Full article reprinted from "The Gray Sheet"- February 16, 2010
FDA will develop new safety requirements for computed tomography and fluoroscopic imaging devices as part of an initiative to reduce unnecessary radiation exposure to patients. Read more...
FDA To Set Standards For CT, Fluoroscopic Devices In Radiation Safety Effort
Full article reprinted from "The Gray Sheet"- February 16, 2010
FDA will develop new safety requirements for computed tomography and fluoroscopic imaging devices as part of an initiative to reduce unnecessary radiation exposure to patients. "The goal of FDA's initiative is to support the benefits associated with medical imaging while minimizing the risks," CDRH Director Jeffrey Shuren said in announcing the program Feb. 9. The first step will take place March 30-31, when FDA plans a public meeting to solicit input on what safeguards should be built into CT machines and fluoroscopes to ensure that patients receive an optimal radiation dose - "no more or less than what is necessary to produce a high-quality image," as an FDA white paper related to the initiative puts it. The new standards could include such things as a requirement that CT and fluoroscopy devices display, record and report equipment settings and radiation dose; an alert mechanism when the dose exceeds a level considered optimal for most patients; and a requirement that devices be able to capture and transmit radiation dose information to a patient's electronic medical record and to national dose registries, according to FDA. The standards also could include certain kinds of training for device users. Special Controls Guidance Planned In an interview with "The Gray Sheet," Shuren said the agency will consider requirements for new devices as well as those already on the market. Standards for the design of new devices will eventually be detailed in rulemaking and described in a special controls guidance document, Shuren explained. "But we don't have to wait until that's finalized," he said. "We'll start working with manufacturers immediately on new devices they're developing to make sure that safeguards are built in." For devices already on the market, Shuren said, FDA is "already beginning to explore if there are changes that could be made to the existing technologies, such as updates in software." The standard-setting effort is part of a multi-pronged approach to preventing excessive radiation exposure. In other actions, FDA will collaborate with the American College of Radiology and other professional organizations to develop diagnostic reference levels - or norms for radiation doses - for medical imaging procedures that use radiation. The agency is also recommending that groups such as ACR and the American College of Cardiology continue to develop criteria for appropriate use of CT, fluoroscopy and nuclear medicine procedures. With CMS, FDA will work to include key quality assurance practices in the accreditation criteria for stand-alone imaging facilities. The quality criteria will address a problem noted in the agency's white paper; namely, that patients undergoing the same type of medical imaging exam are subject to wide variations in radiation doses depending on which facility administers the exam. FDA will work to "empower patients and increase awareness" by helping develop a patient medical imaging history card that will allow people to track their medical imaging history and share it with their physicians. The card, to be created in collaboration with other groups, will be made available on FDA's Web site. "FDA is advocating two principles of radiation protection: appropriate justification of the radiation procedure and optimization of the radiation dose used during each procedure," a press release from the agency states. Ultrasound, MRI And Radiography Not Implicated The radiation safety initiative concerns only those types of procedures that use ionizing radiation to generate images of the body. Ultrasound, which uses sound waves, and magnetic resonance imaging, which uses radio waves and magnetic fields, are not at issue. The agency also notes that projection radiography procedures, including chest x-rays and mammography, use relatively low amounts of radiation. The safety initiative is focusing just on CT, fluoroscopy and nuclear medicine, all of which involve repeated or extended exposure to radiation and thus give patients a higher radiation dose than x-rays, FDA explains. As an example, the agency cites a July 2008 article in the journal Radiology stating that the adult effective dose from a CT exam of the abdomen is roughly equivalent to the adult effective dose from 400 chest x-rays. FDA also cites a March 2009 report by the National Council on Radiation Protection and Measurements which found that the U.S. population's total exposure to ionizing radiation - the form that can potentially cause damage to DNA - has nearly doubled over the past two decades, largely because of increased exposure from CT, interventional fluoroscopy and nuclear medicine. President Obama's fiscal 2011 federal budget request for FDA includes $250,000 and one extra full-time staffer to support the radiation safety initiative. FDA's budget documents state that "the consequences of ionizing radiation exposure are known to include future cancer induction. It is a fact that these doses can be substantially reduced and public health improved." Shuren said the $250,000 budget request will supplement existing resources being devoted to the initiative. "We already have the in-house expertise and the people to do it," he said, adding that FDA had been working on the issue of excessive medical radiation even before the New York Times ran a major story on the topic Jan. 24. "There will be many people involved," Shuren said, including "a combination of radiation biologists and physicists and software experts and radiologists and of course statisticians. We bring a wealth of expertise to the table." Congressional Hearing Expected Meanwhile, the House Energy and Commerce Committee's health subcommittee plans to hold a hearing on medical radiation issues, and ECRI Institute has scheduled a Feb. 17 web conference on how to efficiently manage CT radiation doses. The first public hint that FDA was becoming concerned came last October, when the agency announced an investigation into hundreds of cases of radiation overexposure from CT brain perfusion scans in California (The Gray Sheet' Dec. 14, 2009). Those cases involved CT imaging equipment manufactured by GE Healthcare and Toshiba. Numerous other companies market CT and fluoroscopic devices, however, and the broad initiative announced Feb. 9 is expected to be relevant to them all. - Mary Houghton
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