Photodynamic therapy with epidermal ablation using fractional carbon-dioxide laser in the treatment of Bowen's disease: A case series

Background: Bowen's disease is an intraepithelial tumor, also known as squamous cell carcinoma in situ. Among those alternative treatments, PDT usually produce better cosmetic outcomes compared with those of 5-fluorouracil and cryosurgery. Methods: Before the applications of photosensitizer, epidermis of the lesions were totally ablated by fractional CO2 laser (eCO2®, Lutronic, Korea) with the following parameters: tip size 120 μm, peak power 30 W, pulse energy 50 mJ, 200 spots/cm2. After the ablation of epidermis, methyl aminolevulinate (MAL) (Metvix®, Galderma, France) was applied with incubation time of 90 minutes followed by light exposure. 630 nm light from Aktilite CL 128® (Galderma, Switzerland) was utilized at a light dose of 37 J/cm2. The clinical improvement of the lesion was evaluated either as a complete response (CR, complete absence of lesion), a partial response (PR, 25∼99% reduction in lesion) or no response (NR, 0∼24% reduction in lesion). Results: The treatment result was excellent (87.5% of clinical CR). No scar formation after the treatment was noted in 7 patients who achieved clinical CR. Conclusions: Total ablation of epidermis before PDT can enhance the treatment efficacy of PDT without adverse events in the treatment of Bowen's disease.