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Radiation Exposure Update
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Medical Imaging Saves and Extends Lives

An article in the New England Journal of Medicine (NEJM) published in August of 20091 has raised concerns about the radiation exposure a patient receives during a computer tomography (MDCT) medical imaging exam and its risk of causing cancer long term. This article and other sensational claims in the news are misleading. There is concern that some patients will avoid receiving medical imaging care—services that may save and extend lives—because of these reports.

The following information from the American College of Radiology (ACR) is provided to give you an accurate understanding of this issue.

Introduction
Medical imaging exams and image- guided procedures are increasingly replacing more invasive and often more costly techniques while saving and extending lives every day. The American College of Radiology, in conjunction with other imaging stakeholders like Washington Imaging Services, has long addressed issues regarding radiation dose from medical imaging exams and inappropriate utilization of these scans. Patients and referring physicians are urged not to delay or avoid seeking needed imaging care because of radiation concerns raised in the NEJM study.

Fazel NEJM Study
In “Exposure to Low‐Dose Ionizing Radiation from Medical Imaging Procedures,” Reza Fazel, M.D., M.Sc., and colleagues reported that imaging procedures are a key source of ionizing radiation exposure in the U.S. and that repeat exams can result in high cumulative doses of radiation. They also recognize that, “An important reason for the growing use of such procedures stems from their ability to radically improve patient care.” The ACR thanks the study authors for addressing these issues.

However, it should be noted that the patients outlined in the study who experienced the higher doses of radiation (and repeated exams) were cancer patients and others with chronic illnesses. Their conditions necessitated repeat exams to gauge the effectiveness of their treatment and/or help ensure their short term survival. For these patients—who would otherwise be forced to undergo invasive surgeries and, who without the information gleaned from these scans, may have suffered serious health setbacks or even death—the benefits of these exams clearly outweigh the risk of long‐term adverse health effects from radiation.

For most other patients, repeated exams and the high levels of radiation discussed in the study are not realistic. It is important to understand this to provide context and avoid unnecessary fear that may lead to patients foregoing necessary imaging care and placing their health in jeopardy.

The Fazel study also points out that nearly 82 percent of the total administered dose occurred outside of the hospital or outpatient imaging setting. Radiologists perform less than a third of non-hospital or non‐imaging center imaging.2 Most of the scans explored in the study were performed by non-radiologist providers that self‐referred patients to their own imaging equipment. Studies have shown that when providers can refer patients to their own scanners or those in which they have a financial interest, imaging is greatly increased.3,4,5 Many of these providers have little to no imaging or radiation safety training. Knowledge of the correct use of these technologies is not universal.

An Incorrect "Perspective"
More serious and ill‐advised claims are made in “Elements of Danger—The Case of Medical Imaging,” an accompanying “perspective” to the NEJM article that states “With few exceptions, such as mammography, most radiologic imaging tests offer net negative results." There is no evidence to support this claim which is refuted by a recent paper from the National Bureau of Economic Research which directly attributes advanced medical imaging with increased life expectancy.6

In regard to utilization patterns, the perspective states, "Physicians can easily defend their practices because their specialty societies argue that the procedures are 'appropriate' The issue of radiation exposure is unlikely to come up." This is patently false. ACR Appropriateness Criteria (www.acr.org/ac), created more than a decade ago and available to all providers, help physicians prescribe the most appropriate imaging exam for more than 210 clinical conditions and do factor radiation dose into the decision making process. ACR Appropriateness Criteria are used by many private insurers in their coverage process as well as point of entry decision making software in use at Massachusetts General Hospital and elsewhere to help determine the most appropriate exams for patients.

The perspective also negatively categorizes scans by stating that, "Patients incurred costs for procedures of uncertain value..." Negative exams are of value. They preclude further costly and invasive exploratory techniques, rule out disease, provide a baseline to monitor patient health and provide the patient with peace of mind.

Efforts to Reduce Radiation Dose
The radiology community has embraced the ‘ALARA’ or ‘as low as reasonably achievable’ concept that urges providers to use only the amount of radiation necessary to obtain optimal images. Radiologists are working to lower radiation dose and to educate elected officials, government agency staff and referring physicians of the need for further steps toward this goal. The ACR, in an effort to stem the unnecessary growth in radiation dose that Americans receive from imaging, has worked with other radiology organizations to educate all stakeholders in the principles of radiation safety and appropriate utilization of imaging.

For years, the ACR has promoted radiation safety among radiologists, non-radiologists and the public. These efforts include the ACR Practice Guidelines and Technical Standards, facility accreditation programs, government relations programs, the ACR Appropriateness Criteria, continuing medical education offerings and the ACR patient education Web site, www.radiologyinfo.org.

ACR accreditation mandates that the providers reading scans meet basic education and training standards. Additionally, imaging equipment must be surveyed regularly by a medical physicist to ensure that it is functioning properly and the radiation dose is not excessive. Technologists administering the test must also be appropriately certified.

The College also published the ACR White Paper on Radiation Dose in Medicine. This extensive set of 33 recommendations was designed to counteract medical and societal trends that contribute to increased radiation dose as this beneficial technology advances. To date, 27 of the 33 recommendations have been completed or are in progress.

In 2007, the Society for Pediatric Radiology (SPR) initiated the Alliance for Radiation Safety in Pediatric Radiology, which the ACR joined as a founding member. The Alliance is conducting the Image Gently campaign to make providers aware of opportunities to lower the radiation dose used in the imaging of children. The Alliance now encompasses 44 medical organizations from the United States and around the world.

Currently, the Alliance is collaborating with imaging manufacturers to standardize dose assessment and display for children and to improve technologist education, ensuring that CT scanning radiation levels are appropriate for children. In support of this initiative, they have produced “My Child’s Medical Imaging Record” card which can be downloaded from the Image Gently site. It allows parents to record where and when a study was performed as well as the type of radiologic exam. This can help their future medical providers make more informed decisions regarding optimal timing of additional radiologic examinations.

What Patients Can Do
The organizations listed above urge patients and providers to visit the following links for more information regarding radiation exposure from medical imagining exams: www.acr.org/safety, www.radiologyinfo.org/en/safety and www.imagegently.org.

Patients should also keep a record of their x‐ray history and before undergoing a scan, should ask their physician:

Fortunately, the newest CT systems (like the Siemens Sensation in use here at Washington Imaging Services) have an automatic exposure control option that limits the amount of radiation the patient receives based on body size and the area being imaged. This will go a long way in reducing the radiation exposure during a CT exam.

We can also look at replacing CT use, when practical, with other imaging modalities such as ultrasonography and magnetic resonance imaging (MRI). The cost of an MRI is decreasing, making it more competitive with CT—but currently there are not many common imaging scenarios in which MRI can match the speed and resolution of a CT scan.

Washington Imaging Services shares the belief of the American College of Radiology that no medical test, particularly those utilizing ionizing radiation, should be performed unless the medical benefits clearly outweigh any risk associated with the exam. We also support the ‘as low as reasonably achievable’ (ALARA) concept which urges providers to use the minimum level of radiation needed in such exams to achieve the necessary results.

For more information see Medical Imaging and Radiation Exposure.

Editorial content provided by the American College of Radiology

References:

1Reza Fazel, M.D., M.Sc., et. al. Exposure to Low-Dose Ionizing Radiation from Medical Imaging Procedures. NEJM, August 27, 2009.
2Sunshine JH, Bansal S, Evans RG. Radiology Performed by Non‐radiologists in the United States: Who Does What? AJR .1993;61:419‐429.
3Aronovitz LG. Referrals to physician‐owned Imaging Facilities Warrant HCFA’s Scrutiny: General Accounting Office Report to the U.S. House of Representatives. Washington, DC: GAO, 1994:5 Publication GAO/HEHS‐95‐2.
4Hillman BJ, Olson GT, Griffith PE, et al. Physicians’ Utilization and Charges for Outpatient Diagnostic Imaging in a Medicare Population. JAMA.1992;268:2050‐4.
5Gazelle, Scott. “Utilization of Diagnostic Medical Imaging: Comparison of Radiologist Referral Versus Same‐Specialty Referral.” Radiology: Volume 245: Number 2—November 2007.
6Lichtenberg, Frank. The Quality of Medical Care, Behavioral Risk Factors, and Longevity. National Bureau of Economic Research (June 2009).

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