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Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures

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Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures United States Interagency Working Group EPA-402-R-10003 Environmental Protection on Medical Radiation November 2014 Agency Federal Guidance Report No. 14 EPA-402-R-10003 FEDERAL GUIDANCE REPORT NO. 14 Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures November 2014 Interagency Working Group on Medical Radiation U.S. Environmental Protection Agency Washington, D.C. 20460 Dedication Doreen G. Hill, MPH, PhD, was a long-term member of the ISCORS Medical Workgroup. Sadly, she passed away before she could see her work on Federal Guidance Report No. 14 completed. She represented the Department of Labor's Occupational Safety and Health Administration on the workgroup in an admirable fashion. Doreen brought to the workgroup a high degree of professionalism, a great interest in x-ray safety, a strong work ethic, and a focus on ensuring that we remained sensitive to OSHA regulations and policies. She was our editor, a self-imposed and thankless task, and enforced a clear writing style. She transformed our jargon and incomprehensible run-on sentences into language that conveyed meaning in a straightforward way. Whenever she was unavailable during a web conference, someone else would attempt to fulfill her role, albeit with nowhere near her style and grace, saying they were "channeling Doreen." After her passing, we continued to use the phrase and its intent during our meetings. Doreen brought with her a sense of humor that permeated our meetings. She often said she never wanted to miss a workgroup meeting because they were the most fun, entertaining, and enlightening meetings she had ever attended. It was she who made it so. We miss you, Doreen, and hope that our channeling of your spirit has kept the document's quality high and its readability good. i FOREWORD The authority of the Federal Radiation Council to provide radiation protection guidance to federal agencies was transferred to the Environmental Protection Agency (EPA) on December 2, 1970, by Reorganization Plan No. 3. Under this authority, Federal Guidance Report No. 14 provides federal facilities that use diagnostic and interventional x-ray equipment with recommendations for keeping patient doses as low as reasonably achievable without compromising the quality of patient care. Federal Guidance Report No. 14 is an update to the 1976 x-ray guidance in Federal Guidance Report No. 9. This guidance takes into account that in recent years there has been a significant increase in the use of digital imaging technology and high dose procedures, such as computed tomography (CT). Also, there have been many reports of unnecessarily high doses being given to children undergoing CT exams. The guidance in this document was created by an Interagency Steering Committee on Radiation Standards Work Group, which included medical and radiation protection professionals from the EPA, the Department of Health and Human Services, the Department of Veterans Affairs, the Department of Defense (Departments of the Army, Navy, and Air Force), the Occupational Safety and Health Administration and the Commonwealth of Pennsylvania. The interagency collaborative effort highlights the importance of this guidance for federal healthcare facilities. Federal Guidance Report No. 14 is being issued to all federal facilities that perform diagnostic or interventional x-ray procedures. Private healthcare facilities are encouraged to consider adopting any or all of the guidance and its recommendations as they consider appropriate.While not binding on any agency or facility, incorporating the best practices defined in this guidance will improve the safety of diagnostic and interventional imaging. ii PREFACE Federal Guidance reports were initiated under the Federal Radiation Council (FRC), which was formed in 1959, through Executive Order 10831. A decade later its functions were transferred to the Administrator of the newly formed U.S. Environmental Protection Agency (EPA) as part of Reorganization Plan No. 3 of 1970 (Nixon 1970). Under these authorities it is the responsibility of the Administrator to “advise the President with respect to radiation matters, directly or indirectly affecting health, including guidance for all federal agencies in the formulation of radiation standards and in the establishment and execution of programs of cooperation with States” (EPA 2012). This document is Federal Guidance Report No. 14 (FGR 14), “Radiation Protection Guidance for Diagnostic and Interventional X-ray Procedures.” It replaces Federal Guidance Report No. 9 (FGR 9), “Radiation Protection Guidance for Diagnostic X-rays,” which was released in October 1976. As with FGR 14, the development of FGR 9 was the result of a growing recognition at the time among medical practitioners, medical physicists, and other scientists that medical uses of ionizing radiation represented a significant and growing source of radiation exposure for the U.S. population. Almost 40 years after its release, it is clear that FGR 9 was a groundbreaking achievement. FGR 9 served as the template for the current document, and the authors of FGR 14 are deeply appreciative of the work of their predecessors. FGR 9 provided constructive guidance on the use of diagnostic film radiography, for which there was an incentive to deliver appropriate radiation doses and avoid retakes resulting from under- or over-exposing the film. This report, Federal Guidance Report No. 14, focuses on the transition to digital imaging. It extends the scope to include computed tomography (CT), interventional fluoroscopy, bone densitometry, and veterinary practice, and updates sections on radiography and dentistry that were covered in FGR 9. In addition, it addresses justification of the examination and optimization of radiation dose, and features an expanded section on occupational exposure. There is no question that medical imaging has provided great improvements in medical care through the use of x-rays for diagnosis. As with much of medical care, x-rays provide great benefit when used properly, but are not without risk. Human exposures to medical radiation were neither controlled by law nor covered by consensus guidance. In 1972, the Federal Radiation Council released a report concluding that “...medical diagnostic radiology accounts for at least 90% of the total man-made radiation dose to which the U.S. population is exposed.” In response, the EPA and the U.S. Department of Health, Education, and Welfare (predecessor of the Department of Health and Human Services (DHHS)) developed and issued FGR 9. The key recommendations in FGR 9 were subsequently approved by President Carter (Carter 1978) and published in the Federal Register on February 1, 1978. The basic approach for reducing exposure from diagnostic uses of x-rays in federal facilities involved three principal considerations: 1) eliminating clinically unproductive examinations, 2) assuring the use of optimal technique when examinations are performed, and 3) requiring appropriate equipment to be used (EPA 1976). iii FGR 9 was the first Federal Guidance Report to provide a framework for developing radiation protection programs for diagnostic uses of x-rays in medicine. It introduced into federal guidance the concepts of: Conducting medical x-ray studies only to obtain diagnostic information, Limiting routine or elective screening examinations to those with demonstrated benefit over risk, Considering possible fetal exposures during examinations of pregnant or potentially pregnant patients, Ensuring diagnostic equipment operators meet or exceed the standards of credentialing organizations, Specifying that standard x-ray examinations should satisfy maximum numerical exposure criteria, and Recommending that each imaging facility have a quality assurance program designed to produce radiographs that satisfy diagnostic requirements with minimal patient exposure. Much of FGR 9 has stood the test of time, but other parts have become obsolete. In particular, the advent of digital x-ray image acquisition has eliminated film blackening as a built-in deterrent to overexposing patients. Digital imaging methodologies have improved medical care by increasing the quality of diagnostic images and significantly decreasing the need for exploratory surgeries. However, in some cases, the use of this newer technology was accompanied by a significant increase in patient radiation dose (Compagnone et al. 2006; Seibert et al. 1996). Some newly introduced technologies, e.g., computed tomography (CT), yielded higher patient doses than the radiographic procedures they replaced. Finally, increased utilization of imaging studies resulted in a greater radiation dose to the population. The U.S. Food and Drug Administration’s (FDA) performance standards for ionizing radiation emitting products address radiography, fluoroscopy, and CT equipment, and are codified in 21 CFR 1020 (FDA 2014g). The FDA revised these performance standards in 2005, in part to address some of the radiation dose issues discussed above. The National Council on Radiation Protection and Measurements (NCRP) reports that medical radiation exposure to the average member of the U.S. population has increased rapidly and continues to do so. Their previous estimate, based on 1970’s and early 1980’s data, was that medical exposure accounted for 0.53 millisievert (mSv) or 53 millirem (mrem) per year, which was 15% of the total annual average (per capita) dose (NCRP 1989a). Based on 2006 data, this estimate was increased to 3 mSv (300 mrem) per year or 48% of
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