JACC Cardiovasc Imaging. 2015 Aug;8(8):873-84. doi: 10.1016/j.jcmg.2015.04.016. Epub 2015 Jul 22.

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

Nguyen PK¹, Lee WH², Li YF³, Hong WX², Hu S², Chan C⁴, Liang G⁵, Nguyen I⁵, Ong SG², Churko J², Wang J⁶, Altman RB³, Fleischmann D⁷, Wu JC⁸.

Author information

1: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California; Veterans Administration Palo Alto, Palo Alto, California; Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California. Electronic address: pknguyen@stanford.edu.
2: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California; Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California.
3: Department of Genetics, Stanford University School of Medicine, Stanford, California.
4: Department of Surgery, Stanford University School of Medicine, Stanford, California.
5: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California.
6: Environmental Health and Safety, Stanford University School of Medicine, Stanford, California.
7: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California; Department of Radiology, Stanford University School of Medicine, Stanford, California.
8: Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California; Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California; Department of Radiology, Stanford University School of Medicine, Stanford, California. Electronic address: joewu@stanford.edu.

Erratum in

JACC Cardiovasc Imaging. 2015 Nov;8(11):1350.

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 < 0.0001) and median apoptosis increased 3.1-fold (interquartile range [IQR]: 1.4- to 5.1-fold, p < 0.0001) post-radiation. Whole genome sequencing revealed changes in the expression of 39 transcription factors involved in the regulation of apoptosis, cell cycle, and DNA repair. Genes involved in mediating apoptosis and DNA repair were significantly changed post-radiation, including DDB2 (1.9-fold [IQR: 1.5- to 3.0-fold], p < 0.001), 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 < 0.001). Exposure to radiation was associated with DNA damage (odds ratio [OR]: 1.8 [1.2 to 2.6], p = 0.003). DNA damage was associated with apoptosis (OR: 1.9 [1.2 to 5.1], p < 0.0001) and gene activation (OR: 2.8 [1.2 to 6.2], p = 0.002).

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.