The US Food and Drug Administration (FDA) says safeguards for avoiding unnecessary exposure to medical radiation should be tightened and announced a new three-pronged initiative on Tuesday to increase oversight of the biggest contributors: computed tomography (CT), nuclear medicine studies, and fluoroscopy.

The agency announced that the three-pronged initiative “will promote the safe use of medical imaging devices, support informed clinical decision-making, and increase patient awareness of their own exposure”.

The FDA said CT, nuclear medicine, and fluoroscopic imaging were the greatest contributors to radiation exposure in Americans and use much higher radiation doses than other radiographic methods like standard medical X-rays, dental X-rays and mammography. For example, a patient undergoing a CT abdomen scan is exposed to the same amount of radiation as 400 chest X-rays.

Accidental exposure to very high amounts of radiation can cause injuries such as skin burns, hair loss and cataracts, and there is evidence that medical imaging exposure can increase a person’s lifetime cancer risk.

The agency said in a statement it was taking this step because while experts disagreed on the size of cancer risk linked to medical imaging exposure, most agreed that more could be done to reduce unnecessary exposure.

Acknowledging the valuable contribution that CT, nuclear medicine, and fluoroscopic imaging make to early diagnosis and improved treatment of disease and thereby saving lives, the FDA said they wanted to support the already strong dialogue between patients and medical professionals by helping them make better decisions about the risks and benefits of undergoing imaging procedures.

Dr Jeffrey Shuren, the FDA’s director for Devices and Radiological Health, told the media that:

“The amount of radiation Americans are exposed to from medical imaging has dramatically increased over the past 20 years.”

“The goal of FDA’s initiative is to support the benefits associated with medical imaging while minimizing the risks,” he added.

To promote safer use of medical imaging devices, the FDA wants federal agencies and healthcare professionals to work together and push two principles: ensure the procedure is justified in the first place and then ensure the right dose is used in each procedure.

The agency said it will seek to do this through its role as regulator of imaging devices. For example, it intends to issue target requirements for manufacturers of CT scanners and fluoroscopic devices to build extra safeguards into the equipment and train practitioners in safe use.

One suggestion is that the devices display, record and report the settings used and the dose, and give out an alert if it is above a certain reference level, such as a standard optimal dose.

Another suggestion is that the devices should record individual radiation doses and transmit them to patients’ electronic medical records and to national dose registries.

The FDA said a dose registry would bring together data from many imaging centers all around the US. It would help define and validate diagnostic reference levels and provide benchmarks for individual imaging studies.

The FDA urged that:

“Health care professional organizations continue to develop, in collaboration with the agency, diagnostic radiation reference levels for medical imaging procedures, and increase efforts to develop one or more national registries for radiation doses.”

Shuren said that working together, the FDA and other organizations hope to:

“Help patients get the right imaging exam, at the right time, with the right radiation dose.”

The FDA said it was planning to hold a public meeting on 30 to 31 March to discuss their proposals and seek further suggestions on the regulatory safeguards.

— more info on the initiative (FDA)

Source: FDA.

Written by: Catharine Paddock, PhD