ESTRO 2024 - Abstract Book

S144 ESTRO 2024 Background and Purpose: Target delineation in glioblastoma remains a matter of extensive research and debate. The present guideline published in 2023 aims to update the existing joint European consensus on delineation of the clinical target volume (CTV) in adult glioblastoma patients. Material and Methods: The ESTRO Guidelines Committee identified 14 European experts in close interaction with the ESTRO clinical committee and EANO who discussed and analysed the body of evidence concerning contemporary glioblastoma target delineation, then took part in a two-step modified Delphi process to address open questions. Results: The guideline addresses key aspects such as pre-treatment procedures, target delineation with both traditional and novel imaging methods, and treatment details such as constraints and fractionation. Recommendations include focusing on the surgical cavity and remnants, suggesting a reduced 15 mm margin. Specific focus was placed on how to consider FLAIR imaging during target definition. Conclusions: The consensus advocates for CTV definition centered on post-surgical contrast-enhanced T1 images, with uniform margins and no need for further reduction. It recommends a Planning Target Volume (PTV) margin, typically up to 3 mm, tailored to the individual's mask system and Image-Guided Radiation Therapy (IGRT) protocols. Invited Speaker Matthias Guckenberger 1,2 , Nicolaus Andratschke 1 , Claus Belka 3 , David Bellut 1 , Francesco Cuccia 4 , Max Dahele 5 , Ricarda Guninski 1 , Mirjana Josipovic 6 , Pietro Mancosu 7 , Giuseppe Minniti 8 , Maximilian Niyazi 9 , Umberto Ricardi 10 , Per Munck af Rosenschold 11 , Arjun Sahgal 12 , Yat Tsang 13 , Wilko Verbakel 14 , Filippo Alongi 15 1 University Hospital Zurich, Department of Radiation Oncology, Zürich, Switzerland. 2 University of Zurich, Department of Radiation Oncology, Zurich, Switzerland. 3 University Hospital LMU Munich, Department of Radiation Oncology, Munich, Germany. 4 ARNAS Civico Hospital, Radiation Oncology Unit, Palermo, Italy. 5 Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Radiation Oncology and Cancer Center Amsterdam, Amsterdam, Netherlands. 6 Copenhagen University Hospital, Deparment for Oncology, Centre for Cancer and Organ Diseases, Copenhagen, Denmark. 7 IRCCS Humanitas Research Hospital, Medical Physics Unit, Radiation Oncology department, Milan, Italy. 8 Oncology and Anatomical Pathology Sapienza University of Rome, Department of Radiological Sciences, Rome, Italy. 9 University Hospital Tübingen, Department of Radiation Oncology, Tübingen, Germany. 10 University of Turin, Department of Oncology, Turin, Italy. 11 Rigshospitalet, Radiation Medicine Research Center, Copenhagen, Denmark. 12 Odette Cancer Center of the Sunnybrook Health Sciences Center, Department of Radiation Oncology, Toronto, Canada. 13 Princess Margaret Cancer Center, Radiation Medicine Program, Toronto, Canada. 14 Amsterdam University Medical Center, Department of Radiation Oncology, Amsterdam, Netherlands. 15 IRCCS Ospedale Sacro Cuore Don Calabria, Advanced Radiation Department, Negrar-Verona, Italy 3615 ESTRO practice guideline: Stereotactic Body Radiotherapy for Spine metastases

Abstract:

Background and purpose

Recent progress in diagnostics and treatment of metastatic cancer patients have improved survival substantially. These developments also affect local therapies, with treatment aims shifting from short-term palliation to long-term