Er:YAG Ablative Fractional Laser Assisted-Photodynamic Therapy Versus Photodynamic Therapy for Nodular Basal Cell Carcinoma in Asian: A Prospective, Randomized Study With 12 Months Follow-up

Basal cell carcinoma (BCC) is the most common cancer in the Caucasian population, with an incidence rising worldwide. there is an increasing trend in the incidence rates of BCC in asian and greater percentage of pigmented BCCs is found to be the most characteristic clinical feature of BCC in Asian compared to BCC in Caucasians. Topical photodynamic therapy with methyl-aminolaevulinate (MAL-PDT) has been introduced as an alternatively attractive procedure for BCC. PDT facilitates the light activation of a photosensitizer in the presence of oxygen. The oxygen generates reactive oxygen species leading to selective and highly localized destruction of abnormal cells. MAL is an efficient photosensitizer as a result of improved lesion penetration attributed to enhanced lipophilicity, decreased charge and also has a greater specificity for neoplastic cells, compared with 5-aminolevulinic acid. Because histologic features of nBCC include down-growth of epithelial buds into the dermis, palisading basal cell and separation of epidermis from the underlying dermis, it is generally treated twice within an interval of 1 week.But, MAL-PDT shows the lower efficacy for the treatment of pigmented BCC because melanin disturbs the absorption of the MAL. Also, a significantly higher proportions of BCC in the Asian population were pigmented BCC compared with pigmented BCC of Caucasian. Consequently, additional techniques are needed to enhance the penetration and accumulation of MAL in order to improve PDT efficacy and decrease treatment duration in darker-skinned patients.

Er:YAG ablative fractional laser therapy (AFL) can ablate the epidermis and dermis without significant thermal injury. This approach creates microscopic ablation zones (MAZ) in laser-applied portion of the skin. The tissue with MAZ is surrounded by thin layers of coagulated tissue. Since the Er:YAG AFL resurfaces 5-20% of the skin at one time and does not injure the entire thickness of the epidermis, healing times are minimized. Recent studies have demonstrated that Er:YAG AFL facilitates delivery and uptake of topical MAL deep into the skin, enhancing porphyrin synthesis and photodynamic activation. We have compared the efficacy, recurrence rate, cosmetic outcomes and safety of Er:YAG AFL-PDT with standard MAL-PDT in the treatment of nBCC among Korean populations.