Photodynamic therapy for nonmelanoma skin cancer.

Photodynamic therapy (PDT) involves the administration of a photosensitizing drug and its subsequent activation by light at wavelengths matching the absorption spectrum of the photosensitizer. Because the skin is readily accessible to light-based therapies, PDT with systemic and particularly with topical agents has become important in treating cutaneous disorders. Topical PDT is indicated for treating actinic keratosis, superficial or thin non-melanoma skin cancer, including some cases of nodular basal cell carcinoma, and some cutaneous lymphomas. Advantages of aminolevulinic acid/methyl aminolevulinate PDT include the possibility of simultaneous treatment of multiple tumors and large surface areas, good cosmesis, and minimal morbidity, such as bleeding, scarring, or infection.