyrin IX, meaning that PDT with violet light uses less light energy to induce the phototoxic reaction. AIM: To study the efficacy of violet light in combination with topical delta-ALA PDT in the treatment of pre-malignant and malignant skin lesions. METHODS: Eight hours after 20% delta-ALA was applied topically, photoirradiation was performed with an incoherent light source (Philips HPM-10, 400 W) emitting predominantly violet light (400-450 nm). Lesions received 10-20 J/cm2 during an exposure time of 30 min. The 38 subjects treated included three with basal cell naevus syndrome with multiple (> 30) superficial and nodular basal cell carcinomas (BCCs), one subject had multiple lesions of Bowen's disease, involving 50% of the scalp, and the remaining 34 subjects presented a total of 35 superficial BCCs, 10 nodular BCCs, four large solar keratoses and five solitary lesions of Bowen's disease. RESULTS: Complete remission both clinically and histologically was seen after a single treatment in 82% of the superficial BCCs (100% after a second treatment), 50% of the nodular BCCs, one of the four solar keratosis lesions (partial remission in the other three) and 90-100% of the solitary lesions of Bowen's disease. CONCLUSIONS: delta-ALA PDT using violet light appears to be a well tolerated and effective alternative treatment for premalignant and malignant skin lesions, especially when there are multiple lesions or large patches comprising a large area of skin.     

Photodynamic therapy of epithelial skin tumours using delta-aminolaevulinic acid and desferrioxamine

Photodynamic therapy (PDT) uses photosensitizing drugs, such as porphyrins, and light for cancer treatment. In the present clinical study we employed topical application of the porphyrin precursor delta-aminolaevulinic acid (ALA) in combination with desferrioxamine (df) for the induction of endogenous porphyrin synthesis. Irradiation was performed with a light source consisting of a halogen lamp with a red filter and a fibreoptic device. Irradiances ranged from 50 to 300mW/cm². We treated 49 patients with this PDT regimen. In 32 patients we treated a total of 34 superficial basal cell carcinomas (BCCs) and 22 nodular BCCs, in nine patients 43 solar keratoses, and in eight patients 10 lesions of Bowen's disease. After a single treatment, 30 (88.2%) of the superficial and seven (31.8%) of the nodular BCCs, 35 of 43 (81.4%) solar keratoses. and three (30%) of the Bowen's disease lesions showed complete remission. The post-treatment observation period was up to 20 months. Repeat therapy was required in six nodular and four superficial BCCs. Biopsies were obtained before treatment, and at variable intervals after treatment. Topical PDT of skin tumours with ALA-df-induced porphyrins is effective in the management of epithelial skin tumours.     

Our PDT experience in the treatment of non-melanoma skin cancer over the last 7 years

BACKGROUND: Topical photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) was first described by Kennedy et al. in 1990; currently, accumulated evidence shows that topical PDT is effective in the treatment of actinic keratoses, Bowen's disease and superficial basal cell carcinoma, being potentially advantageous where size, anatomical location or number of lesions limit the efficacy and/or the acceptability of conventional therapies. It involves the use of photosensitizing drugs and the administration of an appropriate light source to activate the sensitizing agent, which leads to the production of activated oxygen species for tissue destruction. The topically administered prodrug 5-ALA is converted within cells into the active photosensitizer protoporphyrin IX, via haem cycle, with preferential accumulation in tumour cells. METHODS: The authors describe their experience with topical PDT, using 20% 5-ALA and two different incoherent light sources, 'Waldman 1200 L' and 'VersaLight', in the treatment of non-melanoma skin cancer and precursor lesions. More than 100 patients were treated since 1997, with up to a 7-year follow-up period. RESULTS: Cases are illustrated and results are presented and discussed in the light of the relevant Literature. CONCLUSION: The study suggests that 5-ALA PDT is effective in the treatment of superficial skin cancer and premalignant lesions.     

Topical 5-aminolaevulinic acid photodynamic therapy for cutaneous lesions: outcome and comparison of light sources

BACKGROUND: Topical 5-aminolaevulinic acid (ALA) photodynamic therapy (PDT) is increasingly used for superficial non-melanoma skin cancers and their precursors. METHODS: We report our 3-year experience of topical ALA-PDT, with a preliminary comparison of the effects of broadband and laser light sources. RESULTS: We performed 688 treatments on 483 lesions in 207 patients. Complete clearance was achieved in 222/239 lesions of Bowen's disease (BD), superficial basal cell carcinoma (sBCC) and actinic keratosis (AK) (93%) - 117/129 BD (91%), 84/87 sBCC (97%) and 21/23 AK (91%), with a median follow up of 48 weeks. Broadband and laser light sources were of similar efficacy. Recurrences have occurred in 10.3% BD, 4.8% sBCC and 4.8% AK. Adverse effects from PDT were uncommon but included pigmentary change (2%) and minor scarring (2%). How-ever, severe pain was experienced in 16-21% of treatments using the high-output broadband and laser sources, but in only 2% with the low-output xenon arc source. CONCLUSION: Topical ALA-PDT is effective for BD, sBCC and AK and has been an invaluable addition to our dermatology service. Efficacy is similar for broadband and laser light sources, although treatment at higher surface irradiance may be painful, and excellent cosmetic results can be achieved.     

A follow-up study of recurrence and cosmesis in completely responding superficial and nodular basal cell carcinomas treated with methyl 5-aminolaevulinate-based photodynamic therapy alone and with prior curettage

BACKGROUND: Methyl 5-aminolaevulinate (mALA) is an ester derivative of 5-aminolaevulinic acid (ALA) with increased lipophilicity compared with ALA. OBJECTIVES: To assess long-term cure rate, cosmesis, recurrence rate and extent of fibrosis after mALA-based photodynamic therapy (PDT) of superficial and nodular basal cell carcinomas (BCCs) showing early complete response to treatment. METHODS: Of 350 BCCs treated, 310 responded completely. These were in 59 patients who were followed for 2-4 years (mean 35 months) after mALA-PDT. Nodular tumours were curetted before PDT, and mALA 160 mg g(-1) was applied to all tumours for 24 h or 3 h before illumination from a broad-band halogen light source with light doses from 50 to 200 J cm(-2). Fibrosis was assessed histologically in 23 biopsies. RESULTS: The overall cure rate for 350 BCCs, including non-responders and recurrences was 79%. Of 310 lesions, 277 (89%) remained in complete response, and the cosmetic outcome was excellent or good in 272 of the completely responding lesions (98%). Histological examination showed dermal fibrosis in one of 23 biopsies. CONCLUSIONS: We conclude that mALA-based PDT with prior curettage of nodular lesions is a promising new method for the treatment of BCC.     

Photodynamic therapy in the treatment of extensive Bowen's disease

Abstract Background: Surgical excision is the preferred method of eradicating Bowen′s disease (BD). Photodynamic therapy (PDT) has been successfully used for treatment of actinic keratosis, basal cell carcinoma, and BD. Objective: Our aim was to evaluate the efficacy and tolerability of PDT for treatment of extensive BD. Method: Eighteen patients with 23 biopsy-proven BD lesions were treated with PDT. We defined as extensive those lesions large than 3 cm. Methyl aminolevulinate cream was applied for 3 h before illumination with an light emitting diode light source at a wavelength of 630 nm (energy density of 37 J/cm2). Treatment was repeated 1 week later. Results: After 12 weeks of treatment, 22 of 23 BD lesions (90%) showed complete clinical response. Only three lesions recurred after a follow-up period of 12 months. Cosmetic outcome at 12 months was good or excellent in 94% of patients. Conclusion: Methyl aminolevulinate PDT is an effective treatment option for extensive BD with excellent cosmesis.     

Photodynamic therapy of non-melanoma malignant tumours of the skin using topical δ-amino levulinic acid sensitization and laser irradiation

Eighty basal cell carcinomas (BCCs) in 21 patients, 10 lesions of Bowen's disease in three patients, and four lesions of cutaneous T-cell lymphoma in two patients, were treated with photodynamic laser therapy (PDT), using topical application of the haem precursor δ-amino levulinic acid (ALA). The diagnoses were confirmed histologically prior to treatment. Fifty-five of the BCCs were superficial lesions, and 25 were nodular. Of the 80 BCCs, 39 (49%) were located on the trunk, 36 (45%) on the head and neck region, four (15%) on the leg and one on the arm. The two principal locations of the 10 Bowen's disease lesions were the leg (50%) and the trunk (40%). The T-cell lymphoma lesions were located on the shoulder and on the arm. A water-in-oil based cream containing 20% ALA was applied to the lesions, with a margin of about 10–20 mm beyond the visible tumour border, 4–6 h before the laser procedure. During this period of time the highly fluorescent and photodynamically active substance protoporphyrin IX (Pp IX) is synthesized via the haem cycle. Laser-induced fluorescence (LJF) was used for real-time monitoring of the Pp IX distribution in the tumour and in the normal surrounding skin, before and after treatment in all patients. Before laser treatment the Pp IX distribution demonstrated by LJF showed a demarcation between tumour and normal skin of about 15:1 for BCC and Bowen's disease, and 5:1 for T-cell lymphomas. Laser light from a pulsed frequency- doubled Nd: YAG laser pumping a dye laser with light emission at 630 nm was used for the therapy. The power density in the irradiation was kept below 110 mW/cm², in order to avoid hyperthermal effects. A total energy of 60 J/cm² was delivered for 10–20 min, depending on the tumour size. A complete response rate of 100% in superficial BCCs and 64% in nodular BCCs occurred after a single laser treatment, and a response rate of 100% was achieved after one additional treatment in the nodular BCCs. In the Bowen's disease lesions a complete response of 90% was obtained with a single treatment. Two of the four T-cell lymphomas resolved completely. The follow-up time was between 6 and 14 months.     

Efficacy of photodynamic therapy with topical 5‐aminolevulinic acid using intense pulsed light for Bowen’s disease

Photodynamic therapy (PDT) with topical 5‐aminolevulinic acid (ALA) is reported to be an effective and safe treatment for superficial non‐melanoma skin cancers. We have developed an photodynamic therapy with topical δ‐aminolevulinic acid (ALA‐PDT) protocol using intense pulsed light (IPL) for treating Bowen’s disease (BD). Three patients diagnosed with BD by skin biopsy were recruited in this study. They received IPL treatment after 3 h of occlusive dressing with application of ALA. This protocol was repeated every 2 weeks for a total of five sessions. The treated areas did not show any signs of BD for more than 1 year; therefore, it appeared that the affected areas showed improvement in all the patients. No patients withdrew from the study because of side‐effects. ALA‐PDT with IPL as a light source is well tolerated by patients and is beneficial for treating BD.     

Photodynamic therapy with delta-aminolaevulinic acid for nodular basal cell carcinomas using a prior debulking technique

The incidence of basal cell carcinomas (BCCs) is still increasing, and there is a demand for an easy, effective and selective non-invasive treatment such as topical photodynamic therapy (PDT). Twenty-three patients with 24 nodular BCCs were treated once with delta-aminolaevulinic acid (delta-ALA) PDT (100 mW cm(-2), 120 J/cm2) 3 weeks after prior debulking of the BCCs. Three months after PDT, all lesions were surgically excised and histopathologically evaluated for residual tumour. Twenty-two (92%) of the 24 nodular BCCs showed a complete response on clinical and histopathological examination. PDT for superficially abraded nodular BCCs with topically applied delta-ALA and the VersaLight as light source is an easy, effective and safe therapy, with excellent cosmetic results and no serious side-effects, in cases where non-surgical treatment of BCCs is indicated.     

Fractionated aminolevulinic acid–photodynamic therapy provides additional evidence for the use of PDT for non-melanoma skin cancer

Background Photodynamic therapy (PDT) is an accepted treatment for superficial basal cel carcinoma (sBCC) and Bowens disease. In Rotterdam, extensive preclinical research has lead to an optimized twofold illumination scheme for aminolevulinic acid–PDT (ALA‐PDT). Objective To provide additional evidence of ALA‐PDT for sBCC, Bowens disease (BD), nodular BCC (nBCC) and actinic keratosis (AK) using a 2‐fold illumination scheme after a single application of ALA. Methods Five hundred fifty‐two lesions (430 sBCC, 20 nBCC, 32 BD, 70 AK) were treated with ALA‐PDT using a twofold illumination scheme. ALA was applied topically for 4 h. Lesions were treated with two light fractions of 20 and 80 J/cm² separated by a 2‐h dark interval. Results After a minimum follow‐up of 12 months, in average follow‐up of 2 years, an overall complete response of 95% was seen for all lesions. For sBCC, the complete response at 2 years was 97% (for AK 98%, for BD 84% and for nBCC 80% after 2 years). A sub‐analysis of the results of lesions larger than 2 cm showed CR at 2 years of 89% for all lesions (n = 57). Cosmetic outcome was good to excellent in 95% of the treated lesions. Conclusion ALA‐PDT using a twofold illumination scheme of 20 plus 80 J/cm² separated by a 2‐h dark interval leads to high complete response rates at 2 years and can be regarded as an evidence‐based treatment modality for superficial growing non‐melanoma skin cancer and the (pre)malignant AK. The Rotterdam fractionated approach should be included in future guidelines.     

Guidelines for topical photodynamic therapy: report of a workshop of the British Photodermatology Group

Topical photodynamic therapy (PDT) is effective in the treatment of certain non-melanoma skin cancers and is under evaluation in other dermatoses. Its development has been enhanced by a low rate of adverse events and good cosmesis. 5-Aminolaevulinic acid (ALA) is the main agent used, converted within cells into the photosensitizer protoporphyrin IX, with surface illumination then triggering the photodynamic reaction. Despite the relative simplicity of the technique, accurate dosimetry in PDT is complicated by multiple variables in drug formulation, delivery and duration of application, in addition to light-specific parameters. Several non-coherent and coherent light sources are effective in PDT. Optimal disease-specific irradiance, wavelength and total dose characteristics have yet to be established, and are compounded by difficulties comparing light sources. The carcinogenic risk of ALA-PDT appears to be low. Current evidence indicates topical PDT to be effective in actinic keratoses on the face and scalp, Bowen's disease and superficial basal cell carcinomas (BCCs). PDT may prove advantageous where size, site or number of lesions limits the efficacy and/or acceptability of conventional therapies. Topical ALA-PDT alone is a relatively poor option for both nodular BCCs and squamous cell carcinomas. Experience of the modality in other skin diseases remains limited; areas where there is potential benefit include viral warts, acne, psoriasis and cutaneous T-cell lymphoma. A recent British Photodermatology Group workshop considered published evidence on topical PDT in order to establish guidelines to promote the efficacy and safety of this increasingly practised treatment modality.     

Photodynamic therapy for large or multiple patches of Bowen disease and basal cell carcinoma

BACKGROUND: Photodynamic therapy (PDT) using topical delta-aminolevulinic acid (delta-ALA) is an effective treatment for Bowen disease and certain basal cell carcinomas (BCCs), but its place in clinical practice remains to be established. Patients with large and/or multiple lesions of Bowen disease or BCC can represent a considerable therapeutic challenge. We suggest that delta-ALA PDT may be of particular benefit in such patients. OBSERVATION: In an open study, 35 (88%) of 40 large patches of Bowen disease, all with a maximum diameter greater than 20 mm, cleared following 1 to 3 treatments of delta-ALA PDT, although 4 patches recurred within 12 months. delta-Aminolevulinic acid PDT was also used to treat 40 large BCCs, with an identical 88% initial clearance (after 1-3 treatments), with 4 recurrences within 34 months (range, 12-60 months). In 10 further patients with multiple (> or =3) patches of Bowen disease, 44 (98%) of 45 patches cleared following delta-ALA PDT, although 4 lesions recurred over 12 months. In 3 patients with multiple BCCs, PDT cleared 52 (90%) of 58 lesions, with 2 recurrences during 41 months (range, 12-52 months). Treatments were well tolerated, with only 5 patients with solitary large lesions requiring local anesthesia. CONCLUSIONS: delta-Aminolevulinic acid PDT is an effective tissue-sparing modality achieving good cosmesis. We propose that delta-ALA PDT be considered as a first-line therapy for large and/or multiple areas of Bowen disease and superficial BCCs.     

Photodynamic therapy for superficial basal cell carcinoma and Bowen's disease

Photodynamic therapy (PDT) is an effective treatment for superficial basal cell carcinoma (BCCs) and Bowen's disease. Several studies have reported complete response rates of 80-95% and an excellent cosmetic outcome. Bowen's disease and superficial basal cell carcinomas characteristically affect older patients who may also have associated difficulties with mobility. Using a portable PDT light source we were able to deliver PDT in a community setting with the aim of providing a more convenient service for patients. This randomised study confirmed that community delivered PDT is a viable treatment option and can be administered safely in the community by a trained dermatology nurse. The results from patient questionnaires suggest that community delivered PDT is more convenient to the patient, and also cost effective.     

Non‐invasive management of non‐melanoma skin cancer in patients with cancer predisposition genodermatosis: a role for confocal microscopy and photodynamic therapy

Background Patients with genodermatosis such as Gorlin syndrome (GS) and Xeroderma pigmentosum (XP) require a close follow‐up for early diagnosis and treatment of skin cancer. We aimed to evaluate the efficacy of methyl‐aminolevulinate (MAL) photodynamic therapy (PDT) in basal cell carcinomas (BCCs) from patients with GS and XP, and to determine the utility of reflectance confocal microscopy (RCM) in the diagnosis and the evaluation of therapeutic response. Patients and methods We included four patients with GS and two siblings with XP. Single or multiple lesions in localized areas were treated with 1–3 cycles of MAL PDT. RCM was performed before and 3 months after the treatment in target lesions in all the patients. Patients were followed up for 3 years. Results In XP patients, we treated 13 pigmented BCCs on the face. All the lesions responded to the treatment and six lesions showed a complete clinical clearing. In GS patients, facial or trunk areas with multiple BCCs were treated (up to 200). Complete clinical remission was obtained in 25–67% of the lesions. Some nodular and pigmented lesions failed to achieve a complete remission. RCM could identify already described confocal features for BCC. Tumour remissions could be assessed by this technique. Conclusions Methyl‐aminolevulinate PDT may be useful for the treatment of superficial BCC in GS and XP. In some nodular lesions, PDT may complement surgery reducing tumour size. RCM may be regarded in the future as a complementary technique in BCC for the diagnosis and post‐treatment assessment to non‐invasive therapeutic modalities.     

Photodynamic therapy for basal cell carcinoma: clinical and pathological determinants of response

Background Photodynamic therapy (PDT) is increasingly used in the treatment of basal cell carcinoma (BCC). However, scant information is available about the impact of both patient‐ and lesion‐related characteristics on the effectiveness of therapy. Therefore, on the basis of the current data, it is difficult to draw clear‐cut indications to use PDT for treatment of BCC in clinical practice. Objective To investigate the clinical and pathological determinants of response of BCC to PDT with methylaminolevulinate (MAL) and red light. Methods The clinical and pathological characteristics of 194 BCCs in 135 patients, treated with MAL‐PDT, were evaluated. Lesions were treated with MAL‐PDT according to established methods and the response was assessed by clinical follow‐up of the patients. Results Complete response to PDT was 62%, with a better response for superficial BCC (95/116, 82%) than nodular BCC (26/78, 33%). When determinants of response were analysed, the nodular type and the location on the limbs emerged as significant clinical predictors of failure. Among the pathological characteristics, the nodular and infiltrative histotypes, as well as ulceration and tumour thickness were associated with a lower response to therapy. Patients’ age and gender, as well as the size of the lesions, were not found to be significant predictors. Conclusions Optimization of PDT procedure for BCC requires a careful selection of the lesions. In particular, superficial BCCs, preferentially located on the trunk, show the best therapeutic response.     

Randomized comparison of photodynamic therapy with topical 5-fluorouracil in Bowen's disease

BACKGROUND: Bowen's disease (BD; intraepithelial squamous cell carcinoma) is therapeutically challenging because lesions, which may be multiple, are frequently located at sites that heal poorly. There is a small risk of progression to invasive carcinoma. Photodynamic therapy (PDT) is an effective treatment for certain non melanoma skin cancers, but comparison studies with other, better-established therapies are limited. OBJECTIVES: To compare the efficacy and tolerability of PDT and topical 5-fluorouracil (5-FU) in BD. METHODS: Forty patients from two centres were randomized to either topical PDT or 5-FU. The PDT group was treated with 20% 5-aminolaevulinic acid (ALA) applied 4 h before illumination with 100 J cm-2 narrowband red light (630 +/- 15 nm). 5-FU was applied to lesions for 4 weeks. A repeat treatment cycle was performed after 6 weeks if required. Results Twenty-nine of 33 (88%) lesions treated with PDT initially responded completely, compared with 22 of 33 (67%) after 5-FU. After 12 months, two recurrences in the PDT group and six in the 5-FU group reduced complete clinical clearance rates to 82% and 48%, respectively. PDT was significantly more effective (P = 0.006, odds ratio 4.78, 95% confidence interval 1.56-14.62). In the 5-FU group, severe eczematous reactions developed around seven lesions, ulceration in three and erosions in two. No such reactions occurred following PDT. There was no difference in overall pain experienced during each therapy. CONCLUSIONS: Topical ALA-PDT is more effective than topical 5-FU in the treatment of BD, with fewer adverse events. ALA-PDT should be considered one of the first-line therapeutic options for BD.     

Photodynamic therapy: a review of the literature and image documentation

Photodynamic therapy (PDT) consists of a chemical reaction activated by light energy that is used to selectively destroy tissue. The reaction requires a photosensitizer in the target tissue, a light source and oxygen. The most extensively studied photosensitizing agents for PDT are 5-aminolevulinic acid for the treatment of actinic keratosis and methyl-aminolevulinate, which has been approved for the treatment of actinic keratosis, basal cell carcinoma and Bowen's disease. The light sources used in photodynamic therapy should emit light at wavelengths within the absorption spectrum of the photosensitizer used in PDT treatment. Light emitting diode (LED) lamps are indicated for the photodynamic treatment of nonmelanoma skin cancer. PDT should be considered as a therapeutic option, particularly in the case of patients with superficial, multiple or disseminated lesions and for immunosuppressed patients. More recently, PDT has been indicated for a wide range of dermatological conditions such as photo-damaged skin, acne, hidradenitis, scleroderma, psoriasis, warts and leishmaniosis, among others. This article provides an extensive review of photodynamic therapy, its mechanisms, indications and results.     

Photodynamic therapy for basal cell carcinomas in organ-transplant recipients

The incidence of nonmelanoma skin cancer is significantly increased in recipients of solid-organ transplants. Photodynamic therapy (PDT) is a well-documented treatment option for superficial and selected nodular basal cell carcinomas (BCCs) in immunocompetent patients, but there are few reports describing PDT of BCCs in organ-transplant recipients (OTRs). We report a study of 18 OTRs with BCC on the head and trunk, who were treated with PDT, using methyl aminolevulinate as photosensitizer. There was only one recurrence during a total follow-up period of 407 months. PDT seems to be an effective treatment option for BCC in immunosuppressed OTRs.     

Photodynamic therapy vs. cryosurgery of basal cell carcinomas: results of a phase III clinical trial

BACKGROUND: A previously reported randomized clinical trial showed treatment of Bowen's disease using photodynamic therapy (PDT) with topically applied delta-aminolaevulinic acid (ALA) to be at least as effective as cryosurgery and to be associated with fewer adverse effects. OBJECTIVES: To compare ALA-PDT and cryotherapy in the treatment of histopathologically verified basal cell carcinomas (BCCs) in a non-blinded, prospective phase III clinical trial. METHODS: One lesion from each of 88 patients was included. The BCCs were divided into superficial and nodular lesions. The follow-up period was restricted to 1 year with close follow-up for the first 3 months. Efficacy was assessed as the recurrence rate 12 months after the first treatment session, verified by histopathology. Tolerability was evaluated as the time of healing, pain and discomfort during and after the treatment, and final cosmetic outcome. RESULTS: Histopathologically verified recurrence rates in the two groups were statistically comparable and were 25% (11 of 44) for ALA-PDT and 15% (six of 39) for cryosurgery. However, clinical recurrence rates were only 5% (two of 44) for PDT and 13% (five of 39) for cryosurgery. Additional treatments, usually one, had to be performed in 30% of the lesions in the PDT group. The healing time was considerably shorter and the cosmetic outcome significantly better with PDT. Pain and discomfort during the treatment session and in the following week were low, and were equivalent with the two treatment modalities. CONCLUSIONS: In terms of efficacy, ALA-PDT is comparable with cryosurgery as a treatment modality for BCCs. Retreatments are more often required with PDT than with cryosurgery. This can easily be performed due to the shorter healing time, less scarring and better cosmetic outcome that follows ALA-PDT.     

Role of Lasers and Photodynamic Therapy in the Treatment of Cutaneous Malignancy

Tumor therapy is not a common indication for the use of lasers, as it is in the treatment of benign vascular skin lesions, since many alternative treatment modalities exist. However, certain patients may benefit from laser therapy of premalignant and malignant skin tumors. Skin tumors can be treated by laser excision, laser coagulation, laser vaporization, or photodynamic therapy (PDT). For these purposes, the carbon dioxide laser, the neodymium:yttrium aluminum garnet laser and the argon laser are particularly suitable. PDT is a therapeutic approach based on the photosensitization of the target tissue by topical or systemic photosensitizers and subsequent irradiation with light from a laser or a lamp inducing cell death via generation of reactive oxygen species. Laser therapy and PDT have shown good results in the curative treatment of actinic keratoses, superficial basal cell carcinoma, Bowen’s disease and cheilitis actinica. However, they are not recommended for primary malignant melanoma and invasive squamous cell carcinoma. In some patients, lasers and PDT might also be used effectively for the palliative treatment of cutaneous metastases. In selected patients, lasers and PDT may offer some advantages over routine procedures, e.g. reduction of scarring and better cosmetic results. However, when treating invasive tumors with curative intention, one has to bear in mind the lack of histologic control and the limited depth of tissue penetration of most laser and PDT therapies.