Modified Painless Photodynamic Therapy for Actinic Keratosis in China

Significance Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for actinic keratosis (AK). However, the pain during illumination usually caused patient to discontinue PDT treatment and resulted lower efficacy. Previous study showed modified painless PDT (M-PDT) with short ALA incubation time and longer irradiation time can reduce pain and preserve the efficacy. If M-PDT worked in AK still need to investigate. Approach A splie-face controlled clinical study was conducted. Eleven patients with facial AK received C-PDT (conventional PDT) on the left and M-PDT in the contralateral area. The left area was illuminated by a red LED light (a total light dose of 140 J/cm2) after applying the ALA cream for 3 hours; the other had illumination for a total light dose of 288 J/cm2 after applying the ALA cream for 0.5 hours. The primary endpoint was the lesion clearance rate at 1 month. Secondary endpoints included pain scores, the incidence of adverse events, and cosmetic outcomes. Results At one month following 3 treatments, the lesion clearance rate of M-PDT was non-inferior to that of C-PDT (93.1% vs. 86.4%, respectively. The lesion clearance rate of M-PDT to reach 100% clearance earlier than C-PDT for grade I lesions and higher clearance rates for grade III lesions. Moreover, the pain score during illumination was significantly lower for M-PDT than for C-PDT (P < 0.01). Regarding photoaging, the Global Subjective Skin Aging Assessment (GS2A2) score showed that the total and atrophy scores of C-PDT and M-PDT were significantly improved, and M-PDT also reduced discoloration. There was no significant difference in adverse reactions between C-PDT and M-PDT. Conclusions M-PDT is non-inferior to C-PDT in terms of efficacy for treating AK, resulting in much lower pain scores.