Photodynamic Therapy with Ablative Carbon Dioxide Fractional Laser in Treatment of Actinic Keratosis

BACKGROUND Recently, photodynamic therapy (PDT) has been shown to be an effective first-line treatment for actinic keratosis (AK). However, a major limitation of PDT is the long incubation time required to allow penetration of the photosensitizer. OBJECTIVE The aim of this study was to assess if pretreatment with an ablative carbon dioxide (CO2) fractional laser can reduce the incubation time of the photosensitizer. METHODS Initially, 29 patients with a total of 34 AK lesions were treated with an ablative CO2 fractional laser at Ajou University Hospital between January and December 2010. Immediately after the laser treatment, topical 20% 5-aminolevulinic acid or methyl-aminolevulinate was applied to the AK lesions and incubated for 70 to 90 minutes. Then, the treated areas were illuminated with a red light source. Improvement was clinically or histologically assessed eight weeks after the treatment. RESULTS In spite of the short incubation time, 24 lesions (70.6%) showed a complete response (CR) within three sessions of PDT (10 lesions a clinical CR and 14 lesions a clinical/histological CR). There were no significant side effects associated with the combination of ablative CO2 fractional laser and PDT. CONCLUSION Ablative CO2 fractional laser may be considered an additional treatment option for reducing the incubation time of the photosensitizer in PDT.