Radiotherapy centres and catchment areas
A list of radiotherapy centres in Canada was obtained from The Directory of Radiotherapy Centres (DIRAC), an online international registry of radiotherapy centres maintained by the International Atomic Energy Agency (IAEA). It includes approximately 90% of existing radiotherapy facilities worldwide, and is updated daily with information provided to the IAEA by radiotherapy centres or national organisations. Equipment and centres that are no longer operational are recorded as non-operational, rather than being deleted from the database. For this study, we filtered the database to include only radiotherapy centres and equipment that were operational in 2012, to most closely match the time period of our other data sets.