Diagnostic reference levels for F-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 ( F-FDG) PET/CT procedures, and any additional diagnostic CT routinely performed as part of F-FDG whole-body examination. The DRL was reported based on the 75 percentile and achievable dose for F-FDG, CT dose index volume (CTDI ) and dose length product (DLP). The effective dose and total effective dose was reported for F-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 F-FDG in AU QLD/WA and NZ was 333.75 MBq and 332.87 MBq, respectively. The reported AU QLD/WA CTDI and DLP associated with F-FDG whole-body PET/CT examinations from vertex to thigh (VT) was 4.41 mGy and 474 mGy.cm. In NZ, the reported VT CTDI and DLP was 13.07 mGy and 1319.05 mGy.cm. The effective dose for F-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 F-FDG and CT component. The total effective dose delivered from the F-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 F-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.