Results of chest wall reirradiation using pulsed-dose-rate (PDR) brachytherapy molds for breast cancer local recurrences

Purpose: We report in a retrospective study on the effect and toxicity of chest wall reirradiation using pulsed-dose-rate (PDR) afterloading molds. Methods and Materials: Between 1993 and 1999, a total of 58 patients were treated. AII patients presented with locally recurrent breast cancer (31 patients had concomitant distant metastases) after mastectomy and a previously completed course of radiation therapy (median, 54 Gy; range, 36-70). Indication for reirradiation was a progressive macroscopic skin recurrence in 30 cases and an incomplete surgical resection in 28 patients. Standard treatment consisted of a split course with two fractions of 20 Gy (interval, 31 days). The reference dose was prescribed to the skin surface at 5 mm distance from the source. PDR brachytherapy (37 GBq Ir-192) was carried out after geometric distance optimization with 0.5-1 Gy/pulse/h. The irradiated median area was 423 cm(2) (range, 100-919). The median follow-up was 18 months (range, 7-84). Results: The actuarial 1-, 2- and 3-year local recurrence-free survival rates in patients treated for macroscopic disease (microscopic disease in parenthesis) were 89% (96%), 81% (85%), and 75% (71%), Local control was obtained in 24/30 (22/28) patients. Twenty-nine of the 34 patients (85%) who deceased during follow-up were locally controlled. 9/58 patients experienced Grade III acute toxicity, 35/58 patients Grade III (29/58 telangiectasia, 6/58 contracture), and 4/58 Grade IV late toxicity (RTOG/EORTC). Conclusion: Reirradiation of the chest wall using PDR brachytherapy molds is effective and provides a high local control rate with acceptable toxicity. (C) 2001 Elsevier Science Inc.