A survey of gamma camera and SPECT/CT quality control programs across a sample of public hospitals in Australia

Abstract

Abstract The performance testing of gamma cameras and single photon computed tomography/computed tomography (SPECT/CT) systems is not subject to regulatory requirements across states and territories in Australia. Internationally recognised testing standards from organisations such as the National Electrical Manufacturers Association (NEMA) describe methodologies for tests that are recommended to be performed. However, variations exist in suggested quality control (QC) schedules from professional bodies such as the Australia and New Zealand Society of Nuclear Medicine (ANZSNM) and the European Association of Nuclear Medicine (EANM). In this study, a survey was conducted to benchmark current QA programs across a selected sample of eight standalone and networked Australian public hospitals. All participating sites had nuclear medicine technologists performing daily vendor-specific flood-field uniformity (intrinsic or extrinsic/system) verification without photomultiplier (PMT) tuning and CT QC. Weekly and monthly PMT tuning followed by intrinsic flood-field verifications were performed at most sites. At least half of the sites performed monthly centre of rotation (COR) offset verifications. SPECT/CT alignment calibrations and verifications were undertaken by service engineers at all sites, and periodic verifications by local medical physicists were performed on an ad-hoc basis at three sites and yearly at another site. Variations were observed for other periodic QC tests such as intrinsic/system spatial resolution, uniformity verifications using off-peak energy windows, planar sensitivity, multiple window spatial resolution, whole-body spatial resolution and count rate variability tests, SPECT image quality, spatial resolution, uniformity and sensitivity variability. Non-mandatory periodic compliance testing of the CT component of the hybrid SPECT/CT systems was performed at four sites. The survey also documented that most of the sites checked daily and periodic QC results against pass/fail criteria set by vendors. Additional analyses of the QC results, including trend analysis and periodic reviews, were not common practice and differed across the participating sites.