X-rays and Children: FDA Issues Guidance to Minimize Dose

Posted on November 28, 2017 by FDA Voice

By: Vasum Peiris, M.D., M.P.H.

In medicine, knowledge is power and the information and knowledge gained from medical imaging have transformed the way medicine is practiced in less than a generation. Advances in X-ray imaging have evolved dramatically and span simple projection X-ray examinations to sophisticated 3-D techniques (computed tomography or ‘CT’) to fluoroscopy, which features dynamic images helpful in both diagnosing and treating certain conditions.

These advances mean that we can find problems earlier, when a treatment is most likely to be successful. As a pediatrician and a cardiologist, I have relied upon these increasingly accurate tests, and seen firsthand their life-saving benefits among my patients.

With these technological gains, however, comes a cost. X-ray exams use ionizing radiation, and CT and fluoroscopy require a relatively higher dose than plain X-rays. This radiation, if excessive, has been associated with an increased risk of cancer. This risk is slight – and is far outweighed by the benefits for a patient in need of a diagnosis or effective treatment plan. But it is real and compels us to be proactive about reducing patients’ exposure as much as possible, without jeopardizing the diagnostic quality of the exam.

Nowhere is this responsibility more important than in children. Children have a higher sensitivity to radiation dose, and a longer lifetime over which the risk of cancer can accumulate. Thus, it is imperative that clinicians use X-ray procedures only when necessary, and at settings that ensure the dose is ‘right sized’ for these smaller patients.

There are two ways that children’s exposure can be reduced. The first is by ensuring that X-ray exams and procedures are only ordered when they are clinically necessary. Medical professionals do their best to choose the right exams for their patients and are influenced by several factors including regional or institutional expertise. When appropriate, alternatives to X-ray procedures, such as ultrasound and magnetic resonance imaging (MRI) should be considered.

The other way to limit exposure is to add dose reduction features to the imaging equipment itself. Special equipment settings and techniques can optimize the amount of radiation a patient receives. FDA works closely with equipment manufacturers in our mission to ensure that the devices they manufacture are safe and effective.

In fact, X-ray manufacturers, FDA, health care providers, medical physicists and many others have collaborated for years to develop dose reduction tools and put them to work on behalf of patients. Many new technologies have emerged through these interactions and been adopted by industry and imaging professionals.

As a clinician, I know that even more can be done. On Nov. 28, 2017, FDA published a final guidance titled “Pediatric Information for X-ray Imaging Device Premarket Notifications.” This guidance recommends that manufacturers include dose reduction features in their equipment designs and pediatric resources when they develop and manufacture X-ray equipment.

What’s more, we suggest that industry ensure that these tools are straightforward to implement and that clear, understandable instructions on how to optimize dose should be easy for imaging staff to find and use. These recommendations, while significant and capable of making an important difference in the amount of radiation pediatric patients receive, also strike the right balance between safety and burden to manufacturers.

Clearly, FDA does not wish to signal that children should not receive X-ray imaging exams. There are clinical questions that only X-rays, CTs, and fluoroscopy can answer or can answer better than other options. But as experience has taught us, if a clinician determines that an X-ray scan is needed, it can be and should be optimized for children.

Vasum Peiris, M.D., M.P.H., is Chief Medical Officer for Pediatrics and Special Populations, in FDA’s Center for Devices and Radiological Health