Modified topical photodynamic therapy of superficial skin tumors, utilizing aminolevulinic acid, penetration enhancers, red light, and hyperthermia

BACKGROUND. Photodynamic therapy (PDT) is a noninvasive selective therapy for a specific group of skin tumors. OBJECTIVE. In this study we used a modified topical medication in which ethyleneamine tetra acetic acid (EDTA) and dimethylsulphoxid (DMSO) were added to 5-aminolevulinic acid 20% (ALA) followed by exposure to a novel high output light source emitting red and infrared irradiation. METHODS. ALA 20%-EDTA 2%-DMSO 2% in a water in oil cream base wits applied to the tumors. After 12 hours the tumor was exposed to red (585-720 nm; 150 mW/cm(2)) and near infrared irradiation (1.25-1.6 mm; 50 mW/cm(2)) for 10-15 minutes by the VersaLight incoherent filtered light source. RESULTS. Complete responses were achieved after one to three ALA-PDT treatments in 26/31 lesions of superficial or small nodular basal cell carcinoma (BCC) (84%), and in Jour of five in superficial squamous cell carcinoma (SCC) (80%). Complete clearance was achieved in one patient with Bowen's disease of the penis. CONCLUSIONS. Topical PDT utilizing ALA 20%-EDTA 2%-DMSO 2% as the photosensitizer and VersaLight as the light source is a noninvasive, nearly painless treatment with excellent therapeutic and cosmetic results. Our data show the efficiency of this therapy for patients with certain subtypes of BCC, SCC, and Bowen's disease. (C) 1998 by the American Society for Dermatologic Surgery, Inc.