Accelerated partial breast irradiation in a single 18 Gy fraction with high-dose-rate brachytherapy: preliminary results

Purpose: To evaluate the feasibility of acute and chronic toxicity in patients suitable for accelerated partial breast irradiation (APBI) in a single 18 Gy fraction with multicatheter high-dose-rate (HDR) brachytherapy, as well as cosmetic and oncological outcomes. Material and methods: Between September 2014 and March 2016, twenty consecutive patients with low-risk invasive and ductal carcinoma in situ were treated with interstitial multicatheter HDR brachytherapy in a single 18 Gy fraction. Results: Median age was 63.5 years (range, 51-79). Acute toxicity was observed in seven patients, while the pain during following days and hematoma were seen in four patients. With a median follow-up of 24 months, late toxicity was found in one patient with fat necrosis g2 and fibrosis g2 in another patient. The overall survival (OS) and locoregional control (LC) was 100%. Disease-free survival (DFS) and distant control was 95%. Good to excellent cosmetic outcomes were noted in 80% of patients and fair in 4 patients (20%). Conclusions: This is the first report in the medical literature that focuses on feasibility and acute and chronic toxicity, with a median follow-up of 24 months (range, 20-40). The protocol is viable and convenient. However, a longer follow-up is needed to know chronic toxicity and oncologic outcomes.