Cracking Down: CT Radiation Dose Control

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 - Dose

Medical imaging procedures offer unprecedented abilities for physicians to detect, diagnose and treat a wide range of diseases and medical problems. An estimated 68 million CT scans, for example, are performed every year in the United States. That’s up from 3 million in 1980. Along with the new capabilities, however, are new concerns about radiation exposure. The issue has come to a head—from education and awareness to updated guidelines and equipment advances.

Radiation dose awareness in imaging studies started a long time before the New England Journal of Medicine (NEJM) published an article last November warning that the overuse of diagnostic CT scans may cause as many as 3 million additional cancers in the United States during the next two to three decades. That’s a risk the radiology community has been well aware of for a long time. But the NEJM article revived the quest to control dose for patients and clinicians. The challenge now is expanding that awareness to the rest of the medical community.

“The traditional approach to diagnostic testing can be characterized as ‘leave no stone unturned’ to achieve the most certain diagnosis possible,” says David A. Schauer, ScD, CHP, executive director of the National Council on Radiation Protection and Measurements. “Under this philosophy, as long as an imaging examination has any chance at all of demonstrating a diagnosis suggested by the clinical clues, then its use is considered reasonable.”

That approach doesn’t take into consideration the impact that any radiation involved in treatment would have on the patient, he points out. “It is clear that breaking this habit and beginning to link selection of patient for imaging examination to likelihood of effect on treatment choice or on patient outcome can help to reduce the economic problems resulting from imaging uses which now adversely affect healthcare costs and to reduce unnecessary radiation exposure of the patient.”

The Alliance for Radiation Safety in Pediatric Imaging launched its new Image Gently campaign in January, with the goal of raising awareness of the opportunities to lower radiation dose when imaging children. At least 600 practices have already signed on and pledge to practice in accordance with the campaign’s recommendation. The medical community has been extremely receptive, says Donald Frush, MD, chair of the American College of Radiology (ACR) Pediatric Imaging Commission.

“This was not taken on as a scare campaign or adversarial campaign,” he says. “It was always based fundamentally on getting information out to practices, organizations and individuals.” Essentially, the campaign is trying to do everything that the NEJM article did not, he says. That includes spreading the word that “CT is really helpful, it saves lives and there are ways to do it appropriately.”

Frush says there has been a growing interest over the past six or seven years to look at radiology’s effects specifically in children and young adults. Some of the cancers that the NEJM article predicted are related to radiation. Since they can take 30 years to develop, excessive exposure to radiation is especially important when imaging children. A two-year-old, for example, has a much higher chance of a 75-year-old of developing one of these cancers. Plus, children are more radiosensitive because their tissues and organs are still dividing and growing. “That kind of tissue has more of a chance of having effects from radiation than tissue simply repairing itself like an adult’s,” he explains. 

Radiologists who specialize in pediatric radiology understand the need to image children differently, says Priscilla F. Butler, MS, senior director, Breast Imaging Accreditation Programs for the ACR, who also was involved in the Image Gently campaign. Most pediatric imaging in the United States, however, is done at community hospitals that probably don’t have a pediatric radiology specialty. “The whole purpose of the initiative was to raise awareness among the radiologists who don’t do as many pediatric patients.”

The campaign has enjoyed “extremely positive feedback,” she says. “Techs feel empowered to bring issues to radiologists. This has been a joint effort among the different players in the radiology department—technologists, radiologists and medical physicists.” Based on the positive response, the ACR is working on an educational campaign for referring physicians and patients and families. “We have to be careful,” she says. “We don’t want