ESTRO 2025 - Abstract Book

S475

Clinical - Breast

ESTRO 2025

Meditec, Germany). Additional postoperative WBRT (46–50 Gy) was applied if risk factors were present. [1] IORT could not be applied due to geometric/technical/anatomic/logistic reasons in 6% of the patients. Systemic therapy was applied according to international standards and guidelines. The primary outcome was the local recurrence free rate (RFR). Late toxicities over time were assessed by LENT SOMA criteria. Cosmetic outcomes were assessed by BCCT.core. Results: Of 591 included patients, 383 patients received IORT only, 132 patients received IORT + WBRT and 36 patients received WBRT only. RFR was high throughout the study period, with 99.8%, 99.4%, 97.6% and 97.1% of patients free of recurrence after 1, 3, 5 and 7 years post treatment. We observed either no or mostly mild late toxicities after 7 years for most patients, the most frequent were fibrosis (grade II–III: 15.7%), pain (grade II–III: 3.3%), retractions (grade I: 30%) and teleangiectasia (grade I: 8.9%). Cosmetic outcomes were excellent or good for most patients within TARGIT-E. Conclusion: The recurrence rate was considerably lower than reported in trials omitting radiotherapy completely in similar patient cohorts. [2, 3] Considering a high local recurrence-free rate and low occurrence of late toxicities over 7 years, TARGIT-E has shown that targeted IORT is a feasible and excellent method for RT after BCS also for elderly patients. References: 1. Neumaier C, Elena S, Grit W, et al. TARGIT-E(lderly)—Prospective phase II study of intraoperative radiotherapy (IORT) in elderly patients with small breast cancer. BMC Cancer. 2012;12(1). 2. Kunkler IH, Williams LJ, Jack WJL, Cameron DA, Dixon JM. Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer (PRIME II): a randomised controlled trial. The Lancet Oncology. 2015;16(3):266-73. 3. Kunkler IH, Williams LJ, Jack WJL, Cameron DA, Dixon JM. Breast-Conserving Surgery with or without Irradiation in Early Breast Cancer. N Engl J Med. 2023;388(7):585-94. Digital Poster SIRAЯI Ƨ : Survey of Internal mammary Radiotherapy Among Radiation-oncologists from Italy & Spain Angel Montero Luis 1,2 , Meritxell Arenas 3,4 , Cynthia Aristei 5,6 1 Radiation Oncology, HM Hospitales, Madrid, Spain. 2 Faculty of Health, Universidad Camilo José Cela, Madrid, Spain. 3 Radiation Oncology, Hospital Sant Joan de Reus, Reus (Tarragona), Spain. 4 Faculty of Medicine, Universitat Rovira i Virgili, Tarragona, Spain. 5 Radiation Oncology Section, Perugia General Hospital, Perugia, Italy. 6 Department of Medicine and Surgery, University of Perugia, Perugia, Italy Background: clinical guidelines recommendations for internal mammary chain (IMC) irradiation are not uniformly accepted and seems to exist notable differences between different countries and healthcare systems. We present the results of a survey on internal mammary chain irradiation among radiation oncologists specializing in breast cancer radiotherapy in Italy and Spain. Material and methods: an online survey was designed using Google Forms platform and distributed to breast cancer dedicated radiation oncologists. The questionnaire comprised a total of 26 questions, 9 related to epidemiological data of the participants and 17 clinical questions focused on IMC irradiation. Survey participation was voluntary with no financial incentives for responders. Keywords: intraoperative radiotherapy (IORT), APBI, elderly 1229