In May, the FDA¹ released for public comment a guidance document intended to ensure that manufacturers’ imaging devices are either suited for pediatric use or labeled with a warning that cautions against use in pediatric populations.
Citing the increased radiosensitivity of children (as compared with that of adults), the greater timeline along which overexposure could manifest itself as cancer, and the potential for children to be exposed to excessive radiation when machines calibrated principally for adults are used, the document would require manufacturers to explicitly incorporate pediatric settings, labeling, displays, and software on all new equipment or label it to caution against pediatric use.
Although everyone takes notice when the FDA issues such guidance, Marilyn J. Goske, MD, who chairs both the Alliance for Radiation Safety in Pediatric Imaging and the pediatric interest group of the ACR® Dose Index Registry, says that the increased focus on pediatric dose mitigation and patient safety is a slow crescendo that began about a decade ago.
Goske, who is also a professor of radiology and pediatrics at Cincinnati Children’s Hospital Medical Center in Ohio, says, “The work that groups like the Society for Pediatric Radiology did helped lay the groundwork to impel discussions about the importance of lowering pediatric imaging dose.”
Although the weeks leading up to the FDA announcement had been filled with releases of high-profile research on the harmful effects of ionizing radiation on children, Goske notes, “I think it’s steady work by many that’s made it seem like it’s come out of nowhere. The recent article² in Lancet really starting to add to our body of knowledge on medical imaging that’s not being extrapolated from other sources, like the atomic-bomb information.” The things that excite her most are “the collaboration and the communication between critical groups,” Goske says.
An Opportunity to Communicate
Image Gently® sent eight physicians and other medical-imaging professionals to Device Improvements for Pediatric X-ray Imaging (a public workshop held by the FDA on July 16 in Silver Spring, Maryland) to speak specifically with the Medical Imaging & Technology Alliance (MITA), the FDA, and device manufacturers about the particular challenges inherent in trying to image children. “This was our opportunity to communicate with them about what we feel in the trenches,” Goske says.
“We know that 90% of pediatric CT scans are performed in adult-focused practices, not in children’s hospitals,” she adds. “We’re asking the radiologists and radiologic technologists to make sure that they’re doing those 10 CTs a day as safely as possible. This meeting with the FDA and MITA gives us an opportunity to put the spotlight on kids and how to use this equipment and adapt it for use with children.”
Robert A. Uzenoff, executive director, clinical science, FUJIFILM Medical Systems USA, who also attended the workshop, views the event as “a continuation of the collaboration with users and regulators that we’ve had,” he says. “The manufacturers are delighted to have this conversation, but our concern is that some technical factors of the newly required protocols—technical settings such as peak kilovoltage and the use of additional filtration, which focal spot to use, and at what distance to acquire the image—relate to the quality of the exam, and we’re not aware of any professional consensus of what those should be; we’re reluctant to set a standard there.”
To Each His Own
Uzenoff points out that many of those who attended the FDA event in July—MITA and Fujifilm among them—also attended the CR/DR Vendor Summit (sponsored by Image Gently and hosted by the Mallinckrodt Institute of Radiology at Washington University School of Medicine) on February 4, 2010, in St Louis, Missouri.
At that event, manufacturers explained their intention to offer devices with the features identified in the 2008 International Electrotechnical Commission’s standard 62494-1, establishing a standard method of representing exposure index and any deviation from the target index for each exam, Uzenoff says, which benefits pediatric practice, but is not specific to pediatric imaging. Manufacturers were heavily involved in the development of the standard. That summit “certainly validated manufacturers’ decisions to go in that direction,” he says.
“Each manufacturer, on its own timetable, is adopting (or has adopted) it,” he reports.