For 10 years, participating in national surveys is mandatory for all medical centres in Belgium with regular radiological activity. Dose data are collected annually for CT procedures and every three years for conventional radiography, mammography and interventional procedures by means of dedicated forms. Considered procedures are taken from an official list of common examinations. For each device, data must be collected for procedures performed for minimum 5 patients per month on average .
National DRLs are computed as the 75th percentile (P75) of the distribution...
Description of activity and work performed
For some CT and conventional radiology procedures, additional information collected during surveys allowed to differentiate between single-shot and multiphasic procedures, which was a first step towards considering the clinical indication. In particular, DRLs for CTDIvol were computed only from monophasic examinations while DRLs for DLP were computed for monophasic examinations (the dose for the “main” scan) and non-differentiated procedures (cumulative DLP).
DRLs and other percentiles of the distributions were continuously decreasing despite the relatively short period between surveys, but progressively stagnated for CT and mammography....
Conclusion and recommendations
Belgian DRLs were established on a regular basis for a large number of standard radiological procedures for adults and children. They were continuously decreasing but progressively stagnated for some CT procedures and mammography. They were similar to those of other European countries.
Asking for additional parameters during the data collection process was essential for establishing specific DRLs and potential ways of optimization and dose reduction such as considering separately single-shot and multiphasic procedures, types of detector for conventional radiography and mammography, or fluoroscopy time for...
T. Vanaudenhove; Federal Agency for Nuclear Control Brussels/BE - nothing to disclose
K. van Slambrouck; Federal Agency for Nuclear Control Brussels/BE- nothing to disclose
A. Fremout; Federal Agency for Nuclear Control Brussels/BE- nothing to disclose
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 European Commission (2014) Diagnostic Reference Levels in Thirty-six European Countries. Radiation Protection N° 180 – Part 2/2
 European Commission (2018) European Guidelines on Diagnostic Reference Levels for Paediatric Imaging. Radiation Protection N° 185
 Struelens L, et al. (2011) The determination of...