Laser-mediated photodynamic therapy of actinic keratoses

Objective: To assess the safety and efficacy of the long-pulsed pulsed dye laser (LP PDL) (595 nm) with photodynamic therapy (PDT) for treatment of actinic keratoses (AKs). Design: Prospective, controlled study with 10-day and 2-, 4-,6-, and 8-month follow-ups. Setting: Clinical research center. Patients: Volunteer sample of 41 patients (age range, 35-91 years; skin types I-III) with AKs. Intervention: Single treatment with application of topical 20% 5-aminolevulinic acid for 3 hours or 14 to 18 hours, followed by LP PDL irradiation at 595 nm. Controls received LP PDL irradiation alone. Main Outcome Measures: Safety assessments, treatment and recovery times, and efficacy assessments, including patient mean percentage of lesions cleared and distribution of patients by percentage of lesions cleared for different anatomic sites. Results: We observed no to slight pain; slight to moderate erythema; no purpura, crusting, or scarring;, treatment time of I lesion per second; and resolution of erythema by 7 to 14 days. The patient mean (95% confidence interval) percentage of head lesions (2620 lesions) cleared after 1 treatment was 99.47% (99.44%-99.50%) at 10 days, 98.19% (98.15%-98.23%) at 2 months, 92.94% (92.73%-93.14%) at 4 months, 91.65% (91.15%-92.15%) at 6 months, and 90.32% (78.10%-100%) at 8 months. For extremities (949 lesions), these were 83.1% (81.4%-84.9%) at 10 days, 75.5% (73.4-77.6) at 2 months, 70.9% (68.9%-72.8%) at 4 months, 92.0% (84.0%-100%) at 6 months, and 100% at 8 months. For trunk (53 lesions), these were 85% (74%-100%) at 10 days, 85% (74%-100%), and 65% (50%-80%) at 4 months. No difference in safety or efficacy was found between the 3-hour and 14- to 18-hour incubation times. In the laser-only control group, no decrease in lesions was observed. Among 31 patients with head lesions, 28 (90%) at 10 days, 19 (70%) at 2 months, 9 (47%) at 4 months, 5 (42%) at 6 months, and 5 (56%) at 8 months were completely (100%) clear following a single treatment. Skin biopsy specimens of nonresponding lesions demonstrated a high rate of squamous cell carcinoma and other non-AK neoplasms. Conclusions: Treatment of AKs using LP PDL (595 nm) at nonpurpuric parameters following topical application of 5-aminolevulinic acid is safe and effective. The advantages may include minimal discomfort, rapid incubation treatment and recovery times, excellent post-treatment cosmesis, high efficacy rates with respect to head lesions, and practical applicability to large body surface areas.