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

Abstract

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 300 mW/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.