Calculating organ and effective doses in paediatric interventional cardiac radiology based on DICOM structured reports – Is detailed examination data critical to dose estimates?


By: Angeliki Karambatsakidou, Artur Omar, Annette Fransson, Gavin Poludniowskiab

Highlights
• Doses calculated using data from radiation dose structured reports (RDSR)

• No differences in average dose, estimated with RDSR- or a simplified method.

• Conversion coefficients presented for organ doses in paediatric heart catheterization.

Abstract
Purpose
To estimate effective dose (E), equivalent organ doses (HT) and associated conversion coefficients (CCE:KAP = E/KAP, CCHT:KAP = HT/KAP; KAP = Kerma-area product) in paediatric cardiac interventions, using detailed exposure data from radiation dose structured reports (RDSR). These “RDSR dose estimations” have been compared with estimations performed using the approach currently implemented in the clinic that is based on a simplified assumptions method (SAM).

Methods
The Monte Carlo system PCXMC, incorporated into a previously developed framework, was used to calculate E and HT for 202 children. The calculations were performed with input values from RDSR, and also using simplified assumptions, including fixed nominal values for the focus-skin distance, collimated beam size, irradiation geometry and patient size (age, weight and height).

Results
Mean HT to critical organs were: 5–25 mSv (lungs), 5–8 mSv (breasts) and 5–22 mSv (heart), with the lower and upper end of the doses associated with the neonatal and 15 years group, respectively. The associated mean CCHT:KAP for the different age groups were: 9.4–1.6 mSv/Gycm2 (lungs), 8.9–0.54 mSv/Gycm2 (breasts) and 9.3–1.4 mSv/Gycm2 (heart).

Conclusions
The extension of the concept of a conversion coefficient for HT is introduced and CCHT:KAP values for paediatric cardiac interventions divided in age groups are presented. [Read more…]

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