Photodynamic therapy in the management of basal cell carcinoma: Retrospective evaluation of outcome

Introduction: Photodynamic therapy (PDT) is a relatively new method of treating various kinds of pathologies. In this retrospective study, a total of 148 patients with basal cell carcinoma (BCC) were treated with surface illumination methyl aminolevulinate - photodynamic therapy (MAL-PDT) or meta-tetrahydroxyphenylchlorin (mTHPC-PDT). Comparisons with the clinical features, rate of recurrence and overall outcome were made. Materials and methods: Surface illumination PDT was offered under local or general anaesthesia. For thin BCCs, the 16% strength cream (MAL) was applied topically 3 h prior to tissue illumination. A single-channel 628 nm diode laser was used for illumination and light was delivered at 100J/cm(2) per site. For thick BCCs, 0.05 mg/kg mTHPC was administered intravenously prior to tissue illumination. A single-channel 652 nm diode laser was used for illumination and light was delivered at 20J/cm(2) per site. Lesion response evaluation was carried out according to RECIST. Results: The MAL-PDT sub-group included 86 patients with 127 thin BCCs; 80 patients had complete response (CR) after one round of treatment. The mTHPC-PDT sub-group included 62 patients with 116 thick BCCs; 60 patients had complete response after one round of treatment. Statistically significant factors associated with complete response to MAL-PDT included superficial BCC histotype (P < 0.001), <= 0.5 mm tumour thickness (P < 0.001) and lack of ulceration (P < 0.001). While for the mTHPC-PDT sub-group, both superficial and nodular types responded significantly better than invasive type (P < 0.001); the lack of ulceration was insignificant factor in achieving complete response. Conclusion: PDT achieved high efficacy in the treatment of basal cell carcinomas with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients.