Photodynamic therapy of superficial basal cell carcinomas using topical 5-aminolevulinic acid in a nanocolloid lotion

Photodynamic therapy (PDT) of superficial basal cell carcinomas using endogenous protoporphyrin IX generated by topically applied 5-aminolevulinic acid (5-ALA) is an innovative and clinically encouraging approach.

This paper reports on the first results of an ongoing clinical study on photodynamic therapy of 55 basal cell carcinomas in 19 patients.

Because of the chemical instability of 5-ALA, a novel nanocolloid lotion was developed. This formulation was applied to the lesions under occlusive dressing 6 h before irradiation with visible light from an unfiltered halogen lamp. Light-induced fluorescence was used to ascertain the superficial extension of the tumors. The response to the therapy was assessed by visual inspection and in 13 patients also by biopsies.

After a single treatment, 47 (85%) basal cell carcinomas showed a complete response at a follow-up time of at least 6 months. For the remaining 8 (15%) lesions, a partial response was observed, indicated by a marked reduction of the tumor size. The treatment modality without local anesthetics was well tolerated by all patients, with only slight discomfort during light irradiation.

Our results indicate that 5-ALA-PDT with our novel formulation, a nanocolloid lotion, is a highly effective and convenient therapy for the treatment of superficial basal cell carcinomas. Its use in the treatment of nodular tumors needs further investigations.