Single-center real-world treatment outcomes of ablative fractional laser-assisted photodynamic therapy for actinic keratosis.

Abstract

Among various treatment modalities of actinic keratosis (AK), ablative fractional laser-assisted photodynamic therapy (fractional PDT) has shown higher efficacy despite shorter incubation time. However, there are lack of real-world studies on the therapeutic response of ablative PDT for AK and the factors that can predict the therapeutic response. The aim of this study was to analyze the association between clinical characteristics and treatment outcomes of fractional PDT. One hundred fifty-six patients who were histologically diagnosed with AK and treated with fractional PDT were retrospectively reviewed. The Kruskal-Wallis test was used to compare treatment session differences according to grades. In multivariate analysis, the grade 2 category tended to be more clinically nonresponders than the grade 1 (OR, 5.17; 95% CI, 1.011-26.439; p=.048) and the group treated four or more times with ablative fractional laser-assisted PDT were more likely to show no response compared with the single treatment session group (OR, 8.78; 95% CI, 1.355-56.874; p=.023). Treatment sessions were significantly lower in grade 1 (1.72 ± 0.63, mean ± SD) when compared to grades 2 and 3, respectively (2.17 ± 0.76; 2.60 ± 1.60, mean ± SD). Recurrence was highest in grade 2, and most of them occurred after 1 year. On average, two treatment sessions are sufficient for AK lesions, but the thicker the lesion, the more treatment sessions may be required. Although there are relatively smaller number of grade 3 patients were included, recurrence was more frequent in higher grade of AK category, which needs special attention to thicker lesions.