A regimen to minimize pain during blue light photodynamic therapy of actinic keratoses: Bilaterally controlled, randomized trial of simultaneous versus conventional illumination

Abstract

Bluelight photodynamic therapy (PDT) is effective for actinic keratosis, but many patients experience stinging pain during illumination. To compare a conventional regimen (1hour of 5-aminolevulinic acid [ALA] preincubation, followed by blue light) versus a new modified regimen in which blue light is started immediately after ALA application. A clinical trial with a bilaterally controlled, intrapatient study design was conducted with 23 patients. Topical 20% ALA was applied to the entire face and/or scalp. On 1 side of the body, blue light was started immediately and continued for either 30, 45, or 60minutes (simultaneous PDT). On the contralateral side, the blue light began 1hour after ALA application and lasted 1000seconds (conventional PDT). Pain was evaluated on a scale from 0 to 10. Actinic keratosis lesion counts were determined by clinical examination and photography. All patients experienced significantly less pain during simultaneous illumination than during the conventional regimen. At 3months after treatment, lesion clearance was nearly identical on the 2 sides, as determined by statistical testing of noninferiority ± 15% margin. Although bilaterally controlled, the study was relatively small. Additional studies are recommended. The modified PDT regimen is essentially painless, yet it provides treatment efficacy similar to a conventional regimen.