A Non-randomized, Open-label, Multicenter Study to Evaluate the Safety and Tolerability of 10% Aminolevulinic Acid Gel in the Expanded Field-directed Treatment of Actinic Keratosis on the Face and Scalp with Red Light Photodynamic Therapy.

Abstract

Objective: Dermatologists regularly encounter patients having expanded fields with numerous actinic keratosis (AK) lesions on the face and scalp. Field-directed red light photodynamic therapy (PDT) is a well-established treatment, yet published data on the safety of PDT on large areas is scarce. We aimed to evaluate the safety and tolerability of red light PDT in treating expanded AK fields on the face and scalp.

Methods: This was a non-randomized, open-label, multicenter study. After lesion preparation, 6g of 10% aminolevulinic acid (ALA) gel were applied to the treatment field (60 cm²) and incubated for three hours under a light-blocking, occlusive dressing before 10-minute illumination with a red light lamp (~635nm, 37 J/cm²). Safety and tolerability were assessed throughout the study.

Results: All participants (n=100) had adverse reactions. No previously unknown effects, serious adverse events, or deaths were reported. The most frequent application site reactions were pain/burning (96.0%), exfoliation (87.0%), and erythema (86.0%). Most treatment-emergent adverse events were of mild to moderate severity and lasted slightly longer compared to those experienced after treatment of smaller areas. The mean maximum pain during PDT was 7.4±2.1 on an 11-point numeric rating scale. A transient increase in blood pressure on the day that PDT was performed was not clinically significant.

Limitations: Although the allowed use of pain-reducing measures might have influenced evaluation of pain, it reflects how the procedure is managed in current practice.

Concklusion: PDT with 10% ALA gel and red light illumination on an expanded treatment field was generally well tolerated.