Intraindividual, right-left comparison of topical 5-aminolevulinic acid photodynamic therapy vs. 5% imiquimod cream for actinic keratoses on the upper extremities

Backround Actinic keratoses (AKs) are considered as in situ squamous cell carcinoma. Early and effective treatment is important. Objective To compare the efficacy, cosmetic outcome and patient preference of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) with that of 5% imiquimod (IMIQ) cream in patients with AKs on the dorsa of hands and forearms. Methods Subjects received two ALA-PDT treatment sessions and one or two courses of imiquimod (three times per week for 4 weeks each). Treatments were randomly allocated to alternate upper extremities. Assessments included lesion response one and six months after treatment, cosmetic outcome evaluated by the investigators and patients' preference 6 months after treatment. Efficacy end point included the individual AK lesion clearance rate. Results Thirty patients with 256 lesions were included in the study. At the first follow-up, treatment with ALA-PDT resulted in significantly larger rate of cured lesions relative to 5% IMIQ cream (70.16% vs. 18.26%). At the second follow-up both treatments showed a high rate of cured lesions (65.32% for PDT vs. 55.65% for IMIQ cream). Response rates obtained in grade I lesions were higher for both treatments (71.64% for PDT vs. 72.13% for IMIQ), while treatment with PDT resulted in a significant larger rate of cured grade II lesions (57.89% for PDT vs. 37.03 for IMIQ). Difference in cosmetic outcome was not statistically significant. Results for subject preference favoured ALA-PDT. Conclusions Our study shows that ALA-PDT and 5% IMIQ cream are both attractive treatment options for upper extremities AKs with comparable efficacy and cosmetic outcomes. Conflicts of interest None declared.