Current methods for photodynamic therapy in the US: comparison of MAL/PDT and ALA/PDT.

There is some debate regarding the rate of progression of actinic keratosis (AK) into squamous cell carcinoma (SCC).1-4 However, it is clear that treatment for AK lesions is warranted. Results from numerous studies with aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) photodynamic therapy (PDT) for the treatment of AKs, SCC, and Bowen's disease show high rates of clearance for these lesions. MAL/PDT provides similar efficacy to ALA/PDT with the benefits of shorter incubation times according to the approved FDA labeling, greater selectivity, reduced pain during and immediately following therapy, and fewer systemic side effects. Cosmetic outcomes are better with PDT than with cryosurgery or excisional surgery. A number of case reports show efficacy with ALA/PDT and MAL/PDT for acne, photorejuvenation, and other off-label indications. Side effects with PDT tend to be mild to moderate and transient in nature. Overall, ALA/PDT and MAL/PDT are effective for a variety of skin diseases and conditions. MAL/PDT provides some advantages over ALA/PDT.