National, local databases of CT dose data needed

Data extracted from RIS and PACS systems are superior to self-reported survey data, calling for the creation of national and local databases that capture CT dose data for the development of diagnostic reference levels (DRLs) and monitoring of population radiation dose, according to a study published in the February issue of the European Journal of Radiology.

While databases of CT scanner radiation doses maintained by RIS and PACS systems are ideal in the management and monitoring of population dose, efficient data extraction remains a challenge. As a result of this reality, self-reported survey methods are currently used for capture of regional and national CT dose information, wrote lead author Rachael E. Moorin, PhD, of the Centre for Population Health Research in Perth, Australia, and colleagues.

The researchers gathered technical data on local CT from a large metropolitan tertiary hospital in Western Australia using data collection methods from RIS and PACS systems and self-survey methods for a range of adult CT scanning examinations. They then calculated radiation dose for both sets of data and the results were evaluated for indexes of inter-rater agreement.

Results indicated that radiation dose calculated using self-report survey data differed systematically and proportionately from the dose that was calculated from PACS/RIS systems. Differences were inconsistent across CT exam types, and the disparity was greater for organ dose than effective dose because of dependence on generic anatomical start and stop limits in comparison with actual data that are available from the PACS/RIS.

“Importantly, the study found the differences were not consistent across CT examination types, indicating the disparity cannot be adjusted using a simple correction factor,” wote Moorin and colleagues. They continued: “This study has confirmed data extracted from RIS/PACS is superior to self-reported survey data and has shown survey data contains both proportional and systematic bias not consistent across CT examinations. We recommend national and local databases that are established to routinely capture aggregated and anonymous CT dose data for the development and monitoring of DRLs and surveillance of population radiation dose.”