Five-year results of a prospective case series of accelerated hypofractionated whole breast radiation with concomitant boost to the surgical bed after conserving surgery for early breast cancer.

Accelerated hypofractionation (HF) using larger dose per fraction, delivered in fewer fractions over a shorter overall treatment time, is presently a consistent possibility for adjuvant whole breast radiation (WBRT) after breast-conserving surgery for early breast cancer (EBC). Between 2005 and 2008, we submitted 375 consecutive patients to accelerated hypofractionated WBRT after breast-conserving surgery for EBC. The basic course of radiation consisted of 45 Gy in 20 fractions over 4 weeks to the whole breast (2.25 Gy daily) with an additional daily concomitant boost of 0.25 Gy up to 50 Gy to the surgical bed. Overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS) and local control (LC) were assessed. Late toxicity was scored according to the CTCAE v3.0; acute toxicity using the RTOG/EORTC toxicity scale. Cosmesis was assessed comparing treated and untreated breast. Quality of life (QoL) was determined using EORTC QLQ-C30/QLQ-BR23 questionnaires. With a median follow-up of 60 months (range 42-88), 5 years OS, CSS, DFS and LC were 97.6, 99.4, 96.6 and 100 %, respectively. Late skin and subcutaneous toxicity was generally mild, with few events > grade 2 observed. Cosmetic results were excellent in 75.7 % of patients, good in 20 % and fair in 4.3 %. QoL, assessed both through QLQ-C30/QLQ-BR23, was generally favorable, within the functioning and symptoms domains. Our study is another proof of principle that HF WBRT with a concurrent boost dose to the surgical cavity represents a safe and effective postoperative treatment modality with excellent local control and survival, consistent cosmetic results and mild toxicity.