© Andrew Testa/The New York Times
A push to reduce unnecessary radiation exposure from CT scans, above, nuclear medicine studies, and fluoroscopies.
The FDA has announced a plan to reduce patients' unnecessary exposure to radiation from three different medical imaging tests. The three-pronged strategy will focus on increasing the safety of the devices, increasing patient awareness of risks, and improving the ability of patients and doctors to make informed decisions.
The tests in question are computed tomography (CT) scans, nuclear medicine studies and fluoroscopy. CT scans produce three-dimensional images of different areas of the body, nuclear medicine studies involve consumption of a radioactive substance to observe its motion through the body, and fluoroscopy uses a continuous beam of radiation to produce a real-time, moving image.
"The FDA continues to support a strong dialogue between patients and physicians over the medical necessity and risk associated with these types of imaging studies," the agency said. "However, like all medical procedures, CT, nuclear medicine, and fluoroscopy pose risks."
The FDA chose to focus on the three procedures because together they provide the single greatest source of radiation exposure for the U.S. population. CT scans, nuclear medicine studies and fluoroscopy all deliver much higher doses than other radioactive imaging procedures, such as mammography or X-rays. For example, a single CT abdomen scan uses as much radiation as 400 chest X-rays or 800 dental X-rays.
Yet in spite of the risks, which according to the FDA include cancer, cataracts and burns, the use of radioactive imaging tests has become much more common in the United States in recent years.
"The amount of radiation Americans are exposed to from medical imaging has dramatically increased over the past 20 years,"
said Jeffrey Shuren, director of the FDA's Center for Devices and Radiological Health.
The FDA plans to reduce unnecessary exposure by encouraging "appropriate justification" of all radiation tests, as well as "optimization of the radiation dose."
"Working together," said Shuren, "the FDA and other organizations hope to help patients get the right imaging exam, at the right time, with the right radiation dose."
Under the first prong of its three-prong strategy, the FDA seeks to encourage safer use of the three techniques. Toward this goal, it plans to require manufacturers of radiation imaging devices to implement specific safeguards in the machines and implement standardized training for all device operators.
The specific requirements to be established have yet to be determined, but might include making all devices display, record and report radiation doses and other relevant settings; having devices issue alerts when a higher-than-normal dose is entered; and making devices immediately add information about each test to a patient's permanent medical record and a national dose registry.
The FDA is also working with the Centers for Medicare and Medicaid Services to impose new accreditation requirements on all facilities that perform radioactive imaging, with the goal of improving oversight and safe device use.
In order to improve patient awareness, the FDA is working with a number of other organizations to design a patient medical imaging history card, which would record every radiation test undergone by a specific patient in a fashion similar to an immunization card. This card (which will also be available via the FDA web site) could then be presented to physicians to inform them about the patient's prior lifetime radiation exposure.
In service of the final goal, informed consent, the FDA is encouraging the development of a national radiation dose registry so that researchers can monitor nationwide radiation exposure and help produce more targeted recommendations on when the risk of a procedure outweighs its benefits.
"Health care decisions made by patients and their physicians should include discussions of the medical need and associated risks for each procedure," the agency said.