50 years of the IAEA/WHO postal dose audits for radiotherapy

For more than 40 years the IAEA has operated a service to validate the calibration of radiotherapy beams in low and middle income countries using the IAEA/WHO TLD postal dose audit service. This service provides a quality audit of the dose delivered by radiotherapy treatment machines using a thermoluminescent dosimeter (TLD) as a transfer dosimeter. The IAEA is responsible for the technical aspects of the service, whereas the World Health Organization (WHO) help with the local organization and distribution of TLDs to radiotherapy centres in various countries. Hospital staff irradiate the dosimeters with a prescribed dose under known irradiation conditions and return them to the IAEA for evaluation. The dose given to the dosimeters is determined at the IAEA Dosimetry Laboratory and the result is compared with the dose stated by radiotherapy staff