Evaluation of levels of exposure of adult patients from common radiographic examinations in the Russian Federation in 2009–2014

Abstract

Diagnostic reference levels are the main and the most effective tools of optimization of the radiation protection of patients from medical exposure. Diagnostic reference levels should be established based on the results of dedicated dose surveys, allowing evaluating typical patient dose distributions in a selected dose quantity for the selected X-ray examinations. The aim of the current study was to assess the distributions of typical effective doses in representative Russian regions. Materials and methods: Typical patient effective doses for the 13 most common radiographic X-ray examinations were collected in 203 X-ray rooms in 101 hospitals in six regions of Russian Federation in 2009–2014. A differentiated approach was used for the estimation of the typical effective doses depending on the image acquisition technology. Effective doses were estimated using «EDEREX» (Russia) computational software. Results and discussion: Results of the dose data analysis indicate the lack of significant differences between the distributions of the typical effective doses between the selected regions, allowing merging the regional samples and further evaluating the pooled (joint) sample. A significant ratio of maximum to minimum (up to two orders of magnitude) due to a presence of X-ray units with abnormally high and low typical effective doses was observed for all 13 selected X-ray examinations. Abnormally high typical effective doses can be explained by performing the examinations using high values of tube current-time product (150–600 mAs) on a maximum field size (up 40×40 cm). Removal of the typical effective doses below 5%-percentile and above 95%-percentile of typical effective dose distributions for all examinations would result in a reduction of a mean effective dose by up to 30% and reduction of a 75%-percentile of the distributions by up to 15%. No significant differences between the distributions of TED for analogue and digital X-ray units were observed for the pooled sample for selected examinations except for the examination of the chest in posterior-anterior projection. Conclusions: These results should be considered in the process of establishing and implementing DRLs as well as in the cost-benefit analysis of the optimization in radiography.