Experimental determinations of commercial 'dose calibrator' settings for nuclides used in nuclear medicine

Commercial reentrant ionization chambers ('dose calibrators') have become t he de facto standard instrument for making radioactivity measurements in th e radiopharmaceutical industry. Accurate activity measurements, however, de pend on the application of the correct calibration factor (dial setting) fo r the radionuclide in the exact measurement geometry for that particular in strument. Two methods are described for the experimental determination of d ial settings for the Capintec CRC-12 dose calibrator. Using these methods, we have determined new calibration factors for F-18, Cu-62, Re-186 and Re-1 88 in several geometries. These new factors are presented, along with previ ously determined settings, for nuclides commonly used in nuclear medicine. The differences between the calibration factors for the different geometrie s, as well as the differences between the manufacturer's recommended settin g underscore the need for empirically determined dose calibrator settings. Published by Elsevier Science Ltd.