PHOTODYNAMIC THERAPY OF SUPERFICIAL BASAL-CELL CARCINOMAS USING TOPICAL 5-AMINOLEVULINIC ACID IN A NANOCOLLOID LOTION

Background: Photodynamic therapy (PDT) of superficial basal cell carci nomas using endogenous protoporphyrin IX generated by topically applie d 5-aminolevulinic acid (5-ALA) is an innovative and clinically encour aging approach. Objective: This paper reports on the first results of an ongoing clinical study on photodynamic therapy of 55 basal cell car cinomas in 19 patients. Methods: Because of the chemical instability o f 5-ALA, a novel nanocolloid lotion was developed. This formulation wa s applied to the lesions under occlusive dressing 6 h before irradiati on with visible light from an unfiltered halogen lamp. Light induced f luorescence was used to ascertain the superficial extension of the tum ors. The response to the therapy was assessed by visual inspection and in 13 patients also by biopsies. Results: After a single treatment, 4 7 (85%) basal cell carcinomas showed a complete response at a follow-u p time of at least 6 months. For the remaining 8 (15%) lesions, a part ial response was observed, indicated by a marked reduction of the tumo r size. The treatment modality without local anesthetics was well tole rated by all patients, with only slight discomfort during light irradi ation. Conclusion: Our results indicate that 5-ALA-PDT with our novel formulation, a nanocolloid lotion, is a highly effective and convenien t therapy for the treatment of superficial basal cell carcionomas. Its use in the treatment of nodular tumors needs further investigations.