Topical photodynamic therapy using intense pulsed light for treatment of actinic keratosis: clinical and histopathologic evaluation.

Background: Photodynamic therapy (PDT) is suitable for the treatment of actinic keratosis, and, recently, topical PDT using intense pulsed light as a light source has been reported. However, evaluations of its therapeutic effects have been clinically based.

Objective: The objective of this study was to confirm the histopathologic resolution of actinic keratosis treated by topical PDT using intense pulsed light as a light source.

Methods: Twelve actinic keratosis lesions in seven patients were treated with 5-aminolevulinic acid-PDT using intense pulsed light as a light source. After a single treatment, the clinical response was assessed and histopathologic examinations were performed on clinically resolved lesions.

Results: Six of 12 (50%) lesions showed clinical clearance after a single treatment, but histologic examinations showed that only 5 of the 12 (42%) lesions had been removed. No complications, such as pigmentary changes or scarring, were observed.

Conclusion: Intense pulsed light is potentially an effective light source for PDT. However, the determination of complete remission in actinic keratosis requires caution, and long-term follow-up or histologic confirmation may be required.