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 1 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 posttreatment cosmesis, high efficacy rates with respect to head lesions, and practical applicability to large body surface areas.