Organ-level radiation dose estimations from cardiac catheterizations in neonates with tetralogy of Fallot.

PURPOSE

Children with congenital heart disease (CHD) undergo procedures requiring ionizing radiation (IR). Estimation of organ-level radiation exposure is difficult due to differences in patient size and other technical parameters. Here, we utilized a dosimetry tool to estimate organ-level radiation doses from a sample of cardiac catheterizations performed in a neonatal cohort with tetralogy of Fallot (TOF), the most common form of cyanotic CHD, requiring early intervention.

METHODS AND MATERIALS

An organ dose calculation program, the National Cancer Institute dosimetry system for Radiography and Fluoroscopy (NCIRF), was utilized to estimate absolute organ radiation doses (mGy) and effective dose (mSv). Beam spectra, exposure field configuration, distance from and direction of the X-ray beam, isocenter location, and dose-area-product (DAP, Gy-cm2) for each patient were used as input parameters for organ dose calculations collected from a multi-center clinical research collaborative.

RESULTS

Median posterior-to-anterior (PA) and lateral DAP from 44 cardiac catheterizations was 74.8 and 38.0 Gy-cm, respectively. Median effective dose was 1.35 mSv and 0.74 for PA and lateral projections, respectively. Organ doses were highest in the PA view for spinal cord (4.71 mGy), adrenal glands (4.26 mGy), and lung (3.90 mGy). Organ dose was highest for breast in the lateral view (2.8 mGy).

CONCLUSIONS

This is the first description of organ doses from cardiac catheterizations in a neonatal TOF population and will help to define the potential contribution of early childhood IR exposure to long-term radiation-related complications. As other neonates without TOF undergo similar interventions, these estimations may identify other CHD populations at risk for higher IR exposure, assist in quality improvement measures to reduce IR exposure in current clinical practice, and influence clinical pathway decision-making in this vulnerable population.