A controlled trial of photodynamic therapy of actinic keratosis comparing different red light sources

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) with red light is well established for actinic keratosis (AK). Differences have been observed concerning pain and efficacy rates with different red light sources.

To compare pain scores, short- and long-term efficacy rates of PDT of multiple AKs when employing different red light sources.

In a controlled trial, 88 patients (310 AK lesions) received ALA-PDT in combination with either visible light (VIS) + water-filtered infrared A (wIRA) light (PhotoDyn(®) 750 (PD750), 580-1400 nm) for 30 min or incoherent light (Waldmann(®) 1200L (Wa1200L), 600-720 nm) for 10-11 min. Follow-up visits were performed after 1, 3, 6, and 12 months. If there was no complete cure after 1, 3 or 6 months, a second cycle of PDT was performed.

Pain scores were significantly lower in patients illuminated with PD750 rather than Wa1200L. Patient complete clearance rates were 85% and 91% after 1 month, 79% and 92% after 3 months, 97% and 92% after 6 months, and 69% and 85% after 12 months in the PD750 and Wa1200L groups, respectively. Lesion complete clearance rates were 94% and 92% after 1 month, 88% and 97% after 3 months, 96% and 95% after 6 months, and 81% and 89% after 12 months in the PD750 and Wa1200L group, respectively. The efficacy rates were not significantly different.

A VIS + wIRA light source produced considerably less pain, while efficacy was not much affected in contrast to previously published studies, probably because the illumination time was longer in this study.