Fractional carbon dioxide laser-assisted photodynamic therapy for patients with actinic keratosis.

Background/purpose A relatively long incubation time is needed for photosensitizer absorption in conventional photodynamic therapy (PDT) for actinic keratosis (AK). The use of ablative CO2 fractional lasers (AFXLs) to increase drug delivery could shorten the incubation time. Here, we aimed to compare the efficacy between AFXL-assisted PDT with a short incubation time and conventional PDT for AK. Methods Patients with histopathologically confirmed facial AK were randomly divided into two groups. The lesions were histopathologically classified into grades I–III. In the AFXL-assisted PDT group, an ablative fractional laser was used for pretreatment, prior to the application of methyl aminolevulinate, with an incubation time of 90 min. Irradiation was performed with a 630-nm light-emitting diode. In the conventional PDT group, the incubation time was 180 min. All the patients received two rounds of PDT at 2-week intervals and underwent clinical or histological evaluation at 10 weeks after the first PDT course. Results Twenty-two patients underwent conventional PDT and 24 patients underwent AFXL-assisted PDT. Thirty-four AKs were included in the conventional PDT group, and 35 AKs were included in the AFXL-assisted PDT group. The clearance rate was 64.7% in the conventional PDT and 71.4% in the AFXL-assisted PDT group; no significant differences in the clearance rate were noted between the groups (P = 0.55). The clearance rates for each grade also did not significantly differ between the two groups. Conclusions The use of AFXL before PDT reduced the incubation time, but yielded similar treatment efficacy as compared to conventional PDT.