Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography

JAMA. 2007 Jul 18;298(3):317-23. doi: 10.1001/jama.298.3.317.

Abstract

Context: Computed tomography coronary angiography (CTCA) has become a common diagnostic test, yet there are little data on its associated cancer risk. The recent Biological Effects of Ionizing Radiation (BEIR) VII Phase 2 report provides a framework for estimating lifetime attributable risk (LAR) of cancer incidence associated with radiation exposure from a CTCA study, using the most current data available on health effects of radiation.

Objectives: To determine the LAR of cancer incidence associated with radiation exposure from a 64-slice CTCA study and to evaluate the influence of age, sex, and scan protocol on cancer risk.

Design, setting, and patients: Organ doses from 64-slice CTCA to standardized phantom (computational model) male and female patients were estimated using Monte Carlo simulation methods, using standard spiral CT protocols. Age- and sex-specific LARs of individual cancers were estimated using the approach of BEIR VII and summed to obtain whole-body LARs.

Main outcome measures: Whole-body and organ LARs of cancer incidence.

Results: Organ doses ranged from 42 to 91 mSv for the lungs and 50 to 80 mSv for the female breast. Lifetime cancer risk estimates for standard cardiac scans varied from 1 in 143 for a 20-year-old woman to 1 in 3261 for an 80-year-old man. Use of simulated electrocardiographically controlled tube current modulation (ECTCM) decreased these risk estimates to 1 in 219 and 1 in 5017, respectively. Estimated cancer risks using ECTCM for a 60-year-old woman and a 60-year-old man were 1 in 715 and 1 in 1911, respectively. A combined scan of the heart and aorta had higher LARs, up to 1 in 114 for a 20-year-old woman. The highest organ LARs were for lung cancer and, in younger women, breast cancer.

Conclusions: These estimates derived from our simulation models suggest that use of 64-slice CTCA is associated with a nonnegligible LAR of cancer. This risk varies markedly and is considerably greater for women, younger patients, and for combined cardiac and aortic scans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Coronary Angiography / adverse effects*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Theoretical
  • Monte Carlo Method
  • Neoplasms, Radiation-Induced / epidemiology*
  • Phantoms, Imaging
  • Radiometry
  • Risk
  • Tomography, Spiral Computed / adverse effects*