Calibration factors for commercial ionization chambers (i.e. dose calibrators) were determined for a solution of 123I; the activity was based on the 1976 NBS standard. A link between the NIST standard and the International Reference System (SIR) was established. The two major U.S. dose calibrator manufacturers recommend oppositely biased calibration factors, giving a spread of 11.3 % in measured activities. With modern quantitative imaging techniques capable of ≤ 10 % accuracy, this bias for a SPECT nuclide is highly significant.
Citation: Applied Radiation and Isotopes
Pub Type: Journals
Ionization chamber, dose calibrator, I-123, secondary standard, quantitative imaging