Photodynamic therapy in the management of nonmelanoma skin cancers

Photodynamic therapy involves the use of light to activate a photosensitizer, localized in diseased skin, resulting in the formation of cytotoxic reactive oxygen species. Topical photodinamic therapy (PDT) is used to treat nonmelanoma skin cancers, such as actinic keratoses, Bowen's disease, and basal cell carcinoma, superficial as well as nodular. This article presents up-to-date, practical recommendations on the use of topical PDT using 5-aminolevulinic acid or methyl aminolevulinate for the treatment as well as prevention of nonmelanoma skin cancers. A systematic literature review was conducted using MEDLINE, and recommendations were made on the basis of the quality of evidence for efficacy, tolerability and cosmetic outcome. Most authors concluded that topical PDT is highly effective in the treatment of actinic keratoses, Bowen's disease, superficial and thin nodular basal cell carcinomas, with cosmetic typically superior to that achieved with existing standard therapies. Photodynamic therapy may also be a means of preventing certain nonmelanoma skin cancers in immunosuppressed patients.