Diagnostic reference levels for 18F‐FDG whole body PET/CT procedures: Results from a survey of 12 centres in Australia and New Zealand

Introduction The aim of this work is to report diagnostic reference levels (DRLs) for hybrid positron emission tomography and x‐ray computed tomography (PET/CT) exams in Australia (AU) for Queensland (QLD) and Western Australia (WA) (AU QLD/WA) and New Zealand (NZ). Methods Two‐structured booklets were designed to collect dose information, patient demographics, equipment details and acquisition protocols for fluoride‐18 fluorodeoxyglucose (18F‐FDG) PET/CT procedures, and any additional diagnostic CT routinely performed as part of 18F‐FDG whole‐body examination. The DRL was reported based on the 75th percentile and achievable dose for 18F‐FDG, CT dose index volume (CTDIvol) and dose length product (DLP). The effective dose and total effective dose was reported for 18F‐FDG whole‐body PET/CT examination. Also, the effective dose was reported separately for identified additional diagnostic CT. Results The findings of this study show that the current DRL for 18F‐FDG in AU QLD/WA and NZ was 333.75 MBq and 332.87 MBq, respectively. The reported AU QLD/WA CTDIvol and DLP associated with 18F‐FDG whole‐body PET/CT examinations from vertex to thigh (VT) was 4.41 mGy and 474 mGy.cm. In NZ, the reported VT CTDIvol and DLP was 13.07 mGy and 1319.05 mGy.cm. The effective dose for 18F‐FDG and CT component was 5.6 mSv and 4.7 mSv for AU QLD/WA. For NZ, the effective dose was 5.7 mSv and 10.9 mSv for 18F‐FDG and CT component. The total effective dose delivered from the 18F‐FDG whole‐body scan from the AU QLD/WA PET/CT centres (10.44 mSv) were lower than the radiation doses delivered from the NZ (16.65 mSv). Conclusions The current DRLs were proposed for AU QLD/WA and NZ for 18F‐FDG whole‐body PET/CT examinations. Variations existed in the current practice of AU QLD/WA and NZ PET/CT examinations. There is a need to optimize the radiation doses delivered from PET/CT examinations.