Topical photodynamic therapy in the treatment of basal cell carcinoma in Singaporean Chinese patients.

BACKGROUND: Topical photodynamic therapy has been used for the treatment of superficial and nodular basal cell carcinomas, with varying cure rates. AIMS: This study aims to evaluate the effectiveness of topical photodynamic therapy in the treatment of superficial and nodular basal cell carcinomas in Asian patients treated at the National Skin Centre, Singapore. MATERIALS AND METHODS: A retrospective analysis of Asian patients with histologically confirmed basal cell carcinomas and treated with photodynamic therapy was performed. RESULTS: Eight Chinese patients, with an equal gender distribution and mean age of 83.4 years were included. Five of eight basal cell carcinomas were superficial while the remaining three were nodular. The basal cell carcinomas were located in the head and neck in seven patients. The overall clearance rate at 3 months was 87.5% while the clearance rate for superficial and nodular basal cell carcinomas was 100% and 66.6% respectively at 3 months. At 12 months, the overall clearance rate was 85. 7%. LIMITATIONS: This is a retrospective analysis with small patient numbers. CONCLUSIONS: In this small series of eight Asian patients, topical photodynamic therapy has been shown to be effective and generally well-tolerated in the treatment of basal cell carcinomas, particularly of the superficial subtype. However, larger studies are needed to evaluate its overall efficacy in Asian patients.

Efficacy of red light alone and methyl-aminolaevulinate-photodynamic therapy for the treatment of mild and moderate facial acne.

BACKGROUND: Photodynamic therapy (PDT) has been shown to be an effective alternative for acne. However, there is little information comparing the efficacy of red light alone and methyl aminolaevulinate (MAL)-PDT. AIMS: To compare the efficacy and tolerability of red light alone and MAL-PDT in patients with mild to moderate facial acne. METHODS: Thirty six patients with mild to moderate acne were enrolled. Eighteen patients recieved MAL-PDT and 18 received red light alone in two sessions, 2 weeks apart. Acne grade and lesion counts were assessed by blinded evaluators at baseline, 2, 4 and 10 weeks. RESULTS: At week 2, clinical improvement from acne grade II-IV to 0-I was observed in 82.3% of MAL-PDT group and 14.2% of red light alone group. Red light alone group had a gradual clinical improvement over time with a 77% response at week 10. In contrast, MAL-PDT group had a rapid clinical improvement with total response at week 10. Both treatments were significantly effective for improving acne lesions. However, MAL-PDT group had a greater response (P < 0.001). Histologically, decreased amounts of sebocytes and lipids along with atrophic sebaceous glands were observed after MAL-PDT. CONCLUSION: MAL-PDT has a quicker onset of action with a higher response than red light alone. MAL-PDT may induce a reduction in the size of the sebaceous glands and then long-term acne remission.

Topical photodynamic therapy with methylaminolevulinate for the treatment of actinic keratosis and reduction of photodamage in organ transplant recipients: a case-series of 16 patients.

BACKGROUND: Organ transplant recipients (OTR) are at high risk of developing cutaneous neoplasms. Topical photodynamic therapy (PDT) has been used for the treatment of actinic keratosis (AK) in OTR. AIMS: The objective was to evaluate the efficacy of PDT with methylaminolevulinate (MAL) in the treatment of facial AK in OTR. As a secondary objective, we wanted to evaluate the usefulness of topical PDT in the reduction of photodamage in OTR. METHODS: A prospective, single center, single arm study was made. 16 OTR were included. Topical PDT was applied for 1 or 2 cycles depending on the patient's characteristics. An evaluation of AK was made at visits pre-treatment, at 12 weeks and at 24 weeks. Photodamage was measured with multispectral image technique (SkinCare). RESULTS: A complete response rate of 100% was achieved for AK in all patients; it persisted without change at 12 and 24 weeks of follow-up. 62.5% of patients improved their photodamage as measured by SkinCare®, but this result was not statistically significant (P = 0.12). All patients had high level of satisfaction at the end of the therapy. CONCLUSIONS: MAL-PDT is an effective therapy for the treatment of AK in OTRs. It can reduce photodamage in this group of patients, but these results were not statistically significant.

Efficacy of topical photodynamic therapy for keratoacanthomas: a case-series of four patients.

Topical photodynamic therapy (PDT) is an excellent treatment option for various non-melanoma skin cancers and precancerous lesions, including actinic keratosis, Bowen's disease, and basal cell carcinoma. The clinical use of PDT includes a broad range of neoplastic, inflammatory, and infectious skin diseases. There is also anecdotal evidence suggesting the efficacy of PDT for the treatment of keratoacanthomas (KA). We report a case-series of four patients with solitary KA confirmed by histology, treated with topical PDT with methylaminolevulinic acid (MAL) cream. After three sessions of PDT, the lesions completely disappeared. There was no evidence of recurrence and excellent cosmetic outcome was achieved after three years of follow-up. Topical photodynamic therapy with MAL can be a therapeutic alternative for KA with good clinical and cosmetic outcomes.

Pharmacokinetic of ALA and h-ALA induced porphyrins in the models Mycobacterium phlei and Mycobacterium smegmatis.

Photodynamic inactivation (PDI) of bacterial strains presents an attractive potential alternative to antibiotic therapies. Success is dependent on the effective accumulation in bacterial cells of photochemical substances called photosensitizers, which are usually porphyrins. It is also important to know the distribution of the photosensitizer in bacteria at the microscopic level. The present results examine the accumulation of photosensitizers by Mycobacterium phlei and Mycobacterium smegmatis, which serve as models for the important pathogens Mycobacterium tuberculosis, Mycobacterium leprae and Mycobacterium bovis. The kinetics of porphyrin synthesis after treatment with the precursors ALA and h-ALA were studied. The goal was to describe the biosynthesis and the pharmacokinetics of sensitizers in both bacterial strains using fluorescence microscopy and spectroscopy. We could show that both Mycobacterium strains enrich porphyrins after ALA and h-ALA administration detected by fluorescence peaks at about 620nm. By HPLC analyses the major porphyrin could be identified as coproporphyrin. In the future we will apply the new knowledge in in vitro and in vivo experiments to strains of M. tuberculosis, M. leprae and M. bovis and examine cell destruction by PDI.