The establishment of national diagnostic reference levels for adult SPECT-CT in Saudi Arabia.

This study aims to introduce national diagnostic reference levels (NDRLs) for adult hybrid single photon emission computed tomography (SPECT-CT) in nuclear medicine (NM) departments in the Kingdom of Saudi Arabia. The administered activity (AA) of radiopharmaceuticals, volume-weighted computed tomography dose index (CTDIvol) and dose length product (DLP) for ten hybrid SPECT/CT examinations were collected and analysed for one year. The median of AA, CTDIvoland DLP for each dose quantity was derived and the suggested national DRLs were determined based on the 75thpercentile for all identified SPECT-CT examinations. A comparison of the defined adult NDRLs in Saudi Arabia with the published data of other countries was performed. Although there are no significant variations of the proposed NDRL of AA between countries, the proposed NDRLs of the integrated CT metrics exceed the published data in most procedures. NM departments are urged to consider optimisation for both image quality and radiation protection.

Diagnostic reference levels for 18 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 (18 F-FDG) PET/CT procedures, and any additional diagnostic CT routinely performed as part of 18 F-FDG whole-body examination. The DRL was reported based on the 75th percentile and achievable dose for 18 F-FDG, CT dose index volume (CTDIvol ) and dose length product (DLP). The effective dose and total effective dose was reported for 18 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 18 F-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 18 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 CTDIvol and DLP was 13.07 mGy and 1319.05 mGy.cm. The effective dose for 18 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 18 F-FDG and CT component. The total effective dose delivered from the 18 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 18 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.

Determining and updating PET/CT and SPECT/CT diagnostic reference levels: A systematic review.

The aim of this systematic review is to investigate the national diagnostic reference level (NDRL) methods for positron emission tomography/computed tomography (PET/CT) and single photon emission tomography/computed tomography (SPECT/CT) procedures. A search strategy was based on the preferred, reporting items for systematic review and meta-analysis (PRISMA). Relevant articles retrieved from Medline, Scopus, Web of Science, Embase, Cinahl, and Google Scholar published up to October 2017. The search yielded 1057 articles. Fourteen articles were included in the review after a screening process. Relevant information from the selected articles were summarised and analysed. Discrepancies were found between the methodologies utilised to establish and report both PET/CT and SPECT/CT NDRLs, e.g. patient sampling and administered activity. Further research should focus on reporting more NDRLs for hybrid PET/CT and SPECT/CT examinations, and establish a robust NDRL standard for the CT portion associated with PET/CT and SPECT/CT examinations. This review provides updated NDRL reommndations to deliver more comparable international radation doses for administered activity and CT dose across PET/CT and SPECT/CT clinics.