Role of lasers and photodynamic therapy in the treatment of cutaneous malignancy

Photodynamic therapy for leishmaniasis: Recent advances and future trends

Leishmaniasis has infected more than 12 million people worldwide. This neglected tropical disease, causing 20,000-30,000 deaths per year, is a global health problem. The emergence of resistant parasites and serious side effects of conventional therapies has led to the search for less toxic and non-invasive alternative treatments. Photodynamic therapy is a promising therapeutic strategy to produce reactive oxygen species for the treatment of leishmaniasis. In this regard, natural and synthetic photosensitizers such as curcumin, hypericin, 5-aminolevulinic acid, phthalocyanines, phenothiazines, porphyrins, chlorins and nanoparticles have been applied. In this review, the recent advances on using photodynamic therapy for treating Leishmania species have been reviewed.

Biogenic Gold Nanoparticles Decrease Methylene Blue Photobleaching and Enhance Antimicrobial Photodynamic Therapy

Antibiotic resistance is a growing concern that is driving the exploration of alternative ways of killing bacteria. Here we show that gold nanoparticles synthesized by the mycelium of Mucor plumbeus are an effective medium for antimicrobial photodynamic therapy (PDT). These particles are spherical in shape, uniformly distributed without any significant agglomeration, and show a single plasmon band at 522–523 nm. The nanoparticle sizes range from 13 to 25 nm, and possess an average size of 17 ± 4 nm. In PDT, light (from a source consisting of nine LEDs with a peak wavelength of 640 nm and FWMH 20 nm arranged in a 3 × 3 array), a photosensitiser (methylene blue), and oxygen are used to kill undesired cells. We show that the biogenic nanoparticles enhance the effectiveness of the photosensitiser, methylene blue, and so can be used to kill both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The enhanced effectiveness means that we could kill these bacteria with a simple, small LED-based light source. We show that the biogenic gold nanoparticles prevent fast photobleaching, thereby enhancing the photoactivity of the methylene blue (MB) molecules and their bactericidal effect.

Phototherapy of cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of non-Hodgkin lymphomas arising in the skin. Mycosis fungoides (MF), the most common variant, is characterised by clonal proliferation of skin residing malignant T-cells. Initially appearing with erythematous patches and plaques it follows a chronic course with progression to cutaneous tumours and extracutaneous involvement in some patients. Phototherapy with ultraviolet A radiation combined with 8-methoxypsoralen (PUVA) and with narrow-band ultraviolet B radiation (NB-UVB) are among the first line options for the treatment of MF and can induce remission in most patients. Sézary syndrome (SS) is a rare and more aggressive CTCL variant with generalized skin involvement. Patients with SS and with erythroderma from MF can benefit from treatment with extracorporeal photochemotherapy (ECP) where peripheral blood is exposed to PUVA. Phototherapy can be safely combined with systemic agents, most notably interferon-alpha and retinoids. Another photoresponsive CTCL variant is lymphomatoid papulosis (LP), a CD30+ lymphoproliferative disease characterised by chronically recurring papules. The disease responds favourably to PUVA but low dose methotrexate might be preferred for long term disease control. Recently updated treatment guidelines have been published to provide evidence-based algorithms for the stage-oriented treatment of MF, SS and LP. Areas of uncertainty are treatment schedules that are currently not optimised for CTCL, the use of phototherapy for maintenance, and the value of ultraviolet A1 radiation, excimer lasers, and photodynamic therapy.

Patient Responses to Cytoluminescent Therapy ® for Cancer: An Investigative Report of Early Experiences and Adverse Effects of an Unconventional Form of Photodynamic Therapy

Cytoluminescent Therapy ®(CLT) is an unconventional form of photodynamic therapy (PDT), utilizing a secondgeneration chlorophyll-derived photosensitizing agent and whole-body illumination. Starting in late 2002, CLT was administered in Ireland to 48 patients. Illumination with lasers and light-emitting diodes followed the administration of an initial bolus IV. After returning home, patients continued self-administered treatment using oral agent activated by infrared lamps. CLT proponents claimed that these procedures were beneficial to patients with advanced cancer. An organization devoted to making information on alternative therapies available to the public was engaged to contact these CLT patients and assess the outcome. In informal contacts, patients reported that initial side effects were generally mild and transient. However, especially after commencing self-treatment, many reported unanticipated effects, including fatigue and general weakness, increased pain, cough, dyspnea, diminished appetite and weight loss, tissue necrosis, and other major symptoms. At a minimum of 6 months after initial CLT, no patient has reported an objective response, and some have complained of deterioration on the home treatment. There have been 17 deaths among the 48, with a mean survival after initial treatment among decedents of 4.2 months. CLT, in this group, was a qualified failure, with a high incidence of aftereffects. The mode of action of these aftereffects has yet to be explored. In the future, CLT should be administered to patients only in carefully managed medical facilities, by fully trained and licensed professionals, under the supervision of relevant regulatory agencies, and with meticulous follow-up care.

[Therapy of basal cell carcinoma]

Basal cell carcinoma (BCC) represents the most common malignant skin tumour in fair-skinned people. Despite low metastatic potential, BCC can cause decisive tissue destruction and disfigurement by invasive growth. In addition to clinical and histologic diagnosis modern imaging techniques as optical coherence tomography and confocal laser microscopy have been introduced. BCCs with aggressive growth pattern and/or increased risk of relapse are preferentially treated surgically. For superficial BCCs various topical treatments and photodynamic therapy are available. Inhibitors of the sonic hedgehog pathway have been approved for symptomatic treatment of metastatic BCC and locally advanced BCC inappropriate for surgery or radiotherapy. Detailed knowledge of the clinical spectrum of BCC and an appropriate choice of therapy are mandatory for the successful treatment of BCC.

Efficacy of superficial and deep regional hyperthermia combined with systemic chemotherapy and radiotherapy in metastatic melanoma

BACKGROUND AND OBJECTIVE

Response rates of cutaneous-subcutaneous or lymph node metastases of melanoma to systemic chemotherapy are rather low. We report our clinical experience with superficial and deep regional hyperthermia in combination with radiotherapy and/or chemotherapy with carboplatin.

PATIENTS/METHODS

We treated 15 patients with metastatic melanoma (6 men, 9 women; age 39-84 years, mean age 60 years) by using superficial or deep regional hyperthermia produced by electromagnetic energy. Superficial hyperthermia was delivered to skin or lymph node metastases in combination with radiochemotherapy in 12 patients, while deep regional hyperthermia was administered with an annular array applicator to lymph node metastases either in combination with radiochemotherapy (1 patient) or with carboplatin alone (2 patients). The clinical response was assessed by clinical evaluation and/or computer tomography and/or ultrasonography at monthly intervals.

RESULTS

Both superficial and deep regional hyperthermia was well tolerated. We observed 5 complete local remissions (34%), 6 partial local remissions (40%) and 2 patients with stable disease (13%). The best results were obtained in cutaneous or retroperitoneal metastases.

CONCLUSIONS

Local response can be achieved in inoperable metastatic melanoma using superficial or deep regional hyperthermia in combination with radiochemotherapy or chemotherapy.

Metastatic malignant melanoma: computed tomography-guided 125I seed implantation treatment

The aim of this study is to evaluate the therapeutic efficacy of computed tomography (CT)-guided interstitial iodine-125 (I) seed implantation for metastatic malignant melanoma treatment. From November 2008 to May 2011, 24 patients with metastatic malignant melanoma who had undergone surgery for excision of primary lesions and repeated chemotherapy underwent CT-guided I seed implantation. Their clinical situations, biochemical indicators, MRIs, and CTs were observed. The follow-up time ranged from 5 to 24 months (mean 19.6 months). The local control rates of metastatic malignant melanoma after surgery excision for primary lesion after 2, 6, 12, and 24 months were 86.8, 78.6, 62.1, and 55.0%, respectively. One patient died of liver failure 5 months after brachytherapy and another died of a metastatic brain tumor 8 months after brachytherapy. Two patients died of lung dysfunction from pulmonary metastases 15 months after brachytherapy. All other patients survived throughout the follow-up period. The 2-year survival rate was 83.3%. During the procedure, one patient presented with minimal bleeding from the applicator route and another presented with pneumothorax with 20% pulmonary compression, which improved after intraprocedure suctioning. Four patients had low-grade fever on day 3. Three showed mild decreases in their white blood cell counts. CT-guided I seed implantation is a safe, feasible, and promising approach to the treatment of patients with metastatic malignant melanoma after surgery excision for primary lesions and repeated chemotherapy, but large-scale randomized clinical trials should be conducted before the technique can be used routinely.

Photodynamic therapy in dermatology: current concepts in the treatment of skin cancer

Photodynamic therapy is a treatment modality that is developing rapidly and increasing in utilization within various medical specialties, including dermatology. This technique requires the presence of a photosensitizer, light energy and molecular oxygen to selectively destroy pathologic cells. A thorough understanding of photobiology and tissue optics is necessary to correctly and effectively utilize photodynamic therapy in dermatology. Photodynamic therapy has been approved by the US Food and Drug Administration to treat actinic keratoses. In Europe, photodynamic therapy is currently being used in the treatment of actinic keratoses and basal cell carcinoma. Other off-label uses of photodynamic therapy have included cutaneous lesions of Bowen's disease, psoriasis, cutaneous T-cell lymphoma and acne. Most recently, photodynamic therapy has been employed in photorejuvenation. The advantages of photodynamic therapy include the capacity for noninvasive targeted therapy via topical application of the drug and local irradiation of involved areas, as well as the ability to generate excellent cosmetic results with minimal discomfort. This review summarizes the fundamentals of photodynamic therapy and its role in the treatment of cutaneous disorders, particularly skin malignancies.

Basalioma: diagnostics, treatment (part 2)

The author present data related to the diagnostics and therapy of basalioma. As many as 62 references are reviewed.

Photodynamic therapy in actinic cheilitis: clinical and anatomopathological evaluation of 19 patients

BACKGROUND

Actinic cheilitis, a common disease caused by chronic solar exposure and tobacco use, is considered a premalignant lesion with potential to develop into squamous cell carcinoma. Some of the available treatments are invasive, have unaesthetic results and require multiple sessions.

OBJECTIVE

To assess the efficacy of a therapy and its cosmetic results.

METHODS

In this uncontrolled clinical trial a single photodynamic therapy (PDT) session using 16% methyl-aminolevulinate was performed on actinic cheilitis of the lower lip. A standardized questionnaire was applied in order to assess the clinical improvement from the patients' point of view and the satisfaction with the treatment. Anatomopathological evaluation was performed before the treatment and two months afterwards.

RESULTS

The sample was composed of 19 patients (10 males and 9 females), phototypes I to III, with average age of 62 years. Main adverse effects were: sudden pain, scabs, herpes flare-up, and edema. The average score of pain during the procedure was 5,8+2,9. At the final assessment the patients reported improvement of 80% and satisfaction of 85% (p<0.01). Anatomopathological analysis showed a significant decrease of dysplasia (p=0.03) in spite of its presence in 84% of cases. There was no significant correlation between the level of dysplasia with either the subjective impression of clinical improvement (p=0.82) or with the patients' final satisfaction (p=0.96).

CONCLUSION

PDT is effective in the treatment of actinic cheilitis, but it is associated with a significant level of pain. Due to the persistence of dysplasia, more research needs to be done in order to define the ideal number of sessions for the effective treatment of these lesions.

Squamous Cell Carcinoma Developing after CO2 Laser Resurfacing

Background:

Skin resurfacing with the carbon dioxide (CO2) laser is currently a popular means of improving rhytides and scars and has been reported useful in the treatment for photodamaged skin, including precancerous and benign skin lesions, as well as superficial benign pigmented lesions.

Methods:

We describe a 68-year-old man who developed rapid squamous cell carcinoma (SCC) on the resurfaced areas 3 weeks following CO2 laser resurfacing.

Results:

Rapid occurrence of SCC should be considered a rare complication, and we recommend carefully considering CO2 laser resurfacing after excision of an SCC and surveying any cancer recurrences.

Conclusions:

We report a rare complication of CO2 laser resurfacing. This report suggests that additional work in this area is warranted.

Actinic cheilitis: a treatment review

All other factors being equal, the presence of actinic cheilitis, a pre-invasive malignant lesion of the lips, doubles the risk of squamous cell carcinoma developing in this anatomic area. Various forms of local ablation,immunomodulation and surgical extirpation have been proposed as therapeutic interventions. This paper critically evaluates the available medical literature to highlight the evidence-based strength of each recommended therapy for actinic cheilitis. Vermilionectomy remains the gold standard for efficacy; trichloroacetic acid application is easy and convenient, but the least efficacious overall.

Terapia fotodinâmica em dermatologia: princípios básicos e aplicações

A terapia fotodinâmica envolve a administração de uma droga fotossensibilizante e sua ativação subsequente pela luz de comprimento de onda correspondente ao espectro de absorção do fotossensibilizador. Atualmente, a terapia fotodinâmica tópica é aprovada para o tratamento de condições oncológicas cutâneas como queratoses actínicas, doença de Bowen e carcinoma basocelular superficial em diversos países do mundo. Estudos multicêntricos controlados e randomizados demonstram a alta eficácia e resultado cosmético final superior dessa modalidade terapêutica em relação aos tratamentos convencionais. Para condições cutâneas não oncológicas, como acne vulgar, verrugas virais e esclerodermia localizada, há também relatos e série de casos confirmando o potencial terapêutico da terapia fotodinâmica. O desenvolvimento de fotossensibilizantes tópicos, ácido 5-aminolevulínico (ALA) ou seu metiléster (MAL), frente aos derivados da hematoporfirina de aplicação sistêmica, permitiu um grande avanço na popularidade da TFD na dermatologia, uma vez que tanto ALA quanto MAL tópicos não induzem mais fotossensibilidade generalizada prolongada. A produção de intermediários reativos de oxigênio, como oxigênio singlet, depende da concentração, da localização do fotossensibilizante no tecido alvo, assim como da dose de luz utilizada. Tanto as lâmpadas de amplo espectro quanto os LEDs (do inglês light emitting diodes) constituem fontes de luz adequadas para que os efeitos citotóxicos da terapia fotodinâmica resultem na destruição do tumor ou seus efeitos imunomodulatórios atuem melhorando as condições inflamatórias cutâneas.

Kaposi sarcoma: a continuing conundrum

Kaposi sarcoma (KS) remains a challenge. Its classic or Mediterranean form tends to be benign. In transplant recipients it may be less so. As part of the AIDS pandemic, of which it was an original defining component, it may be life-threatening. It is due to human herpesvirus-8, which is necessary but not sufficient to produce the disease. KS has a low prevalence in the general population of the United States and United Kingdom, with an intermediate rate in Italy and Greece, and a high one in parts of Africa. In Italy, hot spots include its southern regions, the Po River Valley, and Sardinia, possibly related to a high density of blood-sucking insects. An important challenge is to treat KS patients without immunocompromising them. The potential of effective anti-herpes virus therapy and the use of sirolimus in transplantation recipients have added new opportunities for KS prevention.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be able to provide the most recent information about Kaposi sarcoma in the context in which it occurs. Its classic or Mediterranean form, its pattern in transplant recipients and others iatrogenically immunosuppressed, and its occurrence as a potentially life-threatening part of the AIDS pandemic will be stressed. Its etiology and transmission will be discussed in detail to facilitate understanding of Kaposi sarcoma and of human herpesvirus-8 infection in the general population of the United States and United Kingdom, in Italy and Greece, and in certain parts of Africa. Its therapy, including the concept of doing it without immunocompromising the patient, will be stressed. New opportunities for Kaposi sarcoma prevention will also be discussed.

Masers to magic bullets: an updated history of lasers in dermatology

Laser therapy is one of the fastest expanding and most exciting fields in dermatology. From its theoretical beginnings in Einstein's imagination, lasers have come to be used in treatments for conditions ranging from skin malignancy and acne to hirsutism and photoaging. We will briefly review the evolution of laser treatment, with a focus on the recent developments surrounding the new millennium.

Therapie von Hautmetastasen beim malignen Melanom

Malignant melanoma represents a particular challenge for dermatologists and oncologists because of its high and increasing incidence and the poor prognosis of patients with thick primary tumors (T3, T4). In advanced stages of melanoma, cutaneous and subcutaneous metastases have a special significance, as they markedly affect the patient and may lead to a limitation in quality of life. While topical therapy is possible, there are only limited clinical studies. The location, number, size and distribution of skin metastases, involvement of internal organs, age and general condition should be considered in assessing therapeutic options. Especially with solitary, easily accessible metastases, surgical excision represents the therapy of choice. Ablation using CO(2) laser is an alternative. With extensive metastases in just one extremity, isolated limb perfusion (ILP) with melphalan is an option, while multiple, smaller metastases can be irradiated. Further, several chemotherapeutic agents and immune modulators can be used topically, peri- and intralesionally.

Organ- and treatment-specific local response rates to systemic and local treatment modalities in stage IV melanoma

BACKGROUND

Metastatic melanoma shows different local response rates in organs to systemic or local treatment modalities. Whereas skin, soft tissue, lymph node and lung metastases seem to have better local response rates, the local response of metastases localized in the liver, brain and bone seems to be low.

OBJECTIVES

The organ-specific response rate, local response rate of each therapeutic measure and survival of 68 patients with stage IV disease were evaluated.

METHODS

Four hundred and ten treatment periods (1-18 per patient) in 17 different organs of 43 men and 25 women (mean age 55 years, range 19-79) with measurable, widespread, surgically incurable disease were analysed. Chemotherapy was given in 405 of 410 treatment periods with dacarbazine, fotemustine, vindesine, carboplatin and temozolomide in different schedules. Local treatment modalities comprising radiotherapy, gamma knife radiosurgery and local hyperthermia were given in 71 of 410 treatment periods.

RESULTS

Local response (complete or partial local remission) was achieved in 52 treatment periods (12.7%). When local treatment modalities, either combined with systemic therapy or not, were compared with systemic therapeutic modalities alone, a local response of 24% was achieved with local measures, compared with 10% in systemic treatment only (P = 0.003). When a spontaneous remission rate of less than 5% is considered, however, local as well as systemic treatments had a significant effect (P < 0.001). Organ-specific response rates to local therapies showed no statistically significant differences between the various organs involved. When systemic treatments without local measures were taken into account, lung metastases, cutaneous/subcutaneous metastases and adrenal metastases performed significantly better than liver metastases. When different treatment modalities were considered, there was no significant difference between the three local measures applied (radiotherapy, gamma knife radiosurgery and hyperthermia). Among the systemic therapies, dacarbazine high dose and carboplatin monochemotherapy were superior to combined regimens using fotemustine. A local response, irrespective of the mode of therapy, was significantly associated with longer survival (median 16 months) compared with no local response or local progressive disease (median 7 months; P < 0.0001). When the first treatment period of each patient was considered, local response was no longer a significant predictor.

CONCLUSIONS

The study shows that local therapeutic measures are superior in inducing a local response than systemic therapies alone. Induction of remission may be associated with longer survival. Chemotherapy, despite limited local response rates, is still statistically superior to an estimated spontaneous remission rate.

Phototherapy and malignancy: Possible enhancement by iron administration and hyperbaric oxygen

Photodynamic therapy (PDT) is a new therapeutic approach for the treatment of malignant tumors. Hyperbaric oxygen (HBO(2)) shows beneficial effects in various modalities of cancer interventions. Tumor cells tend to accumulate large amount of iron. There is interaction between tissue content of oxygen, iron, free radical production and tissue damage. Accumulation of intracellular iron is necessary for the production of oxygen radicals. HBO(2) increases tissue oxygen and hydrogen peroxide production in the cells. Malignant cells require iron, and exhibit more transferrin receptors. The photodynamic sensitization of human leukemic cells is achieved with accumulation of porphyrins stimulated by 5-aminolaevulanic acid (ALA) plus hemin. Further, a significant improvement in tumor response is obtained when PDT is delivered during hyperoxygenation. When PDT is combined with hyperoxygenation, the hypoxic condition is improved and the cell killing rate at various time points after PDT is significantly enhanced. Photosensitization with use of porphyrins is used with HBO(2) and PDT for treatment of certain tumors. PDT with ALA is used for treatment of actinic keratosis (AK). The combination of iron administration (by injection or oral rout), hemin, or transferrin, as a source for iron, HBO(2) as a source of oxygen under pressure and PDT as a source of generating free-radical tissue damage may be useful in the treatment of tumors. The possibility of combining HBO(2), iron, light and local photosensitizers to overcome skin tumors deserve extensive laboratory and clinical research work. Conclusively, iron, HBO(2), and PDT may have synergistic effect to hamper tumor cells.

5-aminolaevulinic acid photodynamic therapy in a transgenic mouse model of skin melanoma

Photodynamic therapy (PDT) is widely used to treat preneoplastic skin lesions and non-melanoma skin tumours. Studies analyzing the effects of PDT on malignant melanoma have yielded conflicting results. On the one hand, melanoma cell lines in culture as well as cell lines transplanted into experimental animals were sensitive to PDT. On the other hand, spontaneous melanomas of human patients responded poorly to most PDT regimens tested so far. Here, we analyzed effects of 5-aminolaevulinic acid (5-ALA)-based PDT on melanoma cell lines and on experimental melanomas. To mimic the clinical situation as closely as possible, metallothionein-I/ret (MT-ret) mice, a transgenic model of skin melanoma development, were used. Optimal doses of 5-ALA as well as energy doses and power densities were determined in vitro using a cell line (Mel25) established by us from a melanoma of an MT-ret transgenic mouse as well as commercially available human and mouse melanoma cell lines. Treatment with light irradiation alone had no effect. In combination with 5-ALA, however, this illumination readily induced the death of all mouse and human melanoma cell lines examined. Still, 5-ALA PDT caused only minor focal regressive changes including haemorrhages and fibrosis of MT-ret melanomas in vivo and did not significantly delay tumour growth. These results show that, even though MT-ret melanoma cells are vulnerable to 5-ALA PDT in vitro, malignant MT-ret melanomas in vivo are quite resistant to this type of therapy at doses which are highly effective in vitro.

Successful treatment of oral verrucous hyperplasia and oral leukoplakia with topical 5-aminolevulinic acid-mediated photodynamic therapy

BACKGROUND AND OBJECTIVES

Our recent studies showed that a new topical 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) protocol using a light-emitting diode (LED) light source is an effective and successful treatment modality for five cases of oral verrucous hyperplasia (OVH) and one case of verrucous carcinoma. In this study, we treated eight OVH lesions with the same topical ALA-PDT protocol to further confirm the efficacy of this protocol on OVH lesions. In addition, our recent study demonstrated an unsatisfactory clinical outcome for 24 oral leukoplakia (OL) lesions treated once a week by the same topical ALA-PDT protocol. Therefore, in this study 24 OL lesions were treated twice a week by the same protocol to compare whether the twice-a-week treatment modality could result in a better clinical outcome than the once-a-week treatment modality.

STUDY DESIGN/MATERIALS AND METHODS

In this study, 8 OVH and 24 OL lesions were treated by the same topical ALA-PDT once a week and twice a week, respectively.

RESULTS

All the former eight OVH lesions treated once a week showed complete response (CR) after 2-5 (mean, 3.8) treatments of ALA-PDT. The latter 24 OL lesions treated twice a week demonstrated CR in 8, partial response (PR) in 16, and no response in none. The present 24 OL lesions treated twice a week had a significantly better clinical outcome than the previous 24 OL lesions treated once a week (P = 0.000, chi-square test).

CONCLUSIONS

We conclude that complete regression of OVH lesions can be achieved by less than six treatments of topical ALA-PDT once a week. Although the response of OL lesions to the topical ALA-PDT is not as good as the response of OVH lesions to the same therapy, all OL lesions can have at least PR after eight treatments with the topical ALA-PDT twice a week. In addition, OL lesions treated twice a week have a significantly better clinical outcome than OL lesions treated once a week.

Therapeutic options for human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus-related disorders

Human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus infection is associated with three proliferative disorders in immunocompromised patients - Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. These disorders often develop in patients with advanced AIDS who present a number of therapeutic challenges, underscoring the importance of continuing efforts dedicated to basic and clinical research in this field. In the era of highly active antiretroviral therapy, the incidence of AIDS and Kaposi's sarcoma has considerably decreased, presumably due to enhanced anti-Kaposi's sarcoma-associated herpesvirus immune responses, whereas the situation with primary effusion lymphoma and multicentric Castleman's disease is more complex. Based on advances in the understanding of Kaposi's sarcoma-associated herpesvirus-related disorders and availability of antiretroviral agents, current and future therapeutic approaches will be discussed.

Locoregional cutaneous metastases of malignant melanoma and their management

The correct classification of locoregional metastases of malignant melanoma to skin is central to the planning of treatment. Local recurrence means persistence of neoplastic cells at the local site by virtue of incomplete excision of the primary melanoma. Standard treatment is excisional surgery. In contrast, locoregional metastases of malignant melanoma (satellites, in-transit metastases) are metastases around a primary melanoma or between a primary melanoma and regional lymph nodes. They represent intralymphatic or hematogenous spread of neoplastic cells. We present a variety of available treatment options and discuss especially topical imiquimod as a novel approach for the palliative treatment of locoregional cutaneous melanoma metastases in selected patients.

Selectivity of the photosensitiser Tookad for photodynamic therapy evaluated in the Syrian golden hamster cheek pouch tumour model

The response to photodynamic therapy (PDT) with the photosensitiser (PS) Tookad® was measured in the Syrian hamster cheek pouch model on normal mucosae and chemically induced squamous cell carcinoma. This PS is a palladium-bacteriopheophorbide presenting absorption peaks at 538 and 762 nm. The light dose, drug dose and drug injection-light irradiation times (DLI), ranging between 100 and 300 J cm⁻², 1–5 mg kg⁻¹ and 10–240 min respectively, were varied and the response to PDT was analysed by staging the macroscopic response and by the histological examination of the sections of the irradiated cheek pouch. A fast time decay of the tissular response with drug dose of 1–5 mg kg⁻¹ was observed for DLI ranging from 10 to 240 min and for light doses of 100–300 J cm⁻² delivered at a light dose rate of 150 mW cm⁻². A significantly higher level of tissular response was observed for squamous cell carcinoma compared to normal tissue. Nevertheless, the threshold level of the drug–light dose for a detectable response was not significantly different in the tumoral vs normal tissue. The highest response at the shortest DLIs and the absence of measurable response at DLI larger than 240 min at light dose of 300 J cm⁻² and drug dose of 5 mg kg⁻¹ reveals the predominantly vascular effect of Tookad®. This observation suggests that Tookad® could be effective in PDT of vascularised lesions.

Photodynamic therapy of virus-associated epithelial tumours of the face in organ transplant recipients

PURPOSE

The benefit for organ recipients is still counteracted by the side effects of immunosuppression. Among other effects, there is a 50-250 times increased risk of developing malignant skin tumours. Because these malignomas are known to develop particularly aggressivly, there is a special need for an efficient therapy. Here we demonstrate the treatment response to aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) in these patients.

METHODS

Five organ recipients with multiple tumours of the face were multifocally treated with ALA-PDT (32 tumours in all). After topical application of ALA using a thermogel, irradiation was done with a 635 nm diode laser (Ceralas 635, Biolitec, Jena, Germany). After intervals of 2 weeks, 4 weeks, and 12 weeks, therapeutic efficacy was assessed.

RESULTS

There was complete remission in 24 tumours (75%). In six tumours (18.8%) a second or third PDT session was necessary for complete clinical remission. In two tumours (5.6%, invasive squamous cell carcinomas) the lesions were refractory to PDT.

CONCLUSIONS

ALA-PDT is a valuable therapeutic alternative for the treatment of multifocal skin tumours in organ-transplanted patients. Furthermore, we see a growing role of ALA-PDT also for patients with frequently relapsing tumours of the skin with known genetically determined tumourigenesis (Gorlin-Goltz syndrome).

Evaluation of the photosensitizer Tookad for photodynamic therapy on the Syrian golden hamster cheek pouch model: light dose, drug dose and drug-light interval effects

We have evaluated the efficacy of the new photosensitizer (PS) Tookad in photodynamic therapy (PDT) in vivo. This PS is a palladium-bacteriopheophorbide presenting absorption peaks at 762 and 538 nm. The light dose, drug dose and drug injection-light irradiation interval (DLI), ranging between 100 and 300 J/cm2, 1 and 5 mg/kg and from 10 to 240 min, respectively, were varied, and the response to PDT was analyzed by staging the macroscopic response and by the histological examination of the sections of the irradiated cheek pouch. The level of PDT response, macroscopically and histologically, shows a strong dependence on the DLI, light dose and drug dose at the applied conditions in the normal hamster cheek pouch. A decay of the tissular response with increasing DLI is observed corresponding to a time of half-maximum response ranging from 10 to 120 min, depending on drug dose and light dose. The tissues affected at the lowest doses are predominantly the vascularized diffuse connective tissue situated between the inner and outer striated muscle (SM) layers as well as these muscle layers themselves. The highest response at the shortest DLI and the absence of a measurable response at DLI longer than 240 min at 300 J/cm2 and drug dose of 5 mg/kg are characteristics of a predominantly vascular effect of this PS. This observation suggests that Tookad could be effective in PDT of vascularized lesions or pathologies associated with the proliferation of neovessels.

Management of lentigo maligna and lentigo maligna melanoma: Seminars in surgical oncology

Lentigo maligna (LM) and lentigo maligna melanoma (LMM) represent a character, histogenetic subclass of melanocytic malignancies. They often present with a prolonged phase of slow growth but once invasion has occurred, the prognostic features are identical to all other melanomas. These lesions occur primarily on the head and neck where they evolve from areas of pigmented staining to the more typical features identifiable with malignant melanomas on other skin surfaces. The treatment options and recent advances in management are reviewed.

Intratumoral cisplatin/adrenaline injectable gel for the treatment of patients with cutaneous and soft tissue metastases of malignant melanoma

Local therapies have been highly effective in the treatment of melanoma. The objective of this study was to evaluate the use of a novel intralesional chemotherapy - cisplatin/adrenaline injectable gel - for the treatment of refractory or recurrent cutaneous and soft tissue melanoma metastases. The gel is injected directly into the lesion and delivers high concentrations of cisplatin at the injection site, where it is retained for extended periods, with little systemic exposure. A total of 28 patients with refractory or recurrent melanoma were enrolled in this open-label, multicentre study. Of these, 25 patients with 244 lesions were evaluable for efficacy. Lesions were injected with 0.5 ml (2 mg cisplatin + 0.05 mg adrenaline) of gel/cm(3) of tumour. Patients received up to six weekly treatments within an 8 week period. The objective response rate (complete responses [CRs] plus partial responses [PRs]) for all the tumours treated (1-72 per patient) was 53% (130 out of 244; 114 CRs, 16 PRs). The response rate for the target tumours (i.e. each patient's single, most symptomatic, largest or most threatening tumour) was 44%. The median response duration for all tumours was 347 days (range 30-783 days) and median number of treatments per tumour was five (range one to twelve). Systemic toxicity was negligible; local adverse reactions such as erythema, necrosis or pain occurred frequently, but were easily managed in most cases. In conclusion, cisplatin/adrenaline injectable gel was well tolerated, easy to administer, and effective in treating metastatic melanoma confined to the skin or soft tissues.

Photosensitizing effect of protoporphyrin IX in pigmented melanoma of mice

No fluorescence of protoporphyrin IX (PpIX) was measured using a fiber optic probe in pigmented B16F10 melanoma in mice after topical application of 5-aminolevulinic acid methylester (ALA-Me). However, chemical extraction of tissues excised from mice after intratumoral administration of ALA-Me or its parent compound ALA revealed that this tumor had the capability to produce PpIX. Small amounts of endogenous porphyrins, mainly PpIX, were found in the melanoma not treated with these drugs. Topical application of ALA-Me followed by exposure with laser light (633nm) delayed the growth of the tumors slightly. Light alone also had a significant effect on the tumor growth.