PHOTODYNAMIC THERAPY OF ACTINIC KERATOSIS WITH TOPICAL 5-AMINOLEVULINIC ACID - A PILOT DOSE-RANGING STUDY

Objective: To examine the safety and efficacy of photodynamic therapy using topical 5-aminolevulinic acid (ALA) and red light to treat actin ic keratoses (AKs). Design: Actinic keratoses were treated with topica l ALA. (concentrations of 0%, 10%, 20%, or 30%) under occlusion for 3 hours. Before photodynamic therapy, sites were examined for fluorescen ce. Sites were irradiated with an argon pumped dye laser (630 nm) at f luences of 10 to 150 J/cm(2). Setting: Academic medical center. Patien ts: Forty patients with 6 clinically typical, previously untreated AKs per patient. Main Outcome Measurer Complete resolution and decrease. in lesion area of the AK relative to baseline evaluated at weeks 1, 4, 8, and 16. Results: Three hours after ALA administration, lesions sho wed moderate red fluorescence. Cutaneous phototoxic effects, localized erythema and edema, peaked at 72 hours. Patients experienced mild bur ning and stinging during light exposure. Eight weeks after a single tr eatment using 30% ALA, there was total clearing of 91% of lesions on t he face and scalp and 45% of lesions on the trunk and extremities. No significant differences were observed in clinical responses with treat ment using 10%, 20%, or 30% ALA. All concentrations of ALA were more e ffective than treating AKs with vehicle and light. Conclusions: Topica l photodynamic therapy with ALA is an effective treatment of typical A Ks. Complete clearing of nonhypertrophic AKs can be achieved with 10%, 20%, or 30%:ALA that is easily tolerated by the patient. Lesions on t he face and scalp are more effectively treated than lesions on the tru nk and extremities. Hypertrophic AKs did not respond effectively.