Patients win with a balanced approach to CT scanning


Robert MacDougall is clinical medical physicist for Boston Children’s Hospital Department of Radiology. Michael Callahan, MD, is a radiologist in Boston Children’s Department of Radiology and a member of the steering committee for the Alliance for Radiation Safety in Pediatric Imaging.

A recent opinion piece published in the New York Times, titled “We Are Giving Ourselves Cancer” (Op-Ed, Jan. 31), has provoked fear and anxiety in patients and parents over the use of computed tomography (CT) scans. This op-ed is the latest in a series of lay press articles to focus on the potential harm of radiation in medical imaging.

While the authors raise several important points, they fail to provide context and acknowledge the benefits of CT imaging, including the elimination of many unnecessary surgeries and improved diagnosis of cancer and other serious health conditions. This unbalanced view potentially presents a real and immediate risk to patients, who may forego CT exams that could improve their care because of concerns related to radiation exposure.

The relationship between cancer risk and radiation exposure is not well understood. Estimation of future cancers in a large population is not based on sound science: The principal data source—studies of survivors of the atomic bomb explosions in Japan—does not translate well to medical radiation and can be misused to create sensationalistic estimates of future cancer incidence and deaths.

In a policy statement, the American Association of Physicists in Medicine explains: “Discussion of risks related to radiation dose from medical imaging procedures should always be accompanied by acknowledgement of the potential benefits the procedure provides. Risks of medical imaging at effective doses below 50 mSv for single procedures … are too low to be detectable and may be nonexistent.” The vast majority of routine CT scans fall well below this level.

Nonetheless, once an exam is ordered, it must be performed in the safest way possible.

As a leading health institution caring for children, who are especially vulnerable to radiation, Boston Children’s Hospital was one of six pediatric hospitals to participate in the Quality Improvement Registry in CT Scans in Children Consortium(QuIRCC) through the American College of Radiology’s Dose Index Registry. This national database allows institutions to collect dose information from a large number of CT scans and develop a consensus for optimal CT scan doses.

Data gathered from the QuIRCC were recently used to create Diagnostic Reference Ranges for pediatric abdominal-pelvic scans. Such guidelines allow hospitals to keep doses as low as reasonably achievable while providing image quality that allows the radiologist to confidently answer the diagnostic question.

While increased regulation from the Joint Commission and U.S. Food and Drug Administration could help identify and mitigate inappropriate practices on a national scale, the responsibility of ensuring patient safety is in the hands of individual hospitals. That responsibility should include collaboration between radiologists and medical physicists on a daily basis to provide the safest environment for both children and adults.