Photodynamic Therapy for the Treatment of Skin Tumors

Abstract

Photodynamic therapy (PDT) is a novel noninvasive cancer therapy. PDT with topical 5-aminolevulinic acid (ALA) has been used to treat skin tumors in dermatology. Topically applied ALA converted to photosensitizing protoporphyrin IX endogenously in tumor tissues. PDT is a well-establised treatment modality which has mainly shown to be effective for actinic keratoses, Bowen′s diseases (squamous cell carcinoma in situ) and superficial basal cell carcinomas. We observed a complete response after one or two sessions of PDT for 82 of 98 actinic keratoses, 20 of 35 Bowen′s diseases, and 3 of 4 superficial basal cell carcinomas.PDT has been used for the treatment of extramammary Paget′s diseases and mycosis fungoides. Photodynamic diagnosis allows the delineation of clinically ill-defined tumors and the detection of tumor relapse or new tumors which were not clinically detectable. PDT in dermatology is a convenient, non-invasive treatment with excellent cosmetic outcomes without surgical scars. More research is required to determine the exact parameters optimal for the treatment of each tumors.