ESTRO 2025 - Abstract Book

S1677

Clinical - Sarcoma & skin cancer & malignant melanoma

ESTRO 2025

common cancers as pattern of spread may be different from their more common counterparts. These basic observations are especially important in developing countries with inadequate staging resources.

Keywords: distant spread, lymph node, Merkel cell carcinoma

1638

Proffered Paper The Sarcoma Ring Trial: A case-based analysis of inter-center agreement across 21 German-speaking sarcoma centers Siyer Roohani 1,2,3 , Jolina Handtke 1 , Kamal Hummedah 4 , Markus Albertsmeier 5 , DImosthenis Andreou 6,7 , Sebastian Bauer 8 , Anna Duprée 9 , Franziska Eckert 10,11 , Christina Jentsch 12 , Johanna Kirchberg 13 , Lars H Lindner 14 , Vlatko Potkrajcic 15 , Peter Reichardt 16 , Jana Käthe Striefler 17 , Katharina Seidensaal 18,19,20 , Sabine Semrau 21 , Beate Timmermann 22 , David Kaul 1,23 , Jens Jakob 24 1 Department of Radiation Oncology, Charité Universitätsmedizin Berlin, Berlin, Germany. 2 BIH Charité (Junior) Clinician Scientist Program, Berlin Institute of Health, Berlin, Germany. 3 Partner Site Berlin, German Cancer Consortium (DKTK), Berlin, Germany. 4 Department of Surgery, University Medical Center and Medical Faculty Mannheim, Mannheim, Germany. 5 Department of General, Visceral and Transplantation Surgery, Ludwig Maximilians-Universität (LMU) Munich, Munich, Germany. 6 Department of Orthopedic Oncology, West German Cancer Center, University Hospital Essen, Essen, Germany. 7 Department of Orthopedics and Trauma, Medical University of Graz, Graz, Austria. 8 Department of Medical Oncology and Sarcoma Center, West German Cancer Center, University Duisburg-Essen, Medical School, Essen, Germany. 9 Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. 10 Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany. 11 Department of Radiation Oncology, AKH, Comprehensive Cancer Center Vienna, Medical University Vienna, Vienna, Austria. 12 Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden, Germany. 13 Department of General, Visceral, Thoracic and Vascular Surgery, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden, Germany. 14 SarKUM, Center of Bone and Soft Tissue Tumors, LMU University Hospital, Munich, Germany. 15 Department of Radiation Oncology,, University Hospital Tübingen, Tübingen, Germany. 16 Sarkomzentrum, Helios Klinikum Berlin Buch, Berlin, Germany. 17 Department of Internal Medicine II, Oncology/Hematology/BMT/Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. 18 Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany. 19 Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany. 20 NCT, National Center for Tumor Diseases, Heidelberg, Germany. 21 Department of Radiation Oncology, University Hospital Erlangen, Erlangen, Germany. 22 Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), Essen, Germany. 23 HMU, Health and Medical University Potsdam, Potsdam, Germany. 24 Sarcoma Unit, Department of Surgery, University Medical Center and Medical Faculty Mannheim, Mannheim, Germany Purpose/Objective: The management of soft tissue sarcoma (STS) at reference centers with specialized multidisciplinary tumor boards (MTB) improves patient survival. The German Cancer Society (DKG) certifies sarcoma centers in German-speaking countries, promoting high standards of care. This study investigated the variability in treatment recommendations for localized STS across different German-speaking tertiary sarcoma centers. Material/Methods: In this cross-sectional case-based survey study, 5 anonymized patient cases with imaging data of localized STS were presented to MTBs of 21 German-speaking tertiary referral hospitals. Centers provided recommendations on treatment sequence and modalities, along with the consensus level within their MTB. Agreement percentages were calculated, and consensus levels were rated on a scale of 1 to 10.