Critical appraisal of radionuclide calibrators and gamma cameras prior to Lutetium-177 internal dosimetry at two south african hospitals

The functionality of radionuclide dose calibrator and nuclear medicine imaging systems has a direct effect on the accuracy and preciseness of internal dosimetry evaluations. Our study, therefore, aimed to critically appraise the radionuclide calibrators and gamma cameras prior to Lutetium-177 (¹⁷⁷Lu) internal dosimetry in a developing country. Two radionuclide calibrators' and three gamma cameras at two South African hospitals were critically appraised in preparation for internal dosimetry of ¹⁷⁷Lu. The radionuclide calibrators' accuracy, linearity, and sample volume abilities were appraised. For the three gamma cameras, the uniformity, energy resolution, center of rotation, and collimator sensitivity were appraised. These appraisals were performed between the years 2014 and 2019. The radionuclide calibrators' constancy, accuracy, linearity, and sample volume were within ± 5%. We also integrated a ¹⁷⁷Lu calibration factor into one radionuclide calibrator's library. The three gamma cameras' uniformity was within 2 to 5%, energy resolution within 11%, center of rotation within 2 mm, and the sensitivity recorded for all low energy high resolution collimator. Our radionuclide calibrators passed the critical appraisal and may be confidently used for assaying ¹⁷⁷Lu. All three cameras also passed critical appraisal and may be used to assess organ absorbed dose. (author)