ESTRO 2025 - Abstract Book

S2285

Interdisciplinary – Health economics & health services research

ESTRO 2025

and that no important aspects of PSIs are lacking. The set can be used to design a questionnaire to assess PS in radiation oncology and guide radiation oncology professionals in establishing safer healthcare pathways and processes.

Keywords: Patient safety, Delphi study, Safety Indicators

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Digital Poster Clinicians’ Perspectives on Stereotactic Body Radiotherapy (SBRT) for Oligometastatic Breast Cancer: Findings from an International Survey Sukhdeep K Nagpal 1,2 , Sebastian M Christ 3 , Alison Ranger 1 , Gillian Ross 1,2 , Anna M Kirby 1,2 1 Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom. 2 Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom. 3 Department of Radiation Oncology, University Hospital & University of Zurich, Zurich, Switzerland Purpose/Objective: Conflicting evidence on the survival benefits of SBRT in oligometastatic breast cancer (OMBC) creates uncertainty regarding its clinical application. This survey explores global referral patterns and treatment approaches for SBRT in OMBC to inform future clinical trial design. Material/Methods: A cross-sectional international survey was conducted between April and July 2024 to gather clinician perspectives on SBRT for OMBC. Responses were collected via Microsoft Forms from oncologists and breast surgeons. Quantitative data were analysed descriptively in Excel, and qualitative responses thematically using NVivo 12. Results: A total of 304 clinicians from 42 countries participated, including 42% medical oncologists, 26% radiation oncologists, 20% clinical oncologists, and 11% breast surgeons. Seventy percent had over 10 years of breast oncology experience. Geographically, 68% were from Europe and 19% from Asia, with the highest representation from the United Kingdom (21%), Spain (17%), and Japan (11%). Survey responses show that 90% of clinicians believe SBRT has a role in metachronous OMBC and 79% in synchronous OMBC. SBRT is available at 88% of centres for metachronous and 77% for synchronous OMBC. Among centres offering SBRT for metachronous OMBC, 80% provide it as standard care, while 8% offer it only privately. For synchronous OMBC, 64% provide it as standard care, and 13% offer it privately. Where SBRT was unavailable, 51% referred patients to alternative centres. Luminal A was the most treated subtype with SBRT for both metachronous (92%) and synchronous (83%) OMBC, while triple-negative breast cancer was the least treated (74% for metachronous and 61% for synchronous). Spinal metastases were most treated with SBRT (96% for metachronous, 90% for synchronous), while liver and nodal metastases were treated less frequently (63% and 69%, respectively). Clinicians ranked local control (LC) as the top priority for metachronous OMBC and progression-free survival for synchronous OMBC. Regarding future perspectives, most clinicians (78% for metachronous and 69% for synchronous) anticipate an increased role for SBRT. A majority expressed a preference for recruiting to randomised controlled trials (RCTs) over prospective cohort studies, regardless of the oligometastatic setting (73% for metachronous and synchronous OMBC, 70% for oligoprogressive disease). Conclusion: Clinicians support the use of SBRT in OMBC, particularly for metachronous disease, where it is standard of care in many centres. Clinicians express a clear preference for RCTs over prospective cohorts to further define SBRT's role.