Dose calibrator manufacturer-dependent bias in assays of ¹²³I

Denis E Bergeron; Jeffrey T Cessna; Daniel B Golas; Rheannan K Young; Brian E Zimmerman

doi:10.1016/j.apradiso.2014.03.018

Dose calibrator manufacturer-dependent bias in assays of ¹²³I

Appl Radiat Isot. 2014 Aug:90:79-83. doi: 10.1016/j.apradiso.2014.03.018. Epub 2014 Mar 26.

Authors

Denis E Bergeron¹, Jeffrey T Cessna², Daniel B Golas², Rheannan K Young², Brian E Zimmerman²

Affiliations

¹ Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8462, Gaithersburg, MD 20899-8462, USA. Electronic address: denis.bergeron@nist.gov.
² Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8462, Gaithersburg, MD 20899-8462, USA.

PMID: 24705009
DOI: 10.1016/j.apradiso.2014.03.018

Abstract

Calibration factors for commercial ionization chambers (i.e. dose calibrators) were determined for a solution of (123)I; 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.

Keywords: Dose calibrator; I-123; Ionization chamber; Quantitative imaging; Secondary standard.

Published by Elsevier Ltd.