ESTRO 2025 - Abstract Book

S2389

Interdisciplinary – Other

ESTRO 2025

3128

Mini-Oral E2-RADIatE: ESTRO-EORTC collaborative platform to collect real-world evidence, supporting European radiotherapy practice and research (NCT-03818503). Yolande Lievens 1,2 , Nicolaus Andratschke 3 , Eralda Azizaj 4 , Enrico Clementel 5 , Chiara Gasparotto 4 , Matthias Guckenberger 3 , Denis Lacombe 5 , Sarah Nuyens 5 , Felix Oppong 5 , Piet Ost 2,6 , Joachim Widder 7 , Jonas Willmann 3,8 , Damien Charles Weber 9 1 Radiation Oncology Department, Ghent University Hospital, Ghent, Belgium. 2 Department of Human Structure and Repair, Ghent University, Ghent, Belgium. 3 Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland. 4 Headquarters, European Society for Radiotherapy and Oncology, Brussels, Belgium. 5 Headquarters, European Organisation for Research and Treatment of Cancer, Brussels, Belgium. 6 Radiation Oncology Department, Iridium Netwerk, Antwerp, Belgium. 7 Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria. 8 Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA. 9 Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland Purpose/Objective Facing rapid advancements in radiation oncology, research must integrate real-world evidence (RWE) to assess the clinical effectiveness of new radiotherapy interventions 1,2 . This report details the E²-RADIatE platform, designed to support radiotherapy research and demonstrate the role of this treatment modality within the framework of multidisciplinary cancer care. Material/Methods Established in 2019, E²-RADIatE (EORTC-ESTRO RADiotherapy Infrastructure for Europe - EORTC 1811 study - NCT03818503) is a collaboration between the European Organisation for Research and Treatment of Cancer (EORTC) and the European Society for Radiotherapy and Oncology (ESTRO). The platform uses prospective data registries within a multi-cohort study format to collect RWE across Europe. Each cohort targets specific radiotherapy indications or techniques, pooling data in a single database that simplifies regulatory and data collection processes. This infrastructure allows streamlined data capture from both academic and non-academic European centers, ensuring broad participation and data diversity. Results On 01/10/2024, 60 centres in 14 countries were actively recruiting patients in one or both active E²-RADIatE cohorts. OligoCare, the first cohort opened in June 2019, evaluates radical metastasis-directed radiotherapy in oligometastatic (OMD) patients with breast, lung, prostate or colorectal cancer. With 58 centres active, 3025 patients were included. Initial publications illustrated how stereotactic body radiotherapy (SBRT) doses vary by primary cancer and oligometastatic location, higher doses being delivered to lung and liver lesions 3 ; that acute grade ≥3 SBRT-related toxicity is limited to 0.5 % within 6 months, confirming the safety of SBRT in the real-life management of OMD 4 and that quality-of-life remains unaffected 6 months after SBRT for OMD in prostate cancer 5 . Overall survival analysis is ongoing. Data showing that less than 10% of patients receive single-fraction SBRT prompted the initiation of the first international TWICS (Trials WithIn Cohorts Study) in radiotherapy, comparing single- and multi fraction SBRT. A second cohort, ReCare, initiated in June 2023 (310 patients enrolled in 14 centres, 12 of which also enrolling patients in OligoCare), examines the increasingly important relevance of re-irradiation. A third cohort AlphaCare is currently being developed to investigate the toxicity of combining novel drugs with high dose radiotherapy. Conclusion E²-RADIatE illustrates that RWE collection can clarify radiotherapy practices across Europe, complementing randomized trials, generating hypotheses and advancing research through innovative methodologies. Achievements are due to the collaboration between EORTC and ESTRO and the active participation of the European