The Effect of Increasing Fluence on the Treatment of Actinic Keratosis and Photodamage by Photodynamic Therapy with 5-aminolevulinic Acid and Intense Pulsed Light

Background And Objective: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) and intense pulsed light (IPL) is a relatively new combination for the treatment of actinic keratosis (AK) and photodamage. The objective of this study was to determine the effect of increasing the fluence of IPL on the outcome of patients with these skin conditions.

Methods: Patients (N = 24) were randomly assigned to five treatment treatment groups: control (IPL alone) and ALA with 20, 25, 40, and 50  J/cm(2) fluence of IPL. Each patient received a single treatment. ALA was applied twice and allowed to incubate 2  h before IPL irradiation. Results were evaluated 5-7 days and 8 weeks after treatment. Clearance of AK lesions was evaluated by counting lesions before and after treatment, and improvement in photodamage was assessed by comparing pre- and post-treatment photographs. Statistical evaluation was based at nonparametric tests with a cut-off level at p < 0.10 and a confidence interval at 95%.

Results: Responses to treatment were greatest in patients who received ALA and IPL fluences of 40 and 50  J/cm(2). Responses were "marked" in 19% of the patients receiving 50  J and "moderate" in 19% of the patients receiving 40  J. Compared to the mean pre-treatment AK grades, the mean post-treatment grades were 56% lower in the 50  J treatment group, 32% lower in the 25  J group, 50% lower in the 40  J group, 20% lower in the 20  J group, and 7% lower in the control group. Erythema, edema, crusts and erosion, and pain did not cause any patient to discontinue the study.

Conclusion: AK clearance, but not photorejuvenation, appears to improve with increasing fluence at the ALA PDT-IPL levels used in this study without serious adverse effects.