Estimation of radiation dose to the paediatric cardiac patient in a paediatric cardiac catheterisation laboratory: concerns and ways ahead.

PURPOSE: Children with CHDs are exposed to ionising radiation during diagnostic and interventional cardiac catheterisation procedures. Data regarding radiation doses a child is exposed to during these procedures are scarce. We aimed to investigate the radiation dose and other related parameters for paediatric cardiac catheterisation and propose these as local reference levels.

METHODS AND MATERIALS: We collected radiation exposure data for all diagnostic and interventional cardiac catheterisation cases (excluding electrophysiology procedures) utilising fluoroscopy at "Anonymized for review" between January 1, 2021 and November 30, 2021. Direct measures of radiation usage, i.e. fluoroscopy time, dose-area product value, and air kerma, were reported for each case by the INNOVA 2100 manufactured by Wipro GE Healthcare. The absorbed radiation dose was measured using a Bhabha Atomic Research Centre dosimeter, which was placed directly on the patients' chests. Differences in measures of radiation exposure across procedural and interventional types were tested using the normality of continuous data by Kolmogorov-Smirnov test. Spearman's correlation coefficient was calculated when the data violated normality.

RESULTS

The overall median dose-area product, fluoroscopy time, air kerma, and absorbed dose measured using a Bhabha Atomic Research Centre dosimeter were 300 mg.m2, 10.5 mins, 37 mGy, and 2.4 mSv, respectively. We have further categorised the median exposure parameters into 5 age groups and propose them as local dose reference levels. There was a strong correlation between fluoroscopy time with the absorbed radiation dose (Rho = 0.942). Fluoroscopy time showed fair correlation with air kerma (Rho = 0.65) and dose-area product (Rho = 0.59). Absorbed radiation dose showed fair correlation with dose-area product ( Rho = 0.56).

CONCLUSION

Fluoroscopy time alone is not a sufficient metric to monitor radiation exposure. Even when fluoroscopy times were comparable, air kerma and dose-area product levels were quite different. Therefore, the local dose reference levels proposed can be used as a benchmark for future studies aimed at process optimisation and further reducing the radiation exposure in paediatric patients.