Second breast-conserving therapy with interstitial brachytherapy (APBI) as a salvage treatment in ipsilateral breast tumor recurrence: a retrospective study of 40 patients.

ABSTRACT

PURPOSE: Breast-conserving treatment (BCT) have emerged as an alternative to mastectomy in patients with ipsilateral breast tumor recurrence (IBTR). We evaluated survival outcomes and treatment-related toxicity in a series of 40 patients with IBTR, who underwent tumorectomy plus interstitial brachytherapy (APBI) as a salvage treatment. MATERIAL AND METHODS: Retrospective analysis included 40 patients diagnosed with IBTR and treated with intraoperative (26 patients) or post-operative (14 patients) multicatheter brachytherapy for APBI at our institution between June 2002 and October 2017. We assessed cosmesis, toxicity, overall survival (OS), and cancer-specific survival (CSS). RESULTS: Tumorectomy was performed in all cases, including intraoperative tumor margin assessment and sentinel node biopsy. Median age was 65 years (range, 41-92). The total prescribed dose was 32 Gy (8 fractions) in 19 patients and 34 Gy (10 fractions) in 20 patients. One elderly patient (age 92) received a single fraction of 16 Gy. Median follow-up was 61.5 months (range, 6-153). A median of 14 tubes were inserted. Mean treated V100 was 115 cc. Two patients developed a second relapse at 3 and 5 years after salvage treatment one patient underwent salvage mastectomy and remains alive 10 years after brachytherapy, and the second one developed both local relapse and bone metastasis. The disease is stable at present. Five-year OS and CSS rates were 85.3% and 97.5%, respectively. Two patients died from cancer-related causes. Acute and late toxicity rates were low; seven patients developed acute infectious mastitis. Late fibrosis > grade 3 and late mastitis were observed in 14 and 6 cases, respectively. CONCLUSIONS: Second BCT with APBI as a salvage treatment in ipsilateral breast recurrence achieves good local disease control, with a satisfactory toxicity profile compared to mastectomy. This approach seems to be safe and effective, although more data from randomized trials are needed.