Assessment of the Radiation Effects of Cardiac CT Angiography Using Protein and Genetic Biomarkers.

Abstract Objectives The purpose of this study was to evaluate whether radiation exposure from cardiac computed tomographic angiography (CTA) is associated with deoxyribonucleic acid (DNA) damage and whether damage leads to programmed cell death and activation of genes involved in apoptosis and DNA repair. Background Exposure to radiation from medical imaging has become a public health concern, but whether it causes significant cell damage remains unclear. Methods We conducted a prospective cohort study in 67 patients undergoing cardiac CTA between January 2012 and December 2013 in 2 U.S. medical centers. Median blood radiation exposure was estimated using phantom dosimetry. Biomarkers of DNA damage and apoptosis were measured by flow cytometry, whole genome sequencing, and single cell polymerase chain reaction. Results The median dose length product was 1,535.3 mGy·cm (969.7 to 2,674.0 mGy·cm). The median radiation dose to the blood was 29.8 mSv (18.8 to 48.8 mSv). Median DNA damage increased 3.39% (1.29% to 8.04%, p  DDB2 (1.9-fold [IQR: 1.5- to 3.0-fold], p  XRCC4 (3.0-fold [IQR: 1.1- to 5.4-fold], p = 0.005), and BAX (1.6-fold [IQR: 0.9- to 2.6-fold], p  Conclusions Patients exposed to >7.5 mSv of radiation from cardiac CTA had evidence of DNA damage, which was associated with programmed cell death and activation of genes involved in apoptosis and DNA repair.