Optimising 18F-FDG PET/CT image quality and radiation dose in Jordan: establishing diagnostic reference levels and assessing knowledge among medical imaging professionals

Abstract

Positron emission tomography/computed tomography (PET/CT) advances cancer imaging by providing detailed functional and anatomical data. However, concerns regarding radiation have increased, necessitating the evaluation of radiation dosages administered to patients undergoing PET/CT. The diagnostic reference level (DRL) is an optimisation tool that can potentially reduce radiation doses. The main objective of the study was to assess medical imaging professionals’ (MIPs) knowledge, establish national DRLs (NDRLs) and optimise radiation dose and image quality for oncological 18F-FDG PET/CT imaging in Jordan. The study was conducted in three stages. The first stage involved assessing MIPs knowledge of DRLs, radiation dose and image quality through a cross-sectional study. The second stage established DRLs for adult and paediatric oncology patients for 18F-FDG PET/CT. The final stage used a phantom experimental study to optimise the radiation dose by adjusting the protocol parameters while maintaining image quality. Participants demonstrated moderate knowledge of dose and protocol parameters (61.8%) but lower levels in image quality (49.2%) and DRLs (44.8%). In addition, significant differences were noted among age and experience groups with respect to the knowledge of dose and protocol parameters; and age groups towards DRL knowledge (p < 0.05). NDRLs were successfully established for adult and paediatric oncology 18F-FDG PET/CT imaging in Jordan, with DRL dose quantities varying across the participating scanners. In the phantom study, protocols A3, A4, P10 and P15 were identified as optimal through subjective and objective assessments, achieving radiation dose reductions of 32.4%, 43.2%, 56.7% and 66.7%, respectively, while preserving diagnostic accuracy and image quality compared to NDRLs. In conclusion, various countries have exhibited unique trends in utilising DRLs as an optimisation tool in PET/CT imaging. Thus, it is recommended that MIPs participate in educational and training programs that focus on the impact of exposure parameters and DRL applications. This study offers a valuable tool for Jordanian PET/CT centres, facilitating the comparison of their local DRLs against the proposed NDRLs. Furthermore, the results of the phantom study provide a key reference for optimising clinical practice, particularly for CT radiation doses.