Local DRL estimation and effective dose calculation in paediatric interventional cardiology using measurements and Monte Carlo simulations

Background

Paediatric patients with congenital heart disease benefit greatly from X-ray diagnostic and interventional procedures. However, multiple procedures lead to prolonged exposure to ionizing radiation (IR), raising concerns for secondary long-term health issues.

Purpose

This study aimed to establish local dose reference levels (LDRLs) for a National Reference Center for Congenital Cardiopathies (NRCCC) in Portugal. Additionally, it estimated effective and organ doses in paediatric patients undergoing coronary angiographies (CAs) using measurements and Monte Carlo simulations.

Methods

LDRLs were determined through statistical analysis of patient registry data from 120 patients recorded between 2022 and 2023. For effective dose estimation, personal dose equivalent values Hp(10) were measured with an anthropomorphic phantom (CIRS ATOM 705) and Raysafe dosimeters, used to validate Monte Carlo (MC) simulations, which were then employed with rescaled paediatric voxel phantoms (GsF Baby and Child), to estimate effective doses and dose conversion coefficients (DCCs) for representative patient anatomies across different age and weight groups.

Results

LDRLs for coronary angiographies at the NRCCC showed significant dose variability, indicating dose optimization opportunities. Monte Carlo simulations allowed for organ dose and effective dose calculations. Dose Conversion Coefficients were 1.107, 0.882, 0.719, and 0.524 mSv/Gy·cm² for newborn, 1 year-old, 5 year-old and 10 year-old groups respectively. A strong linear correlation between effective dose and air-kerma area product (KAP) was observed.

Conclusions

The study highlights the strong correlation between effective dose and KAP, offering a practical framework for estimating patient doses and enhancing radiation safety protocols in clinical practice.