ESTRO 2025 - Abstract Book

S2298

Interdisciplinary – Health economics & health services research

ESTRO 2025

1 Department of Radiation Oncology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland. 2 Department of Economics, Ludwig Maximilian University of Munich (LMU), Munich, Germany. 3 ifo Institute, ifo Institute, Munich, Germany Purpose/Objective: Geographic access to oncological facilities remains a critical challenge in global cancer care. Previous studies have demonstrated that increased travel time to oncological facilities decreases both treatment participation rates and the number of outpatient appointments, particularly when travel time exceeds 120 minutes [1,2]. Studies specific to radiotherapy access in the United States, United Kingdom, and Sub-Saharan Africa have revealed substantial geographic disparities between regions, with rural and low-income areas facing the greatest barriers to access [1,3,4]. This study aims to: (1) quantify current global geographic accessibility to radiation oncology centers and (2) determine optimal locations for new facilities to maximize population coverage within a 120-minute threshold. Material/Methods: We conducted a geospatial analysis combining (1) worldwide radiotherapy center locations from the International Atomic Energy Agency (IAEA) Directory of Radiotherapy Centres (DIRAC), (2) administrative boundaries for 178,000 subregions from the Database of Global Administrative Areas (GADM), (3) population density data from WorldPop, and (4) global road network data from OpenStreetMap. For each administrative subregion, we calculated the population and drive time to the nearest radiotherapy center. Using a p-median optimization model, we iteratively identified optimal locations for 1 to 500 new centers to maximize population coverage within 120 minutes of travel time. Results: Currently, 57% of the global population has access to radiotherapy within 60 minutes, 76% within 120 minutes, and 84% within 180 minutes, with significant disparities between countries (population-weighted Gini coefficient = 0.63). The median travel time varies by country income group: 298 minutes in lower-middle-income countries, 103 minutes in upper-middle-income countries, and 36 minutes in high-income countries. This travel time is negatively correlated with gross domestic product (GDP) per capita (Spearman correlation -0.39 [95% CI: -0.20 to -0.48], p<0.001). Figure 1 presents the median travel time to radiotherapy centers worldwide.

Our optimization model shows that establishing 100 new radiotherapy centers in the most neglected regions would increase the population with 120-minute access from 76% to 81% (Figure 2), reducing the population-weighted Gini coefficient from 0.63 to 0.50. To provide 120-minute access to 85% of the world’s population, 370 new centers would be needed, with 189 (51%) located in low and lower-middle-income countries.