Interstitial high-dose-rate brachytherapy after breast conserving surgery

We evaluated local recurrence, toxicity rate and cosmetic outcome in 72 patients treated with high-dose-rate (HDR) brachytherapy after breast conserving surgery. HDR brachytherapy was administered: i) as partial breast irradiation (PBI) in 64 patients with low-risk early stage breast cancer, enrolled in a phase II prospective study; ii) as PBI after a second conservative surgery as treatment of local relapse in 3 patients; iii) for delivering a boost after whole breast external beam radiotherapy in 5 patients. Implantation was done during surgery (breast conserving or re-excision to achieve adequate surgical margins), with the wound open, or postoperatively. The implant was well tolerated in all patients, so no premature catheter removal was required. At a median follow-up of 32 months (range 5-52) no local recurrence has been observed. Toxicity was very low. Cosmetic outcome was excellent/good in a high percentage of patients. Our results suggest that PBI administered with HDR brachytherapy is feasible in selected patients with low risk early stage breast carcinoma. PBI seems feasible to repeat radiotherapy after a salvage breast conserving surgery for local relapse in a second attempt to preserve the breast.