Nonablative fractional photothermolysis for facial actinic keratoses: 6-month follow-up with histologic evaluation

Background: A number of epidermal and papillary dermal skin conditions can be treated safely and effectively with fractional photothermolysis (FP). Objective: We sought to evaluate the effectiveness of FP with a 1550-nm fractionated erbium-doped fiber laser for the treatment of facial actinic keratoses (AKs). Methods: Fourteen men, ages 59 to 79 years, underwent 5 laser treatments (2- to 4-week intervals) at an energy fluence of 20 to 70 mJ and treatment level of 11 (8-10 passes), corresponding to 32% to 40% surface area coverage. AK counts and photographs were taken at baseline, before each treatment, and at 1-, 3-, and 6-month follow-ups after the last treatment. Biopsies were performed at baseline and at the 3-month follow-up. The clinical improvement of the actinic lesions was evaluated by a dermatologist using digital photography and lesion counts at all 3 follow-up visits. Results: The AK count for each patient was reduced on average by 73.1% (67.5%-77.7%) at the 1-month, 66.2% (60.0%-71.5%) at the 3-month, and 55.6% (43.9%-64.8%) at the 6-month follow-up visit. Excluding two cases, all biopsy specimens (baseline and at the 3-month follow-up) were positive for histologic features of AK and/or squamous cell carcinoma. Limitations: This study is limited by a small number of patients; therefore further clinical studies are warranted. Conclusions: FP decreases the number of clinical AKs; however, posttreatment biopsy specimens indicate the histologic persistence of AKs (epidermal tumors). FP is not an adequate single-treatment modality for AKs.