[INTRAOPERATIVE RADIOTHERAPY FOR EARLY BREAST CANCER - THE SHEBA EXPERIENCE AND EARLY OUTCOMES].

AIMS: This study presents our experience with Intra-Operative Electron Radio-Therapy (IOeRT) using a mobile linear accelerator at the Sheba Medical Center. BACKGROUND: Intraoperative radiotherapy is an alternative approach of partial breast irradiation for patients with early breast cancer and low risk for local recurrence who are undergoing breast conservation surgery. METHODS: Patients were selected by a multidisciplinary team according to ASTRO\GEC-ESTRO guidelines for partial breast irradiation. IOeRT was administered using SIT LIAC HWL®. RESULTS: A total of 28 patients were referred for breast conservation surgery and IOeRT between 8/2019 and 10/2020; 27/28 received IOeRT. In one patient, radiation was aborted due to anaphylactic shock in response to patent blue dye injected for sentinel node identification. Larger than usual seroma were reported on the first post-operative visit in all patients, and regressed spontaneously in 3-6 months. Infected seroma developed post-operatively in 5 patients, requiring surgical drainage in 2 patients. Final pathology matched the preoperative biopsy. There were no cases of pathology upstaging requiring additional adjuvant irradiation or chemotherapy. The patient who did not receive IOeRT was treated with adjuvant external radiotherapy. CONCLUSIONS: IOeRT is a safe alternative to partial breast irradiation, with a slight increase of postoperative infection rate.