ESTRO 2025 - Abstract Book

S1548

Clinical – Mixed sites & palliation

ESTRO 2025

3127

Digital Poster International consensus on palliative radiotherapy endpoints for future clinical trials in bone metastases: a second update Eva Oldenburger 1 , Jane Jomy 2 , Inmaculada Navarro-Domenech 3 , Joanne M. Van der Velden 4 , Shing Fung Lee 5,6 , Henry C. Y. Wong 7 , Mateusz Spalek 8 , Gustavo N. Marta 9 , Peter Hoskin 10,11 , Yvette M. Van der Linden 12 , Johan Menten 1 , Charles B. Simone II 13,14 , Dirk Rades 15 , Edward Chow 16 , Philip Wong 2 , Srinivas Raman 17 1 Department of Radiation Oncology, University Hospitals Leuven, Leuven, Belgium. 2 Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Canada. 3 Department of Radiation Oncology, Hospital Universitario La Paz, Madrid, Spain. 4 Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, Netherlands. 5 Department of Radiation Oncology, National University Cancer Institute, Singapore, Singapore. 6 Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong, China. 7 Department of Oncology, Princess Margaret Hospital, Hong Kong, China. 8 Institute of Oncology, The Maria Sklodowska-Curie National Research Institute of Warsaw, Warsaw, Poland. 9 Department of Radiation Oncology, Hospital Sírio-Libanês, São Paulo, Brazil. 10 Mount Vernon Cancer Centre, Mount Vernon Cancer Centre, Northwood, United Kingdom. 11 Division of Cancer Sciences, University of Manchester, Manchester, United Kingdom. 12 Department of Radiotherapy, Leiden University Medical Centre, Leiden, Netherlands. 13 New York Proton Center, New York Proton Center, New York, USA. 14 Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA. 15 Department of Radiotherapy, University Medical Center Schleswig-Holstein/Lübeck, Lübeck, Germany. 16 Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Canada. 17 Department of Radiation Oncology, BC Cancer, Vancouver, Canada Purpose/Objective: External beam radiotherapy (EBRT) is a well-established treatment for palliating symptoms associated with bone metastases. Numerous randomized trials have consistently demonstrated the efficacy of EBRT in symptom management. However, the use of diverse endpoints across studies has resulted in heterogeneous outcomes, complicating cross-trial comparison. To address this, the International Bone Metastases Consensus Working Party published a consensus guideline in 2002 to standardize trial endpoints for palliative EBRT in bone metastases, with an update in 2012, reflecting advancements in clinical practice and technological developments. This study aims to review, evaluate and update the last consensus, to promote consistency in future clinical trial design for bone metastases. Material/Methods: Applying the Delphi Method, an electronic survey was developed based on a comprehensive literature review and relevant guidelines published since 2012, to identify necessary revisions, additions and updates to the consensus. Participants, including previous contributors and other experts with a recognized interest in radiotherapy for bone metastases, were identified globally and invited to participate. These experts represent the American Society for Radiation Oncology (ASTRO), the European Society for Therapeutic Radiology and Oncology (ESTRO), the Faculty of Radiation Oncology of the Royal Australian and New Zealand College of Radiologists (RANZCR), and the Canadian Association of Radiation Oncology (CARO). Statements failing to achieve consensus (defined as greater than 75% agreement) in the Phase I survey, were reviewed and refined by the Working Party. These refined statements discussed by eight Working Party experts and statements were circulated to the entire Working Party for additional feedback before inclusion in the Phase II survey. Descriptive statistics were used to summarize the results, with statements categorized based on the level of agreement. Results: Of 136 experts contacted, 58 participated in the Phase I, establishing consensus on 28 of 36 statements (78%). Consensus was achieved across several key areas, including eligibility criteria for future trials, pain and analgesic assessments, radiation techniques and dose specifications, follow-up protocols, timing and type of assessments, and cost-effectiveness considerations. Of these, eight statements are new additions (Figure 1). The results of the Phase II survey will be available for the 2025 ESTRO Annual Congress.