A population-based prospective database targeting 15 key radiation therapy (RT) features was initiated in British Columbia in 1984. This 25-year outcome report assessed the utility of the database and demonstrated that such a database can be used to (1) describe population-based utilization of a health service, (2) inform treatment policy recommendations, (3) inform system planning and resource allocation, (4) audit regional and individual oncology practices, (5) assess whether new observations from randomized trials have been translated into population health gains and (6) produce peer-reviewed publications. Health system managers and researchers could benefit from the development and support of such databases.