CT in Kids: Balancing Risks, Benefits
At Graykoski's facility, which is not pediatric-focused, the staff is "acutely aware of this issue." Consultations with the radiologist prior to the ordering of scans are common, protocols are in place to limit the amount of radiation exposure in CT scans, and the newest-generation equipment, which has built-in capabilities to limit exposure, is available. "We're trying to do everything we can to make sure that the risks associated with imaging are offset by the benefits to be realized from it," Graykoski says.
The National Cancer Institute stresses that "the individual cancer risks associated with CT scans are small," with lifetime risks estimated at less than 1 in 1,000. However, as the data indicate, children are increasingly being exposed to those risks, and they may be particularly vulnerable. "From age 0 to 14 especially, the DNA is rapidly replicating, and that's when it is most vulnerable to insult from radiation," Graykoski explains.
Furthermore, "the risk of radiation is a cumulative lifetime risk. It's not the case that you just take a picture and in 24 hours, the side effects are gone," he adds. Young children have the rest of their lives to accumulate radiation exposure from additional imaging tests and from natural circumstances. (The average effective dose of natural background radiation is 3 mSv per year in the United States.)
"It's not that we have the crisis right now—this is a problem that will be growing into the future," Graykoski says, especially if the boom in the use of this imaging modality does not abate. "And of course, our concern is for safety—we don't want to be responsible for causing harm to any patient, especially a youngster."
First, Do No Harm
Any clinician who is considering ordering CT for a pediatric patient may want to paraphrase a classic World War II adage. Instead of asking, "Is this trip really necessary?" the question should be, "Is this test really necessary?"
As with any type of test, the decision to order CT should be made after careful consideration of the risks and benefits, as well as how the specific test will change the clinical management of the patient. Will the child be able to go home? Will he/she require an operation? Will the child need to be admitted?
Health care providers "need to be absolutely sure that the results of that test are actually going to help them make a decision or a diagnosis," Poirier says. "And if time will help you make a diagnosis and does not put the patient at risk, then sometimes you don't do the test. You talk to the family, and maybe you admit the patient or maybe you have them follow up the next day."
A classic example is a child who has experienced head trauma; perhaps he or she was stunned at the time of the event or had an episode or two of vomiting. "It used to be pretty routine that all of those kids would get CT evaluations," Poirier says. "The recent studies have shown that those CT scans don't change the management of those patients. It's just unnecessary radiation."
Instead, it may be more appropriate to watch the patient in the ED until it is clear his/her condition is not going to deteriorate, ensure the family has adequate follow-up, or even keep the child in the ED or admit him/her for overnight observation. Of course, there are geographic factors to consider as well.
"A lot has to do with the comfort level of the parents—are they comfortable waiting and watching? Is it convenient?" says Graykoski, whose facility is in west-central Wisconsin. "We have patients who are two hours away from the hospital, so it's not the easiest thing to say, 'Well, go home; if it gets worse, bring him back.' A couple of hours can certainly be very serious."
Communication is key so that parents have a full understanding of why an imaging study may or may not be in their child's best interest. Despite reports in the mainstream media about the radiation risk of CT, none of the clinicians interviewed has yet encountered parents who refused CT because of that risk. Graykoski says he is usually the one to broach the subject with parents.
"Most parents, I think, want to hear that discussion," he says, "but I would say the majority want the reassurance of having some of these tests done and frequently will err on the side of getting that information and ruling something out, as opposed to thinking about the future effect of radiation accumulation."
