Diagnostic reference level curves for paediatric fluoroscopic imaging in the Netherlands

Objectives: Establishing paediatric DRLs is challenging due to sparse data availability. The objective was to assess paediatric fluoroscopic dose levels in Dutch clinical practice, as current diagnostic reference levels (DRLs) need updating following the European Guidelines on DRLs for Paediatric Imaging (PiDRL). Material and methods: Air Kerma-area Product (KAP) values were retrospectively collected from paediatric patients (0–18 years) who underwent fluoroscopic procedures in nine Dutch hospitals between 01-01-2017 and 01-06-2021. The protocols included were: micturating cystourethrography (MCU), upper gastrointestinal (Upper GI) and lower gastrointestinal with contrast enema (Lower GI). In accordance with the PiDRL recommendations for sparse data, the 75th percentiles of the median KAP values per age group from each hospital were fitted using an exponential dose-age curve, resulting in an age-dependent DRL curve. DRL values were compared to Dutch, other European national and European DRLs. Results: A total of 971 examinations were included. For MCU, the proposed DRL curve was lower than the Dutch DRLs. The proposed DRL curve for Upper GI was also lower than the UK DRLs. No DRL curve could be established for Lower GI due to limited data. Conclusions: Paediatric fluoroscopic dose levels in this study are substantially lower than the current Dutch DRLs, indicating the need for new national Dutch DRLs for MCU. This study proposes using a DRL dose-age curve to update Dutch paediatric DRLs. Using the proposed curve method, more DRLs could be established than with the conventional method. The proposed DRL curves might serve as input for updating Dutch paediatric DRLs. Key Points: Question Current Dutch diagnostic reference levels for paediatric fluoroscopy need updating, which is challenging due to sparse data availability. Findings Observed dose levels in this retrospective study indicate a potential decrease in Dutch diagnostic reference levels for paediatric fluoroscopy, using a dose-age curve method. Clinical relevance Updating Dutch paediatric fluoroscopic DRLs using a dose-age curve method allows for the establishment of DRLs in case of sparse data availability. This allows for further optimisation of radiation doses in the paediatric population.