ESTRO 2025 - Abstract Book

S2414

Interdisciplinary – Other

ESTRO 2025

4304

Poster Discussion Navigating Scientific Progress in Radiation Oncology – Comprehensive Analysis of Clinical Trials from 20 Years Using the ClinicalTrials.gov Database Sebastian M Christ 1,2 , Maksym Fritsak 1 , Gabriel Kobeissi 2 , Philip Heesen 3 , Siyer Roohani 4 , Rifaquat Rahman 5 , Ajay Aggarwal 6 , Matthias Guckenberger 1 1 Department of Radiation Oncology, University Hospital & University of Zurich, Zurich, Switzerland. 2 Department of Radiation Oncology, CHUV Lausanne, Lausanne, Switzerland. 3 Faculty of Medicine, University of Zurich, Zurich, Switzerland. 4 Department of Radiation Oncology, Charité - Berlin University Medicine, Berlin, Germany. 5 Department of Radiation Oncology, Dana-Farber Cancer Center, Boston, USA. 6 Department of Radiation Oncology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom Purpose/Objective Over the past two decades, the field of oncology has witnessed significant growth in clinical trial activity, yet a holistic examination of this landscape has been lacking (1–6). We therefore conducted a comprehensive analysis of publicly registered clinical trials, focusing on trials related to radiation therapy and cancer treatment. Material/Methods Publicly available data from ClinicalTrials.gov provided the basis for this study. All clinical trials registered on the database were screened, and 4,253 radiation oncology trials were included into this analysis. Trends in trial activity over time, distribution of trials by organ system, geographic location of trials, and phase of clinical trials were analyzed. Results Over the past 20 years, there was a trend to increased clinical trial activity in radiation oncology, leading to the registration of 4,253 comprehensively reported trials on ClinicalTrials.gov by February 8th, 2024. The most frequently investigated organ systems were digestive system, central nervous system, and head and neck, making up 2,113 (49.7%) of all studies. While oligometastasis emerged as newly studied disease entity over the last decade (n=95, 2.2%), hematology represented the only organ system where significant decreased trial activity was observed (n=413, 9.7%). The large majority of registered studies were phase II trials (n=2,181, 51.3%); most studies continue to emanate from North America (n=2,477, 58.2%), while Europe (n=903, 21.2%) and Asia (n=1,072, 25.2%) represent relevant and rising shares over time. Only about 6% radiation oncology trials received industry funding.