The Therapeutic Effect of Photodynamic Therapy with Aminolevulinic Acid Topical Solution and Blue Light for Actinic Keratosis

Background: Actinic keratoses (AKs) are precancerous lesions that are treated with local liquid nitrogen cryotherapy, topical fluorouracil or topical chemotherapeutic agents. Photodynamic therapy (PDT) with various kinds of light sources has recently been tried for treating actinic keratoses. There have been no studies in the Korean literature about the effectiveness of aminolevulinic acid (ALA)-PDT combined with blue light for treating actinic keratoses. Objective: We examined the safety and efficacy of PDT (using topical 20% ALA solution and blue light) for the treatment of actinic keratoses. Methods: Twenty five AKs lesions of 17 patients were enrolled in the study. They were prepared with the application of topical 20% ALA solution for 2 hours and this was followed by exposure to 4175 nm blue light at 10 J/. The lesions were assessed at 48 hours and 2 and 4 weeks following PDT. Those target lesions remaining at week 4 were re-treated. Skin biopsies were done at 8 weeks to evaluate the response to ALA-PDT. Results: Complete remissions were achieved for 64.0% of the AKs lesions after 2 treatment sessions. Only two patients suffered from a stinging sensation when exposed to the light therapy. Conclusion: Topical ALA-PDT with using a blue light source could be an effective treatment modality for actinic keratoses.