Establishing diagnostic reference levels for pediatric fluoroscopic examinations in a tertiary hospital

Background: Diagnostic reference levels (DRLs) identify unusually high patient radiation exposures and are required for dose optimisation. DRLs for pediatric fluoroscopic examinations are not widely determined in Australia. Objective: Our objectives were to establish DRLs for pediatric fluoroscopic examinations in a South Australian tertiary hospital and compare these to previously published data and to explore relationships between patient dose area product (DAP), age and fluoroscopy times. Materials and methods: Dose data from 365 pediatric patients undergoing 5 fluoroscopic examinations were retrospectively collected for a 3-year period commencing January 2018 to develop local DRLs. Relationships between DAP, age and fluoroscopy time were explored using scatterplots, Spearman’s correlation, and regression analyses. Results: Local DRLs were significantly lower than data published previously, possibly reflecting technological and procedural advancements. Each 1-year increase in patient age was associated with a 0.77 μGy·m ² increase in DAP for barium meal and follow-through studies (95% confidence interval [CI]=0.055, 1.48) (P=0.04), and a 1.37 μGy·m ² increase in DAP for barium swallow studies (95% CI=0.61, 2.12) (P<0.001). A low correlation was demonstrated between DAP and fluoroscopy time for micturating cystourethrography studies (r=0.35, 95% CI=0.15, 0.51, P<0.001) and barium meal and follow-through studies (r=0.37, 95% CI= −0.011, 0.65, P=0.05). Age and fluoroscopy time were not significantly related. Conclusion: This study provides updated Australian pediatric fluoroscopic DRLs, with the intention of promoting a national database for benchmarking pediatric doses. The local DRLs can be used for dose comparisons and optimisation between facilities.