Methyl aminolevulinate: actinic keratoses and Bowen's disease.

Topical photodynamic therapy (PDT) using the methyl ester of 5-aminolaevulinic acid (MAL) is an effective therapy for actinic keratoses and Bowen's disease. Thin and moderate thickness facial actinic keratoses respond best, with clearance rates equivalent or superior (depending on protocol) to current therapy, and with notably superior cosmetic outcome. Patients with areas of field cancerization and organ transplant recipients may particularly benefit from topical MA-PDT. The response rate of Bowen's disease to MAL-PDT is also at least equivalent to cryotherapy and 5-fluorouracil, again with superior cosmesis. Patients with large or multiple lesions of Bowen's disease or those in whom standard therapy, including surgery, is relatively contraindicated may particularly benefit from PDT.