Long-term Efficacy of Ablative Fractional Laser-assisted Photodynamic Therapy for Treatment of Lower Extremity Bowen's Disease

Inclusion Criteria: * •Patients aged 18 years or more who diagnosed as bowen's disease Exclusion Criteria: * pregnancy or lactation * active systemic infectious disease * other inflammatory, infectious, or neoplastic skin diseases in the treated area * allergy to MAL,other topical photosensitizers, or excipients of the cream * history of photosensitivity * use of immunosuppressive or photosensitizing drugs * participation in any other investigational study in the preceding 30 days * history or indicators of poor compliance * Histological findings of acantholysis, desmoplasia, perineural or lymphovascular invasion, and echographic features of regional lymph node metastasis were the disease-specific exclusion criteria