An update on 'dose calibrator' settings for nuclides used in nuclear medicine.

BACKGROUND: Most clinical measurements of radioactivity, whether for therapeutic or imaging nuclides, rely on commercial re-entrant ionization chambers ('dose calibrators'). The National Institute of Standards and Technology (NIST) maintains a battery of representative calibrators and works to link calibration settings ('dial settings') to primary radioactivity standards. Here, we provide a summary of NIST-determined dial settings for 22 radionuclides. METHODS: We collected previously published dial settings and determined some new ones using either the calibration curve method or the dialing-in approach. RESULTS: The dial settings with their uncertainties are collected in a comprehensive table. CONCLUSION: In general, current manufacturer-provided calibration settings give activities that agree with National Institute of Standards and Technology standards to within a few percent.