A 3-year national DRL for CT in hybrid imaging study in Kuwait health environment—impact and implementation

Abstract

Objective DRLs for CT (PET-CT) are limited. Published DRLs may not be directly relevant to the state of Kuwait (KW). We aimed to execute the final phase of 3 years study of the DRL in KW, in support of optimisation and dose reduction as imaging technology is advancing. Methods In this cohort study with participation of 8 PET-CT centers, 400 adult oncology patients were collected as per phases 1 and 2 due to a limited number of the other studies and as per MOH Ethical Committee recommendation. The CTDIvol, DLP and scan length were recorded, and the Median, Mean, SD, 75th, 25th percentiles as well as WB effective dose (ED) were calculated. Comparative studies were also presented to track implementation and shortfall. Results In this study, half body (HB) and whole body (WB) scan accounted for 66% and 34% of the total (400). There were 25% maximum variations in proposed local DRL in practice between 8 centers in 2022 study with an improvement of 30% over 2020. The achievable local DRL remained the same as 2022. The comparative results of the third quartile DLP (mGy x cm) and CTDIvol (mGy) values for 2018, 2020 and 2020 suggested lower values for the third phase (400 entries) with 1.5-fold variation in DLP. The calculated ED varied from 2.6 to 7.1 mSv, mean values = 4.7 ± 1.25 mSv for WB (K=.0093 mSv/mGy/cm). The 2022 Proposed NDRLs for the HB (490, 4.5) were lower than Swiss National Data (620, 6.0), France (662, 6.8) but slightly higher than UK though, the Swiss had about 5000, France had 1000 and the UK had 370 HB entries. Conclusions There was a 11.1% continuous improvement in NDRL for 2022 compared to 9.1% in 2020, demonstrating a trend of improved optimization. Advances in Knowledge Data provided a trend of NDRL that is served as a national data bank for continuous optimisation.