Salvage Perioperative Interstitial High-Dose-Rate Interventional Radiotherapy (Brachytherapy) for Local Recurrences of the Chest Wall Following Mastectomy and Previous External Irradiation.

(1) Background: To investigate the technical feasibility, safety, and efficacy of interstitial perioperative high-dose-rate interventional radiotherapy (HDR-IRT, brachytherapy) as a local salvage treatment combined with surgery for local chest wall recurrences following mastectomy and subsequent external beam radiation treatment (EBRT). (2) Methods: A retrospective analysis of 56 patients treated with interstitial HDR-IRT in combination with local surgery of a chest wall recurrence of breast cancer after previous treatment with mastectomy and EBRT from 2008 to 2020. (3) Results: Local recurrence following HDR-IRT was encountered in seven (12.5%) patients. The 1-year local recurrence-free survival (RFS), 3-year RFS, and 5-year RFS were 91%, 82%, and 82%, respectively. The 1-year overall survival (OS), 3-year OS, and 5-year OS was 85.5%, 58%, and 30%, respectively. Acute grade 1-2 radiation dermatitis was observed in 22 (39.3%) patients. Late ≥grade 3 toxicities were encountered in five (8.9%) patients. (4) Conclusions: Salvage perioperative interstitial high-dose-rate interventional radiotherapy (brachytherapy) combined with surgery seems to be an effective interdisciplinary management with acceptable treatment-related toxicity for local recurrences of the chest wall following mastectomy and previous external irradiation.