Health Risks of Ionizing Radiation
Authors: Charles E. Chambers
Journal: Circulation (2017)

HomeCirculationVol. 136, No. 25Health Risks of Ionizing Radiation Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBHealth Risks of Ionizing RadiationDr Roentgen Today Charles E. Chambers, MD Charles E. ChambersCharles E. Chambers Penn State Hershey Medical Center, PA. Originally published19 Dec 2017https://doi.org/10.1161/CIRCULATIONAHA.117.031673Circulation. 2017;136:2417–2419Articles, see p 2406 and p 2516Interventional cardiology is dependent on ionizing radiation. We, as operators, are charged with assessing the risks and benefits of exposure knowing that our patients, staff, and we are reliant on this century-old potentially dangerous imaging modality. Dismissed from high school, enrolled in a Poly-Tech Institute, and ultimately receiving a PhD from the University of Zurich, Wilhelm Conrad Roentgen won the first Nobel Prize in Physics in 1901 for his discovery of the x-ray. On the evening of November 8, 1895, while experimenting with high voltages generated in a partially evacuated glass tube, Dr Roentgen noticed a shimmering barium platino-cyanide screen across the room. Subsequently termed x-rays because of the uncertain nature of his findings, he published this discovery in December 1895 at the age of 50. Over the past century, while benefiting from this discovery, we continue to identify the multiple hazards of Roentgen's x-rays in both patients and operators.In this issue of Circulation, 2 studies provide further evidence of the potential professional hazards from operator exposure to radiation. Modarai and his colleagues1 studied blood samples from operators performing various types of catheter-based endovascular aortic repairs. Specific biomarkers for DNA damage/repair (γ-H2AX) and DNA damage response (phosphorylated ataxia telangiectasia mutated) were measured in circulating lymphocytes. These markers were elevated immediately after radiation exposure and returned to normal by 24 hours, reflecting DNA damage and repair after exposure. Additional radiation protection to the lower extremities mitigated this damage; no DNA damage was detectable in the control group of operators who performed open repair without fluoroscopic imaging.In a separate study, Andreassi and his group2 studied genetic markers in blood samples obtained from 132 interventional cardiologists. Plasma levels of microRNA (mi-RNA) in this group were compared to other clinical cardiologists/healthcare workers not exposed to radiation. mi-RNA was selected because dysregulation in this class of noncoding RNA molecules has been seen in many human diseases. Four different miRNAs were studied. Brain-specific mi-RNA was significantly downregulated in interventional cardiologists compared with controls. Because dysregulated miRNA is seen in certain forms of epilepsy, Alzheimer's disease, and brain cancers, this supports concerns for potential brain malignancies or long-lasting cognitive impairment. The Modarai et al1 and Andreassi et al2 studies had similar limitations. They each lacked specific operator dosimeter correlation to the genetic alterations, and neither study correlated adverse events to these genetic alterations. However, the concerns for the lifetime effects of high-dose exposure to ionizing radiation from fluoroscopic-guided interventions are again highlighted and must be addressed.X-rays are essential to medicine for both diagnosis and therapy. Although this has contributed to significant advances, it has not come without risks. This risk includes a 3-fold increase in patient medical radiation exposure since 1982, with the medical radiation exposure to the US population now exceeding background exposure.3 Although some potential risks are known, the challenges to quantitate these risks are ongoing. Tissue injury will occur with high-dose exposure in patients, classified as deterministic effects. Specific posterior subcapsular cataract injury to the eye is seen as a threshold dose-dependent adverse event from ionizing radiation to operators and staff.4 Stochastic injury, the focus of the studies in this issue of Circulation, is the linear nonthreshold probability of genetic alteration and represents the potential cancer risk for patients, staff, and operators. Although left-sided brain tumors have been identified in interventional cardiologists, a recent publication from the National Cancer Institute comparing mortality between physicians performing fluoroscopy-guided interventions and physicians not performing fluoroscopy-guided interventions revealed no difference in mortality.5 Vascular injury has been recognized in oncology patients undergoing high-dose radiation therapy, and the Life Span study of Japanese atomic bomb survivors demonstrated an increase in myocardial infarctions.6 Endothelial damage in catheterization (cath) laboratory workers was associated with increased subclinical carotid intimamedia thickness suggestive of accelerated vascular injury,7 although no clinical outcomes data are available.Efforts are ongoing to raise radiation awareness. In 2010, the US Food and Drug Administration challenged the industry to focus on dose reduction, recognizing that protecting the patient benefits all cath laboratory personnel.8 Equipment manufacturers responded with imaging modification and best practice protocols. Organizations such as the National Council on Radiation Protection and Measures have published recommendations in 2011 on dose management in fluoroscopic imaging.9 Professional societies have responded with emphasizing radiation safety in the context of quality improvement.10 Cath laboratory dose assessment has moved beyond fluoroscopy time, proved ineffective as a dose parameter, and now uses Total Air Kerma at the Interventional Reference Point in Gy and Air Kerma Area Product (also referred to as Dose Area Product) in Gy cm2. For the first time, radiation received a Class I recommendation in the 2011 American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions guidelines.11 The guidelines identify the need for the cath laboratory report to include all these dose-related parameters and for the cath laboratory quality program to include a process for follow-up of all high-dose patient exposures.Although invasive/interventional cardiology is appropriately focused on quality care/patient outcomes, the risks to the profession must also be addressed. Enthusiastic, talented individuals considering interventional cardiology often have a limited understanding of the potential long-term consequences, with women underrepresented because of these concerns.12 The Multi-Specialty Occupational Health Group, comprised of professional societies whose members perform invasive procedures, identified the health concerns related to a career working with ionizing radiation along with the necessary recommendations to address these concerns.13 In 2015, the Multi-Specialty Occupational Health Group survey reidentified significant health concerns in cath laboratory workers, which differ from other disciplines.14Through these efforts, the importance of protecting cath laboratory workers is being recognized.Risk awareness leads to an emphasis on risk reduction. Modarai's1 identification of genetic alteration from radiation exposure was coupled with the potential benefit of additional leg shieling to reduce this injury. Best practices in the laboratory are effective in dose reduction.15 This requires a culture of radiation awareness integrating radiation safety into the mandated cath laboratory quality program.16 The traditional mantra of radiation safety—time, distance shielding—emphasizes procedural best practices. Patient assessment informed consent before procedures and high-dose patient follow-up after procedures are both recognized as integral components to radiation dose management.10 As the complexity of our interventional procedures increases, radiation awareness in the cath laboratory is essential now more than ever. Chronic total occlusion and left main/multivessel percutaneous coronary interventions, as well as challenging structural heart procedures, are now frequently performed in the cath laboratory. This requires all operators, both cardiologists and surgeons, to receive initial training in radiation safety, with annual updates, as well as be instructed in the proper use of the fluoroscopic equipment.9 Equipment manufacturers, medical physicists, hospital administration, governing bodies, and the medical providers must work together to create a safe environment for all in the cardiac cath laboratory. Without this effort, unnecessary patient exposure and lost manpower from unnecessary and preventable disabilities will continue.So, can we postulate what Dr Roentgen's thoughts would be today? I would expect that he would read the articles in this issue of Circulation and be disappointed that after ≈120 years, a more complete understanding of risk with concentrated efforts for risk reduction is not in place. This pertains to patients, staff, and operators. He would likely question why all physicians do not consistently track their individual procedure and lifetime exposure. He would ask why patient radiation dose is not measured by all, tracked for short-term repetitive procedures, and followed up for all exposed to high doses. Knowing the potential risks, he would insist on detailed training with updates for all involved with ionizing radiation and that all equipment manufactures work in unison for the greater good-maximizing dose reduction to the patient benefiting staff and the interventionalists. When this Nobel laureate knocked on an administrator's door, he would demand that all efforts be taken to protect these priceless commodities—patients, our staff, and operators—recognizing cost must be amortized for a lifetime and not a single fiscal year. Finally, having seen his colleagues suffer from the effects of working with ionizing radiation, Dr Roentgen, I believe, would strongly support and question why we have not already created a national/international reporting system for physicians and staff to track cancer, orthopedic injuries, and other concerns that have arisen from a career performing invasive procedures. Yes, radiation is Dr Roentgen's discovery, but it is both our benefit and our risk. It is essential that all parties participate to create the safest possible cardiac cath laboratory environment for patients, staff, and physicians working with the challenges of the 1901 Nobel-recognized ionizing radiation.DisclosuresNone.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.Circulation is available at http://circ.ahajournals.org.Correspondence to: Charles E. Chambers, MD, Heart and Vascular Institute, Penn State Hershey Medical Center, 500 University Drive, MCHO47, Hershey, PA 17033. E-mail [email protected]References1. El-Sayed T, Patel AS, Cho JS, Kelly JA, Ludwinski FE, Saha P, Lyons OT, Smith A, Modarai B. Radiation-induced DNA damage in operators performing endovascular aortic repair.Circulation. 2017; 136:2406–2416. doi: 10.1161/CIRCULATIONAHA.117.029550.Google Scholar2. Borghini A, Vecoli C, Mercuri A, Carpeggiani C, Piccaluga E, Guagliumi G, Picano E, Andreassi MG. Low-dose exposure to ionizing radiation deregulates the brain-specific microRNA-134 in interventional cardiologists.Circulation. 2017; 136:2516–2518. doi: 10.1161/CIRCULATIONAHA.117.031251.Google Scholar3. National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States (NCRP Report No 160). Bethesda, MD: National Council on Radiation Protection and Measurements;2006. http://ncrponline.org/publications/reports/ncrp-report-160–2/. Google Scholar4. Karatasakis A, Brilakis HS, Danek BA, Karacsonyi J, Martinez-Parachini JR, Nguyen-Trong PJ, Alame AJ, Roesle MK, Rangan BV, Rosenfeld K, Mehran R, Mahmud E, Chambers CE, Banerjee S, Brilakis ES. Radiation-associated lens changes in the cardiac catheterization laboratory: results from the IC-CATARACT (CATaracts Attributed to RAdiation in the CaTh Lab) study [published online ahead of print July 14, 2017].Catheter Cardiovasc Interv. doi: 10.1002/ccd.27173. http://onlinelibrary.wiley.com/doi/10.1002/ccd.27173/full.Google Scholar5. Linet MS, Kitahara CM, Ntowe E, Kleinerman RA, Gilbert ES, Naito N, Lipner RS, Miller DL, Berrington de Gonzalez A; Multi-Specialty Occupational Health Group. Mortality in U.S. physicians likely to perform fluoroscopy-guided interventional procedures compared with psychiatrists, 1979 to 2008.Radiology. 2017; 284:482–494. doi: 10.1148/radiol.2017161306.CrossrefMedlineGoogle Scholar6. Schultz-Hector S, Trott KR. Radiation-induced cardiovascular diseases: is the epidemiologic evidence compatible with the radiobiologic data?Int J Radiat Oncol Biol Phys. 2007; 67:10–18. doi: 10.1016/j.ijrobp.2006.08.071.CrossrefMedlineGoogle Scholar7. Andreassi MG, Piccaluga E, Gargani L, Sabatino L, Borghini A, Faita F, Bruno RM, Padovani R, Guagliumi G, Picano E. Subclinical carotid atherosclerosis and early vascular aging from long-term low-dose ionizing radiation exposure: a genetic, telomere, and vascular ultrasound study in cardiac catheterization laboratory staff.JACC Cardiovasc Interv. 2015; 8:616–627. doi: 10.1016/j.jcin.2014.12.233.CrossrefMedlineGoogle Scholar8. FDA Center for Devices and Radiologic Health. White paper: initiative to reduce radiation exposure from medical imaging.February 2010. https://www.fda.gov/radiation-emittingproducts/radiationsafety/radiationdosereduction/ucm199994.htm.Google Scholar9. Balter S, Schuler BA, Miller DL, Brinker JA, Chambers CE, Layton KF, Marx MV, McCollough CH, Strauss KJ, Wagner LK. Radiation dose management for fluoroscopically-guided interventional medical procedures.National Council on Radiation Protection and Measures, NCRP Report No. 168. 2011. https://www.ncrppublications.org/Reports/168.Google Scholar10. Chambers CE, Fetterly K, Holzer R, Lin PJP, Blankenship JC, Balter S, Laskey WK. Radiation safety program for the cardiac catheterization laboratory.Cath and Card Interv. 2011; 77:510–514. doi:10.1002/ccd.22867.MedlineGoogle Scholar11. Levine GN, Bates ER, Blankenship JC, Bailey SR, Bittl JA, Cercek B, Chambers CE, Ellis SG, Guyton RA, Hollenberg SM, Khot UN, Lange RA, Mauri L, Mehran R, Moussa ID, Mukherjee D, Nallamothu BK, Ting HH. 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions.Circulation. 2011; 124:e574–e651. doi: 10.1161/CIR.0b013e31823ba622.LinkGoogle Scholar12. Chambers CE. Occupational health risks in the interventional cardiology: expected inherent risk or preventable personal liability?JACC Cardiovasc Interv. 2015; 8:628–630. doi: 10.1016/j.jcin.2015.01.015.CrossrefMedlineGoogle Scholar13. Klein LW, Miller DL, Balter S, Laskey W, Haines D, Norbash A, Mauro MA, Goldstein JA; Joint Inter-Society Task Force on Occupational Hazards in the Interventional Laboratory. Occupational health hazards in the interventional laboratory: time for a safer environment.Catheter Cardiovasc Interv. 2009; 73:432–438. doi: 10.1002/ccd.21801.CrossrefMedlineGoogle Scholar14. Klein LW, Tra Y, Garratt KN, Powell W, Lopez-Cruz G, Chambers C, Goldstein JA; Society for Cardiovascular Angiography and Interventions. Occupational health hazards of interventional cardiologists in the current decade: results of the 2014 SCAI membership survey.Catheter Cardiovasc Interv. 2015; 86:913–924. doi: 10.1002/ccd.25927.CrossrefMedlineGoogle Scholar15. Fetterly KA, Mathew V, Lennon R, Bell MR, Holmes DR, Rihal CS. Radiation dose reduction in the invasive cardiovascular laboratory: implementing a culture and philosophy of radiation safety.JACC Cardiovasc Interv. 2012; 5:866–873. doi: 10.1016/j.jcin.2012.05.003.CrossrefMedlineGoogle Scholar16. Christopoulos G, Makke L, Christakopoulos G, Kotsia A, Rangan BV, Roesle M, Haagen D, Kumbhani DJ, Chambers CE, Kapadia S, Mahmud E, Banerjee S, Brilakis ES. Optimizing radiation safety in the cardiac catheterization laboratory: a practical approach.Catheter Cardiovasc Interv. 2016; 87:291–301. doi: 10.1002/ccd.25959.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Herbst C, Emerich K, Mayr M, Rudisch A, Kremser C, Talasz H and Kofler M (2023) Time-Synchronized MRI-Assessment of Respiratory Apparatus Subsystems—A Feasibility Study, Journal of Voice, 10.1016/j.jvoice.2022.11.006, Online publication date: 1-Jan-2023. Mai F, Zhang Q, Wang R, Meng L, Zhang Y, Li J, Liu P, Li Y and Zhou Y (2022) Polymer Fibers Highly Filled with Styrene Maleic Anhydride-Modified PbWO 4 for Improved Wear Comfort of γ-ray-Shielding Articles , ACS Applied Polymer Materials, 10.1021/acsapm.2c00807, 4:9, (6394-6402), Online publication date: 9-Sep-2022. Sharkey A, Gambhir P, Saraskani S, Walker R, Hajilou A, Bassett P, Sandhu N, Croasdale P, Honey I, Diamantopoulos A and Goh V (2021) Occupational radiation exposure in doctors: an analysis of exposure rates over 25 years, The British Journal of Radiology, 10.1259/bjr.20210602, 94:1127, Online publication date: 1-Nov-2021. December 19, 2017Vol 136, Issue 25 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/CIRCULATIONAHA.117.031673PMID: 29255122 Originally publishedDecember 19, 2017 Keywordsoccupational healthcardiac catheterizationradiationEditorialsPDF download Advertisement