Treatment of skin carcinomas of the face by high-dose-rate brachytherapy and custom-made surface molds

Purpose: To analyze the results obtained in a prospective group of patients with basal or squamous cell skin carcinomas of the face treated by high-do se-rate (HDR) brachytherapy via custom-made surface molds. Methods and Materials: A total of 136 patients with basal or squamous cell carcinomas of the face were treated between March 1992 and March 1997 by su rface molds and HDR brachytherapy with iridium-192, Nineteen patients were treated with standard Brock applicators and 117 patients with custom-made p olymethyl methacrylate applicators, built over a plaster mold obtained of t he patient's face. Minimum dose administered to the tumor was 6000 to 6500 cGy in 33 to 36 fractions at 180 cGy/fraction in lesions of up to 4 cm, Les ions greater than 4 cm were boosted up to 7500-8000 cGy after a 3-week paus e. Results: With the custom-made surface molds, the dose distribution was unif orm in the surface of the skin and at 5 mm depth in the whole area of the a pplicator. Differences between the areas of maximum and minimum dose at thi s depth never reached values higher than 5% of the prescribed dose, At the edges of the custom-made molds dose gradient was sharp, with the detected d ose at 5 mm from the applicator being negligible. All the patients were com plete responders. There were 3 local recurrences, 1/73 patients treated for primary tumor and 2/63 patients treated for recurrent tumor. Actuarial loc al control at 5 years for all patients was 98%, for those patients with pri mary tumors 99%, and for recurrent patients 87%, The treatment tolerance wa s excellent in all cases. No severe, early, or late, complications were det ected. Conclusions: Radiotherapy is a highly effective treatment of skin carcinoma s of the face. Custom-made molds, to be used in conjunction with HDR brachy therapy equipment, make possible a uniform dose distribution, with a sharp dose gradient in the limits of applicators. Custom-made surface molds are e asy and safe to use, and they fit very accurately for daily treatment. Loca l control is excellent with minimal sequelae or complications. Probably the y will become the standard way of treatment of face skin carcinomas in the near future. (C) 2000 Elsevier Science Inc.