Work

Pigmented pathological type and depth of follicular extension as predictors of treatment failure in 5-aminolevulinic acid photodynamic therapy for actinic keratosis: A retrospective, matched nested case-control study

Year: 2025

Type: article

Abstract: Background 5-Aminolevulinic acid photodynamic therapy (ALA-PDT) is commonly used for actinic keratosis (AK), but resistance and recurrence remain problematic. Methods This study analyzed 119 patients with histologically confirmed AK treated with four ALA-PDT sessions to identify predictors of treatment effectiveness. Initial complete clearance (ICC) at 3 months and sustained complete clearance (SCC) at 12 months were assessed. Results ICC was achieved in 89% (106/119) of patients, with 79% (65/82) maintaining SCC. Pigmented AK predicted treatment resistance (OR=44.05, p=0.00). Follicular extension to the isthmus or deeper predicted recurrence (OR=17.26, p=0.00). Conclusion Pigmented AK and deep follicular extension are independent predictors of ALA-PDT resistance and recurrence in AK, respectively.

Source: Photodiagnosis and Photodynamic Therapy

DOI: 10.1016/j.pdpdt.2025.104801