ESTRO 2024 - Abstract Book

S520

Clinical - Breast

ESTRO 2024

1. Lee TS, Kilbreath SL, Refshauge KM et al. Prognosis of the upper limb following surgery and radiation for breast cancer. Breast Cancer Res Treat. 2008 Jul;110(1):19-37. doi: 10.1007/s10549-007-9710-9

2. Bruce J, Mazuquin B, Canaway A et al. Exercise versus usual care after non-reconstructive breast cancer surgery (UK PROSPER): multicentre randomised controlled trial and economic evaluation BMJ 2021; 375 :e066542 doi:10.1136/bmj-2021-066542

848

Mini-Oral

Treatment laterality and incidental dose to internal mammary nodes and axilla in breast radiotherapy

Fiona Wilson 1,2 , Tanwiwat Jaikuna 1 , Carmel Anandadas 2 , David Azria 3 , Sara Gutierrez-Enriquez 4 , Dirk De Ruysscher 5 , Maarten Lambrecht 6 , Tiziana Rancati 7 , Tim Rattay 8 , Christopher Talbot 8 , Elena Sperk 9 , Ana Vega 10 , Liv Veldeman 11 , Catharine West 1 , Adam Webb 8 , Jenny Chang-Claude 12 , Petra Seibold 12 , Eliana Vasquez-Osorio 1 , Marianne Aznar 1 , Victoria Reyes 13 1 University of Manchester, Radiotherapy Related Research, Manchester, United Kingdom. 2 Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom. 3 Montepellier University, Radiation Oncology, Montpellier, France. 4 Vall d'Hebron Barcelona Hospital Campus, Hereditary Cancer Geneticss Group, Barcelona, Spain. 5 Maastricht University Medical Center, Radiation Oncology, Maastricht, Netherlands. 6 Leuvens Kanker Institut, Radiotherapy-oncology, Leuven, Belgium. 7 Fondazione IRCCS Instituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy. 8 University of Leicester, Leicester Cancer Research Centre, Leicester, United Kingdom. 9 University of Heidelberg, Radiation Oncology, Mannheim, Germany. 10 Universitario de Santiago, Fundacion Publica Galega Medicina Xenomica, Santiago de Compostela, Spain. 11 Ghent University Hospital, Radiation Oncology, Ghent, Belgium. 12 German Cancer Research Center (DKFZ), Cancer Epidemiology, Heidelburg, Germany. 13 Vall d'Hebron Hospital Universitari, Radiation Oncology, Barcelona, Spain

Purpose/Objective:

Incidental, non-prescribed dose in breast radiotherapy can vary considerably with positioning, body habitus and field placement. This incidental dose may have implications for toxicity and recurrence. The dose to the axillary lateral thoracic junction (ALTJ), in the superior-lateral axilla, has been identified as a potential organ at risk for lymphoedema (1,2). Here, we aimed to evaluate the incidental dose to the internal mammary nodes (IMN), level 1 axilla (L1) and ALTJ in a prospective multi-centre cohort of patients treated with breast-conserving surgery.

Material/Methods:

The REQUITE study prospectively recruited patients between 2014-2017 in Belgium, France, Germany, Italy, Netherlands, Spain, UK and USA. Patients with available full dose distribution and supine position were selected. To assess doses in this cohort, all individual CTs and dose distributions were non-rigidly deformed to a single reference patient (NiftyReg) focusing on the breast region and 5cm superiorly and inferiorly. On this reference patient, lymph