LAUSR

Introduction Hypofractionated whole breast irradiation (HWBI) is the current standard of treatment after breast conservative surgery (BCS). Intraoperative radiotherapy (IORT) must be associated to WBI in patients showing high-risk factors of local recurrence in the definitive pathology report. The aim of this trial was to evaluate, for the first time, the acute toxicity and cosmesis of HWBI after photon-IORT. Materials and methods Twenty-six luminal breast cancer patients treated by BCS and IORT(20 Gy) were included between February and December 2019, in this prospective trial, of adjuvant HWBI (40.5 Gy/2.67 Gy/15 fractions). Acute toxicity (CTCAEv5.0) and cosmesis (Harvard scale), were assessed 3 months after treatment. Results All patients completed their treatment without interruptions. All cases were evaluable 3 months after treatment showing no toxicity ≥ G3 and excellent/good cosmesis assessment in 88% of the patients. Conclusion HWBI seems to have similar acute toxicity and cosmesis results than conventionally fractionated WBI in combination to photon-IORT after BCS.