Treating patients with actinic keratosis (AK) with half-time illumination photodynamic therapy (PDT) is as effective as complete time illumination PDT, according to study results published in the Journal of the European Academy of Dermatology and Venereology.
Researchers compared the efficacy, tolerability, and safety of conventional full-time PDT with half-time PDT in patients with AK. Adults with >5 grade I or II AK lesions completed assessments including demographic information, AK assessments, and quality-of-life questionnaires at baseline. Participants then completed a treatment of methyl aminolevulinic acid and then a full-time PDT protocol of 8 minutes on half of their face and a half-time PDT protocol of 4 minutes on the other half of their face. The patients completed evaluations of pain, adverse effects, and symptoms after treatment and completed follow-up evaluations at 3 and 6 months after PDT.
Of the 29 participants included in the study, 75.8% were men, the mean age was 76.9±6.33 years, the mean phototype was 2.07±0.37, and the mean number of lesions was 26.69±7.81. In total, 385 lesions were treated with full-time PDT and 389 lesions were treated with half-time PDT. At 3 months, 85% of the full-time PDT had a complete response and 82% of the half-time PDT had a complete response (P =.573). At 6 months, 70% of the patients who received full-time PDT had a complete response and 65% of the half-time PDT group had a complete response (P =.433).
During illumination, the visual analog scale for pain had a mean score of 6.41±1.66 for the full-time PDT group and a mean score of 5.59±1.48 for the half-time PDT group (P =.0). Overall, the mean scores on the quality-of-life questionnaires improved from 4.48±3.45 at baseline to 1.28±1.42 at 3 months (P <.05). No significant differences were found for erythema, edema, crust, and blisters 24 hours after treatment between the 2 therapy protocols.
Limitations of this study included the short-term follow-up time frame, adverse events reported by the patients, and the non-inclusion of aesthetic evaluations in the analysis.
The researchers concluded, “Illumination half time with the conventional PDT protocol with 2 h[ours] of incubation of [methylaminolevulinic acid] is as effective as the complete time with lower pain and the same side-effects.”
Fernández-Guarino M, Fonda Pascual P, Lizuain Gomez P, Harto Castaño A, Jaén Olasolo P. Split-face study comparing conventional MAL photodynamic therapy in multiple actinic keratosis with complete time vs. half-time red light LED conventional illumination [published online March 13, 2019]. J Eur Acad Dermatol Venereol. doi:10.1111/jdv.15566