Photodynamic therapy with ablative carbon dioxide fractional laser for treating Bowen disease.

Background: Topical photodynamic therapy (PDT) has been increasingly used to treat malignant skin tumors including the Bowen disease. However, patients could be displeased with the long incubation time required for conventional PDT.

Objective: We evaluated the efficacy and safety of PDT with a short incubation time of ablative CO2 fractional laser pretreatment for treating Bowen disease.

Methods: Ten patients were included. Just before applying the topical photosensitizer, all lesions were treated with ablative CO2 fractional laser, following the application of methyl aminolevulinate and irradiation with red light (Aktilite CL 128). Histological confirmation, rebiopsy, and clinical assessments were performed. Adverse events were also recorded.

Results: Five of the ten (50%) lesions showed a complete response (CR) within three PDT sessions. After four treatment sessions, all lesions except one penile shaft lesion (90%) achieved clinical and histological CR or clinical CR only. The average number of treatments to CR was 3.70±1.70. The treatments showed favorable cosmetic outcomes and no serious adverse events.

Conclusion: The results suggest that pretreatment with an ablative fractional CO2 laser before PDT has similar treatment efficacy and requires a shorter photosensitizer incubation time compared with the conventional PDT method.