DATA COLLECTION METHODOLOGY
Data on radiation therapy facilities contained in the DIRAC database are obtained from various sources and they are continuously updated with the voluntary collaboration of radiotherapy centres and clinical institutions spread all over the world. Once data are collected and shared with the DIRAC Team, they undergo a process of data review and verification for any inconsistencies and completeness.
Professionals working in any radiotherapy centre can ask for credentials to enter data of their institutions to DIRAC, either online or offline, through electronic questionnaires. Online data entry can be done anytime to introduce modifications and updates or report on changes in the facility.
NATIONAL DIRAC COORDINATORS
Starting in 2015, the IAEA Member States were requested to nominate national representatives to act as DIRAC Coordinators with the aim to collect national data on radiotherapy infrastructure and transfer them to DIRAC.
THE IAEA/WHO POSTAL DOSE AUDIT SERVICE
The IAEA in conjunction with WHO (PAHO in Latin America and the Caribbean) operates a mailed dosimetry audit programme for radiotherapy centers worldwide. The up-to-date administrative data of the centers as well as data on teletherapy equipment used for irradiation of IAEA dosimeters are verified and synchronized regularly with the DIRAC database.
THIRD PARTY DATA COLLECTION
Various organizations (national authorities for radiation safety, Secondary Standards Dosimetry Laboratories, organizations conducting dosimetry audit programmes or professional societies) in different countries maintain registries or databases on radiotherapy services and equipment. Reports from these organizations are reviewed and included in DIRAC.
OTHER SOURCES OF DATA
The membership directories of scientific or professional societies are used for establishing contacts with individual hospitals in order to update their DIRAC data. IAEA staff and experts traveling on missions with tasks related to radiation oncology or medical radiation physics collect information for DIRAC. This includes fact-finding, country profile or cancer control assessment missions (imPACT missions), advisory and technical missions, and Quality Assurance Team for Radiation Oncology (QUATRO) missions. Participants in IAEA organized training courses are individually contacted and requested to update data for their centres in DIRAC.
DIRAC data are collected based on the voluntary contribution of collaborators across the world working in the field of radiotherapy. Although the IAEA has systems for quality control in place to ensure the maximum level of consistency regardless of the data source, accuracy is strongly dependent on the initial input provided by the DIRAC collaborators. The radiotherapy centres in DIRAC have had their data included at various periods since the inception of DIRAC. As there might be other radiotherapy centres providing radiation therapy to cancer patients worldwide that are not included in DIRAC, the list of centres should not be considered complete. Furthermore, the absence of specific data for a given country or a centre does not automatically determine that this particular country or centre is not equipped for provision of radiotherapy services, thus, global, regional and national conclusions using DIRAC data should be done taking into account those considerations.