Results of the 1972 CAP/NBS study of radionuclide measurements

In 1972 a pilot study was carried out to evaluate radioactivity assay procedures for in-vivo administration in nuclear medicine. The plan was to determine the accuracy with which a measured quantity of radioactivity can be administered to a patient. Delivered samples were returned to the National Bureau of Standards by 33 participants. The activity values of 47% of the participants were within plus or minus 10% and 81% were within plus or minus 20% of the activity value of the samples subsequently measured by the National Bureau of Standards. The analysis of the variability indicated that many of the difficulties encountered by the participants were due to two factors outside their control: differences in assay values of chromium-51 between radiopharmaceutical companies and poor calibration or instruction by the manufacturers of dose calibrators.