Second breast conserving surgery and interstitial radiotherapy for the treatment of breast tumor local recurrences

Introduction and aim: To report the clinical outcomes of second breast-conserving therapy with perioperative interstitial radiotherapy for the treatment of ipsilateral breast tumor recurrences. Method: Between 1999 and 2015, 33 patients, presenting with an ipsilateral breast tumor recurrence after previous breast conserving therapy, were salvaged by re-excision and perioperative high-dose-rate interstitial brachytherapy. A median of 8 (range: 4-24) catheters were implanted into the tumor bed intraoperatively. A total dose of 22 Gy in 5 fractions of 4.4 Gy was delivered to the tumor bed with a margin of 1-2 cm, on 3 consecutive days. The adjuvant systemic treatments consisted of hormonal therapy for 24 patients (73%) and chemotherapy for 6 patients (18%). The survival results were estimated by the Kaplan-Meier method. Late side effects and cosmetic results were also registered. Results: The median follow-up time following the second breast conserving therapy was 61 months (range: 26-189 months). During the follow-up, 4 patients (12.1%) developed second local recurrence. The five-year actuarial rates of the second local, regional and distant recurrence were 6.3%, 6.1%, and 14.9%, respectively. The five-year probabilities of disease-free, cancer-specific and overall survival were 76.2%, 92.4%, and 89.2%, respectively. Four (12%), 19 (58%), 4 (12%) and 6 (18%) patients had excellent, good, fair and poor cosmetic results, respectively. Grade 2 and 3 fibrosis developed in 9 (27%) and 1 (3%) patients. Asymptomatic fat necrosis was detected in 7 (21%) women. Conclusion: Second breast conserving therapy with perioperative high-dose-rate interstitial brachytherapy is a safe and feasible option for the management of ipsilateral breast tumor recurrences. Interstitial brachytherapy may decrease the risk of second local relapse with acceptable cosmetic results and low rate of late side effects. Hence, in selected cases it can provide a feasible alternative to salvage mastectomy.