Essential requirements for reporting radiation therapy in breast cancer clinical trials: An international multi-disciplinary consensus endorsed by the European Society for Radiotherapy and Oncology (ESTRO).

The European Society for Radiotherapy and Oncology (ESTRO) has advocated the establishment of guidelines to optimise precision radiotherapy (RT) in conjunction with contemporary therapeutics for cancer care. Quality assurance in RT (QART) plays a pivotal role in influencing treatment outcomes. Clinical trials incorporating QART protocols have demonstrated improved survival rates with minimal associated toxicity. Nonetheless, in routine clinical practice, there can be variability in the indications for RT, dosage, fractionation, and treatment planning, leading to uncertainty. In pivotal trials reporting outcomes of systemic therapy for breast cancer, there is limited information available regarding RT, and the potential interaction between modern systemic therapy and RT remains largely uncharted. This article is grounded in a consensus recommendation endorsed by ESTRO, formulated by international breast cancer experts. The consensus was reached through a modified Delphi process and was presented at an international meeting convened in Florence, Italy, in June 2023. These recommendations are regarded as both optimal and essential standards, with the latter aiming to define the minimum requirements. A template for a case report form (CRF) has been devised, which can be utilised by all clinical breast cancer trials involving RT. Optimal requirements include adherence to predefined RT planning protocols and centralised QART. Essential requirements aim to reduce variations and deviations from the guidelines in RT, even when RT is not the primary focus of the trial. These recommendations underscore the significance of implementing these practices in both clinical trials and daily clinical routines to generate high-quality data.

Competing Interests: Declaration of competing interest IMe declares advisory boards supported by Eli Lilly, Novartis, Pfizer, Pierre Fabre, SeaGen, Daiichi Sankyo, Astra Zeneca. CB declares honoraria supported by declares advisory boards supported by Eli Lilly, Novartis, Pfizer, and Amgen. ML received honoraria and/or participated in advisory board from Roche, Novartis, Lilly, Pfizer, AstraZeneca, Daiichi Sankyo, Gilead, SeaGen, MSD, Exact Sciences, Takeda, Ipsen, Sandoz, Libbs & Knight, a travel grant from Gilead and research support to the Institution from Gilead. EdA disclosed honoraria and/or advisory board from Roche/GNE, Novartis, SeaGen, Zodiac, Libbs, Pierre Fabre, Lilly, AstraZeneca. JC disclosed consulting/advisor for Roche, Celgene, Cellestia, AstraZeneca, SeaGen, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Merck Sharp & Dohme, GSK, Leuko, Bioasis, Clovis Oncology, Boehringer Ingelheim, Ellipses, Hibercell, BioInvent, Gemoab, Gilead, Menarini, Zymeworks, Reveal Genomics, Expres2ion Biotechnologies. NH disclosed honoraria for lectures and/or consulting from AstraZeneca, Daiichi-Sankyo, Gilead, Lilly, MSD, Novartis, Pierre-Fabre, Pfizer, Roche, Sanofi, Sandoz, SeaGen. HSR disclosed institutional research support by Astellas Pharma Inc., AstraZeneca, Daiichi Sankyo Inc., F. Hoffmann-La Roche AG/Genentech, Inc., Gilead Sciences Inc., GlaxoSmithKline, Lilly, Merck & Co. Inc., Novartis Pharmaceuticals Corporation, OBI Pharma, Pfizer, Pionyr Immunotherapeutics, Sermonix Pharmaceuticals Inc., Taiho Oncology Inc., and Veru Inc. GC reports personal fees for consulting, advisory role and speakers’ bureau from Roche/Genentech, Novartis, Pfizer, Lilly, Foundation Medicine, Samsung and Daiichi Sankyo; honoraria from Ellipses Pharma and fees for travel and accommodations from Roche/Genentech and Pfizer. LV declares participation on advisory board from Daiichi Sankyo and Pfizer. ME declares advisory board supported by Pfizer and Novartis and lecture fees supported by AstraZeneca. GM declares consultancy honoraria from Roche, Novartis, AstraZeneca, Pfizer, Jensen, Lilly, and Sanofi. LDM declares consulting fees from Roche, Novartis, Eli Lilly, MSD, Daiichi Sankyo, SeaGen, Gilead, Eisai, Pierre Fabre, AstraZeneca, Stemline Menarini, Exact Sciences, Agendia, GSK, Pfizer. No other competing interests declared.

(Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)