Photodynamic therapy using a methyl ester of 5-aminolevulinic acid in recurrent Paget's disease of the vulva: A pilot study

Abstract

Objective. In the past, treating vulvar Paget's disease through surgery has resulted in a high recurrence rate of the disease. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5 ALA) is an effective treatment for some conditions such as Bowen's disease, subsets of basal cell carcinomas and vulvar carcinoma. Methyl 5-aminolevulinate (MAL) is an ester of 5 ALA that seems to be more effective and produces fewer side effects than 5 ALA. This paper outlines a pilot study designed to test the feasibility of using MAL-PDT in the treatment of recurrent vulvar Paget's disease. Methods. 5 MAL-PDT was applied for 3 h and than irradiated with red-light (620 nm) using a total light dose of 37 J/cm 2 for a period of 10 min. Patients taking part in the study were treated once every 3 weeks, for a total of three treatments. Vulvar biopsies were obtained before and 1 month after the PDT-treatment. Results. Seven patients were enrolled in the study. Four cases had a complete clinical response, and this was pathologically confirmed in two of the cases. The cosmetic outcome was acceptable and the treatment was well tolerated. All the patients developed local edema and mild local pain, controlled with non-steroidal antiinflammatory drugs (NSAIDS). One patient experienced severe pain and a mild local phototoxicity reaction. Conclusions. MAL-PDT is a feasible treatment and seems to offer a reliable strategy in the control of vulvar Paget's disease and of its symptoms.