IAEA/WHO 60Co teletherapy dosimetry service using mailed LiF dosimeters. A survey of results obtained during 1975-1982.

During 1975-1982 the International Atomic Energy Agency (IAEA) in co-operation with the World Health Organization (WHO) carried out 603 absorbed dose determinations for 60Co gamma-ray beams for 278 radiotherapy institutes in 60 countries. The participants were asked to irradiate capsules containing LiF powder to 2 Gy in 5 cm of water. The percentage of the determinations in which the deviation between the institutes quoted dose and the IAEA measured dose was within +/- 5% was 62%. In 17% of the determinations, the deviation was more than +/- 10%. For around 70% of the institutes the deviation decreased when further measurements were carried out.