Pretreatment with ablative fractional carbon dioxide laser improves treatment efficacy in a synergistic PDT protocol for actinic keratoses on the head

Background: A recently proposed synergistic photodynamic therapy protocol (s-PDT) combining advantages of both conventional- and daylight-PDT proved to be an effective and almost painless treatment for patients with actinic keratoses (AKs). This study investigated the safety and efficacy of an additional ablative fractional CO2-laser (AFXL) pretreatment.

Methods: 28 patients with AKs on the head received s-PDT using 5-aminolevulinic acid. AFXL pretreatment was conducted using the following parameters: pulse energy 8 mJ, spot density 50 spots/cm², power 30 W, beam size 4-18 mm. Outcome was assessed by AK area and severity index (AKASI) and lesion count (LC) before and 3 months after treatment. Safety was monitored by blood pressure and pulse measurements. Intensity of pain was determined by use of a visual analog scale (VAS).

Results: Most patients (96.4 %) showed a significant AKASI reduction (P < 0.0001) 3 months after PDT (median AKASI 1.6 [0-2.4]) compared to baseline (5.3 [4-7.75]). Median reduction rate was 75.5 % (61.3 %-100 %). Eleven patients (39.3 %) achieved AKASI 100, three (10.7 %) AKASI 75 and ten (35.7 %) AKASI 50. Blood pressure and pulse did not change significantly throughout treatment. Median VAS for pain during irradiation was 0 (0-0), 0 (0-2) and 0 (0-2) at the beginning, in the meantime and at the end, respectively. Compared to data without AFXL pretreatment, this study showed significantly higher AKASI and LC reduction rates (75.5 % vs. 63.7 % [P = 0.023] and 91.3 % vs. 80.4 % [P = 0.043]).

Conclusions: S-PDT with AFXL pretreatment represents a safe and almost painless treatment for patients with AKs on the head and improves treatment efficacy.