Establishing typical dose values in fluoroscopy-guided paediatric central venous catheter placement procedures in a large university hospital

Purpose: Establishing DRLs is internationally recommended for dose optimization, particularly in paediatric procedures. The first step in defining local or national DRLs is determining typical dose values (TVD). This study presents the first Brazilian evaluation of TVD for fluoroscopy-guided central venous catheter (CVC FGI) placement in paediatric patients. Methods: A retrospective analysis was conducted at a large university hospital (2017–2024). Procedures were stratified by age and weight according to ICRP 135 guidelines. Six mobile surgical C-arm units were included: four with image intensifiers and two with flat-panel detectors. Dose indicators included kerma-area product (Pka), cumulative air kerma, and fluoroscopy time. Procedures were stratified by age and weight and the TVD was calculated as the median (second quartile, Q2) of the Pka according to ICRP 135. Associations between Pka and weight or age were assessed using Spearman correlation. Results: Data from 816 patients stratified by weight and 832 by age were analysed. The TVDs corresponding to Q2(Pka) (Gy cm²) by weight (kg) were: <5 (0.044), 5<15 (0.080), 15<30 (0.143), 30<50 (0.189), and 50<80 (0.370). By age in years (Gy cm²): <1 (0.067), 1<5 (0.088), 5<10 (0.170), 10 < 15 (0.312), and ≥15 (0.279). Statistically significant but weak correlations were found between Pka and weight (ρ=0.29, p<0.001) and between Pka and age (ρ=0.27, p<0.001). Weight was the main predictor, though incomplete. Conclusion: TVD for FGI procedures, especially with surgical C-arms, is an important quality indicator. This advances DRL implementation for dose optimization and safety in paediatric radiology.