Diagnostic Reference Levels for conventional radiography and fluoroscopy in Austria: Results and updated National Diagnostic Reference Levels derived from a nationwide survey

•Evaluating and updating Austrian NDRLs for conventional radiography and fluoroscopy.•Findings of this study are substantially lower than the old Austrian NDRLs (valid till early 2018).•Findings of this study correspond well to European NDRLs. Evaluation and updating of Austrian National Diagnostic Reference Levels (NDRLs). A nationwide survey on common conventional radiography and fluoroscopy examinations was conducted. In line with Austrian radiation protection standards, all relevant Austrian hospitals and radiology offices/centers were asked to report a minimum sample of 10 representative dose-area product (DAP) values together with patient weight and fluoroscopy time, if applicable. Examinations included for conventional radiography were skull, chest, abdomen, pelvis, lumbar spine and bedside chest x-ray, for fluoroscopy barium enema (single and double contrast) and swallowing (video). Participants were invited via e-mail, followed up by reminders to increase participation rates. Plausibility checks were performed to increase data quality. 3rd quartiles of facility median and mean DAP were calculated and compared to Austrian and international NDRLs. 59% of invited facilities submitted DAP data, 43% submitted additional data on patient weight and 41% on fluoroscopy time. DAP case numbers varied from 1005 to 2121 for conventional radiography and from 182 to 1380 for fluoroscopy. Average patient weight was 75 kg for conventional radiography and 77 kg for fluoroscopy. 3rd quartiles derived from the survey are substantially lower than the old Austrian NDRLs (valid till early 2018). Since 3rd quartiles correspond well to European NDRLs, the update would be in accordance with European DRL harmonisation efforts.