DRLs for CT used in PET/CT examinations are limited. The study proposes a NDRL for CT part in KW, in support of optimisation and dose reduction. All the PET/CT centers (No:7) participated in the study and only adult oncology patients were collected as the other studies were limited. The CTDIvol, DLP and SL were recorded and the Median, Mean, SD, 75th, 25th percentiles as well as WB effective dose (ED) were calculated. Dose and scan length statistics for HB and WB scans (53% and 47% of total: 197) and the WB+HB presented together with the proposed NDRLs and the Achievable doses. There were variations in proposed and achievable local DRL amongst 7 centers, highlighting the need for NDRL. Third quartile DLP (mGy x cm) and CTDIvol (mGy) values for the HB were (556, 5.5) which were higher than the UK NDRL (400, 4.3) but were lower than the Swiss NDRL (620, 6) and the France NDRL (762, 7.7). Comparatively, the Proposed NDRLs for (WB) were (677, 4.2) which were lower than Swiss National Data (720, 5.0). It is worth noted that, Swiss had about 5000 (HB) & 706 (WB), UK had 370 (HB) and France had 1000 (HB) entries. Calculated ED varied from 4.6 to 13mSv, (mean values=8.4 mSv) for HB and from 4.5 to 8.4 mSv (mean value=5.6 mSv) for WB scans. The study demonstrated the need for national CT DRLs for PET/CT as part of the state of the KW strategy for improving the national health services.
