Abstract 9434: Cancer Risk Estimation from Cardiac Catheterization in Children with Heart Disease

Abstract

Background: Radiation exposure is a concern in children because of their high radiosensitivity, small body size, and cancer risk. We evaluated the effective dose (ED) of radiation from cardiac catheterization to estimate the lifetime attributable risk (LAR) of cancer. Methods: Organ specific radiation doses were measured from conventional angiographic projections using dosimeters placed in 2 anthropomorphic phantoms representing 1 and 5 years of age. We used a proprietary radiation dose calculator developed from the phantom data to determine ED using catheterization fluoroscopy and cineangiography times for 3 patient cohorts (age < 5yrs): those post Norwood operation, heart transplant and ASD device closure. Age- and sex-specific LARs of cancer above baseline were estimated using the approach of the Committee on Biological Effects of Ionizing Radiation (BEIR VII). Results: Eligible children undergoing catheterization between July 2005 and August 2011 were included in the analysis. The cohort consisted of 67 subjects post-Norwood (191 catheterizations, median time since Norwood: 161 days), 10 post-transplant (91 catheterizations, median time since transplant: 88 days) and 12 post-ASD closure (median age at catheterization 3.9 years). ED and LAR of cancer attributable to catheterization are presented for a single catheterization and for cumulative exposure in those cohorts that undergo repeat procedures (table). LAR of cancer varied depending on age at exposure, gender and ED and was > 0.15% for 80% of all procedures. Adjusting for ED and age at exposure, the median LAR of cancer was twice as high in females vs. males (p<0.01). Conclusion: Cardiac catheterization can result in radiation exposure that increases LAR of cancer to up to 6% above baseline in select populations. These data highlight the need for limiting radiation dose in females, children with normal life expectancy and children that require repeat catheterizations.