Radiation dose and risk of malignancy from cardiovascular imaging
- Thomas C Gerber, MD, PhD, FACC, FAHA
Thomas C Gerber, MD, PhD, FACC, FAHA
- Professor of Medicine and Radiology
- College of Medicine, Mayo Clinic
- Andrew J Einstein, MD, PhD, FACC, FAHA
Andrew J Einstein, MD, PhD, FACC, FAHA
- Herbert Irving Associate Professor of Medicine
- Columbia University Medical Center
- Section Editors
- Donald Cutlip, MD
Donald Cutlip, MD
- Section Editor — Interventional Cardiology
- Professor of Medicine
- Harvard Medical School
- Beth Israel Deaconess Medical Center
- Patricia A Pellikka, MD, FACC, FAHA, FASE
Patricia A Pellikka, MD, FACC, FAHA, FASE
- Section Editor — Noninvasive Cardiac Imaging and Stress Testing
- Professor of Medicine
- Mayo Clinic College of Medicine
The use of diagnostic cardiovascular imaging has increased rapidly over the past decade owing to developments in technology, increased availability, and the perception that imaging can meaningfully affect medical decision making. Studies documenting increasing medical radiation exposure, particularly from cardiovascular imaging, have raised concerns about potential health risks associated with this exposure and have been highly publicized in the professional and lay literature [1,2].
Several of the major imaging modalities for cardiovascular diagnosis and treatment use ionizing radiation. Radionuclide myocardial perfusion imaging in the form of single photon emission computed tomography and positron emission tomography use radionuclides that produce both photon and particulate radiation. Sources of radiograph radiation include cardiovascular computed tomography, which is used for imaging coronary artery plaque and calcification, and radiograph fluoroscopy, which is used to guide established and emerging diagnostic and therapeutic electrophysiologic, coronary, and other cardiovascular procedures.
The potential risks of imaging tests that use ionizing radiation must be weighed against the potential benefits of these tests. This assessment is difficult since the health risks related to radiation exposure at the levels common in cardiovascular imaging are controversial. In addition, limited evidence is available on the impact of these tests on clinical outcomes.
This topic will discuss radiation exposure and potential risks from cardiovascular imaging. Various cardiovascular imaging tests and radiation-related risk of medical imaging studies generally are discussed in detail separately. (See "Radiation-related risks of imaging studies".)
Parameters — Some radiation dosimetry parameters can be measured whereas others are estimates that are modeled using complex assumptions and simulations. Parameters of radiation dosimetry readily derived from physical measurements of radiation exposure (in Coulomb/kg, C/kg) include the accumulated air kerma at a reference point (Ka,r, in mGy) and the kerma-area product (KAP, in cGy × cm2 or related units) in radiography and fluoroscopy (in units of milliGray, mGy), the volume computed tomographic dose index (CTDIvol, in mGy) and the dose-length product (DLP, in mGy x cm) in computed tomography (CT) [3,4]. These parameters are extremely useful to establish so-called "diagnostic reference levels" for quality control and benchmarking among institutions that perform cardiac imaging with ionizing radiation . For example, consistently exceeding the 75th to 80th percentile as established in radiation dose surveys should suggest to an individual institution the need for reevaluation and change of practices. Establishing reference values has been shown to reduce the median dose and interinstitutional dose variability of radiological procedures [6,7]. Parameters of radiation dosimetry are discussed in detail elsewhere. (See "Biology and clinical features of radiation injury in adults".)
- Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med 2007; 357:2277.
- Fazel R, Krumholz HM, Wang Y, et al. Exposure to low-dose ionizing radiation from medical imaging procedures. N Engl J Med 2009; 361:849.
- Morin RL, Gerber TC, McCollough CH. Radiation dose in computed tomography of the heart. Circulation 2003; 107:917.
- Einstein AJ, Moser KW, Thompson RC, et al. Radiation dose to patients from cardiac diagnostic imaging. Circulation 2007; 116:1290.
- American College of Radiology (ACR) practice guideline for diagnostic reference levels in medical x-ray imaging. 2006. http://www.acr.org/SecondaryMainMenuCategories/quality_safety/RadSafety/RadiationSafety/guideline-diagnostic-reference.aspx (Accessed on March 12, 2009).
- Suleiman OH, Conway BJ, Quinn P, et al. Nationwide survey of fluoroscopy: radiation dose and image quality. Radiology 1997; 203:471.
- Van Unnik JG, Broerse JJ, Geleijns J, et al. Survey of CT techniques and absorbed dose in various Dutch hospitals. Br J Radiol 1997; 70:367.
- McCollough CH, Schueler BA. Calculation of effective dose. Med Phys 2000; 27:828.
- Martin CJ. Effective dose: how should it be applied to medical exposures? Br J Radiol 2007; 80:639.
- Gerber TC, Carr JJ, Arai AE, et al. Ionizing radiation in cardiac imaging: a science advisory from the American Heart Association Committee on Cardiac Imaging of the Council on Clinical Cardiology and Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention. Circulation 2009; 119:1056.
- International Atomic Energy Agency (IAEA)'s Smart Card project. http://rpop.iaea.org/RPOP/RPoP/Content/Documents/Whitepapers/smart-card-article.pdf (Accessed on December 07, 2009).
- Mettler FA Jr, Thomadsen BR, Bhargavan M, et al. Medical radiation exposure in the U.S. in 2006: preliminary results. Health Phys 2008; 95:502.
- Schauer DA, Linton OW. NCRP Report No. 160, Ionizing Radiation Exposure of the Population of the United States, medical exposure--are we doing less with more, and is there a role for health physicists? Health Phys 2009; 97:1.
- Chen J, Einstein AJ, Fazel R, et al. Cumulative exposure to ionizing radiation from diagnostic and therapeutic cardiac imaging procedures: a population-based analysis. J Am Coll Cardiol 2010; 56:702.
- Laskey WK, Wondrow M, Holmes DR Jr. Variability in fluoroscopic X-ray exposure in contemporary cardiac catheterization laboratories. J Am Coll Cardiol 2006; 48:1361.
- Cusma JT, Bell MR, Wondrow MA, et al. Real-time measurement of radiation exposure to patients during diagnostic coronary angiography and percutaneous interventional procedures. J Am Coll Cardiol 1999; 33:427.
- Perisinakis K, Damilakis J, Theocharopoulos N, et al. Accurate assessment of patient effective radiation dose and associated detriment risk from radiofrequency catheter ablation procedures. Circulation 2001; 104:58.
- Macle L, Weerasooriya R, Jais P, et al. Radiation exposure during radiofrequency catheter ablation for atrial fibrillation. Pacing Clin Electrophysiol 2003; 26:288.
- Lickfett L, Mahesh M, Vasamreddy C, et al. Radiation exposure during catheter ablation of atrial fibrillation. Circulation 2004; 110:3003.
- Ector J, Dragusin O, Adriaenssens B, et al. Obesity is a major determinant of radiation dose in patients undergoing pulmonary vein isolation for atrial fibrillation. J Am Coll Cardiol 2007; 50:234.
- Smith-Bindman R, Lipson J, Marcus R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med 2009; 169:2078.
- Hausleiter J, Meyer T, Hermann F, et al. Estimated radiation dose associated with cardiac CT angiography. JAMA 2009; 301:500.
- Einstein AJ, Weiner SD, Bernheim A, et al. Multiple testing, cumulative radiation dose, and clinical indications in patients undergoing myocardial perfusion imaging. JAMA 2010; 304:2137.
- Einstein AJ, Pascual TN, Mercuri M, et al. Current worldwide nuclear cardiology practices and radiation exposure: results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS). Eur Heart J 2015; 36:1689.
- Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA 2007; 298:317.
- McCollough CH, Primak AN, Saba O, et al. Dose performance of a 64-channel dual-source CT scanner. Radiology 2007; 243:775.
- Earls JP, Berman EL, Urban BA, et al. Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose. Radiology 2008; 246:742.
- Raff GL, Chinnaiyan KM, Share DA, et al. Radiation dose from cardiac computed tomography before and after implementation of radiation dose-reduction techniques. JAMA 2009; 301:2340.
- Maruyama T, Takada M, Hasuike T, et al. Radiation dose reduction and coronary assessability of prospective electrocardiogram-gated computed tomography coronary angiography: comparison with retrospective electrocardiogram-gated helical scan. J Am Coll Cardiol 2008; 52:1450.
- Pontone G, Andreini D, Bartorelli AL, et al. Diagnostic accuracy of coronary computed tomography angiography: a comparison between prospective and retrospective electrocardiogram triggering. J Am Coll Cardiol 2009; 54:346.
- Rosenthal LS, Mahesh M, Beck TJ, et al. Predictors of fluoroscopy time and estimated radiation exposure during radiofrequency catheter ablation procedures. Am J Cardiol 1998; 82:451.
- Koenig TR, Mettler FA, Wagner LK. Skin injuries from fluoroscopically guided procedures: part 2, review of 73 cases and recommendations for minimizing dose delivered to patient. AJR Am J Roentgenol 2001; 177:13.
- Koenig TR, Wolff D, Mettler FA, Wagner LK. Skin injuries from fluoroscopically guided procedures: part 1, characteristics of radiation injury. AJR Am J Roentgenol 2001; 177:3.
- Einstein AJ. Effects of radiation exposure from cardiac imaging: how good are the data? J Am Coll Cardiol 2012; 59:553.
- Pearce MS, Salotti JA, Little MP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet 2012; 380:499.
- Einstein AJ. Beyond the bombs: cancer risks of low-dose medical radiation. Lancet 2012; 380:455.
- Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ 2013; 346:f2360.
- Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation Board on Radiation Effects Research Division on Earth and Life Studies National Research Council of the National Academies. Health risks from exposure to low levels of ionizing radiation: BEIR VII-Phase 2. National Academies Press; Washington, DC 2006.
- Tubiana M, Feinendegen LE, Yang C, Kaminski JM. The linear no-threshold relationship is inconsistent with radiation biologic and experimental data. Radiology 2009; 251:13.
- National Council on Radiation Protection and Measurements (NCRP). Risk estimates for radiation protection. National Council on Radiation Protection and Measurements (NCRP), Bethesda, MD 1993.
- Berrington de González A, Darby S. Risk of cancer from diagnostic X-rays: estimates for the UK and 14 other countries. Lancet 2004; 363:345.
- Faletra FF, D'Angeli I, Klersy C, et al. Estimates of lifetime attributable risk of cancer after a single radiation exposure from 64-slice computed tomographic coronary angiography. Heart 2010; 96:927.
- Knuuti J, Bengel F, Bax JJ, et al. Risks and benefits of cardiac imaging: an analysis of risks related to imaging for coronary artery disease. Eur Heart J 2014; 35:633.
- Einstein AJ, Berman DS, Min JK, et al. Patient-centered imaging: shared decision making for cardiac imaging procedures with exposure to ionizing radiation. J Am Coll Cardiol 2014; 63:1480.
- Fazel R, Gerber TC, Balter S, et al. Approaches to enhancing radiation safety in cardiovascular imaging: a scientific statement from the American Heart Association. Circulation 2014; 130:1730.
- RADIATION DOSIMETRY
- Radiation doses associated with medical imaging
- - Epidemiology
- - Radiation dose and determinants
- - Multiple testing
- Options for reducing radiation dose
- HEALTH RISKS OF RADIATION EXPOSURE
- Potential carcinogenesis from imaging
- BALANCING RISKS AND BENEFITS
- SUMMARY AND RECOMMENDATIONS