Radionuclide calibrator intercomparison study of clinical PET centres in England to a single traceable 68Ge syringe source

Nucl Med Commun. 2020 Sep;41(9):965-976. doi: 10.1097/MNM.0000000000001241.


Objectives: The aim of this study was to characterize national variation in radionuclide calibrator activity response to a single National Institute of Standards and Technology (NIST) traceable reference Ge source used as a surrogate for F at clinical PET centres in England using National Physical Laboratory approved techniques.

Methods: Readings from 20 instruments at 13 centres using local F and Ge factor settings were recorded with the source located in vial and syringe positions. Ten repeat measurements were conducted to investigate repeatability using % coefficient of variability (COV). Comparison ratios to investigate accuracy were made between calibrator responses and decay-corrected NISTref reference activity for syringe and vial position measurements.

Results: The maximum %COV was 0.79%, while 90, 95 and 80% of calibrators conformed to 5% accuracy for F syringe, Ge syringe and Ge vial position readings, respectively. We revealed a trend towards reduced bias in measurements using Veenstra devices for F and using Capintec devices for Ge factor settings.

Conclusions: This study demonstrated good repeatability in local device measurements. In total, 70% of English calibrators tested and 88% of all measurements performed achieved 5% accuracy. While statistically significant bias was exhibited between different vendor equipment dependent upon radioisotope selected, our study recommends regular traceability checks for optimum instrument performance conducted within National Metrology Institutes guidelines.

Publication types

  • Comparative Study

MeSH terms

  • Algorithms
  • Calibration
  • England
  • Fluorine Radioisotopes / analysis
  • Germanium*
  • Humans
  • Phantoms, Imaging
  • Positron-Emission Tomography / standards*
  • Radioisotopes*
  • Radiopharmaceuticals / analysis*
  • Reference Standards
  • Reproducibility of Results
  • Syringes


  • Fluorine Radioisotopes
  • Radioisotopes
  • Radiopharmaceuticals
  • Germanium