Real-world data of 5-aminolaevulinic acid-mediated photodynamic therapy for Bowen disease: a 10-year retrospective study in patients with darker-coloured skin (2011–2021)

BACKGROUND: Photodynamic therapy (PDT) has been strongly recommended as an excellent alternative treatment for Bowen disease (BD). However, reported data on 5-aminolaevulinic acid-mediated PDT (ALA-PDT) with red-light irradiation are limited and the long-term effectiveness remains to be determined, especially in dark-skinned populations. OBJECTIVES: We aimed to review routine clinical practice in the field of BD treatment with ALA-PDT over an extended study period (2011-2021), calculate the overall clearance rate, and explore and evaluate factors that might affect the effectiveness of therapy in a real-world setting. METHODS: The medical records of patients with BD who received ALA-PDT with red-light irradiation between February 2011 and June 2021 were reviewed and summarized. Univariate and multivariate analyses of clinically relevant variables that may affect treatment outcomes were conducted to identify risk predictors. RESULTS: The overall clearance rate of 122 BD lesions was 89.3% with a median follow-up time of 36 months. The correlation between the effectiveness and fluorescence intensity of pre-PDT or PDT sessions was statistically significant after eliminating the interference of confounding factors. All recurrences occurred in the first 2 years following ALA-PDT. CONCLUSIONS: ALA-PDT is an effective treatment for BD in patients with darker-coloured skin. Well-executed operations and effective pretreatment are the determinants of effectiveness. Fluorescence intensity of pre-PDT appeared to be a significant predictor of final effectiveness. In addition, 2 years of follow-up is necessary following ALA-PDT.