Split-face study comparing conventional MAL photodynamic therapy in multiple actinic keratosis with complete time vs. half-time red light LED conventional illumination.

BACKGROUND: Conventional photodynamic therapy (PDT) with methylaminolevulinic acid (MAL) and daylight PDT have demonstrated similar efficacy in the treatment of actinic keratosis (AK). The reason for the use of daylight is to reduce pain during illumination but daylight has the limitation of the weather conditions. The difference in the doses of red light applied between these two methods suggests that an intermediate dose with red light conventional illumination could be effective in PDT of AK.

OBJECTIVE: To compare the efficiency of conventional MAL-PDT with half-time conventional red light illumination in patients with multiple AK.

MATERIAL AND METHODS: Adult patients with more than five symmetrically distributed AK were selected. After randomization, one area was treated with conventional PDT (Aktilite® , 630 nm, 37 J/cm2 , 8 min), while the contralateral was illuminated half time (Aktilite® , 630 nm, 37 J/cm2 , 4 min). Patients evaluated pain in each different side. Patients were evaluated at baseline, 3 and 6 months after PDT treatment by a blinded dermatologist. A questionnaire to be done at home 24 h after completing treatment was deliver to the patients to evaluate any side-effects.

RESULTS: A total of 774 lesions were treated, 385 with conventional PDT and 389 with half-time PDT (P > 0.05). Conventional PDT was 85% of complete response of AK (327/385) at 3 months, and half-time PDT was 82% (319/389). At 6 months, conventional PDT was 70% (268/385) of complete response and half-time PDT was 65% (252/389). Pain during illumination was significantly lower in the VAS with the half-time protocol with a mean of 5.59 (SD 1.48) vs. 6.41 (SD 1.66) in conventional PDT. No difference in adverse effects was found between protocols.

CONCLUSION: Conventional PDT with half-time illumination in multiple actinic keratosis is as effective as complete time illumination and decreased pain significantly.