(RxWiki News) For children with heart disease, exams using radiation allow doctors to see images of their hearts. But for some children, this exposure to radiation also might pose a risk for cancer later in life.
A recent study examined how radiation imaging affects cancer risk in children with heart disease, who are regularly exposed to imaging exams.
The researchers determined how often children with heart disease received doses of radiation, then used models to estimate how that radiation would affect their risk of developing cancer in their lifetimes.
These researchers found that most children with heart disease received a relatively low dose of radiation. However, certain children with more complicated heart issues received more radiation.
The authors of this study recommended that healthcare providers work to reduce long-term cancer risk among children who have been exposed to high doses of radiation.
"Ask your child's doctor about the potential risks of imaging tests."
Kevin Hill, MD, MS, assistant professor of pediatrics in the cardiology division of Duke University School of Medicine, led this study.
According to Dr. Hill and team, children with heart disease are usually exposed to radiation from imaging exams like X-rays.
Children have developing organs and tissues and may be exposed to more radiation over their lifetimes than adults.
This study looked at the cumulative effect of radiation on cancer risk among children with heart disease.
The study included 337 children who were 6 years old or younger and had previously undergone one of seven surgeries for heart disease.
The researchers examined the children's medical records and found that the 337 participants had been exposed to a combined total of 13,932 radiation exams.
On average, each child had undergone 17 examinations. The vast majority of the imaging exams (more than 92 percent) were X-rays.
The researchers then estimated lifetime risk of cancer using models obtained from the Committee on Biological Effects of Ionizing Radiation. These models evaluate how much radiation would increase one's risk of getting cancer, taking into account age at exposure and sex.
The researchers found that the children with more complex heart disease — for example, those who had received a heart transplant — received greater cumulative exposure to radiation.
However, for the average child in the study, the overall dose of radiation was less than what the average American would be exposed to each year from soil, building materials and the air.
The average participant's lifetime risk of cancer was around 0.07 percent higher than a person who had not been exposed to much radiation.
On the other hand, some participants with more complicated heart disease had an estimated risk of cancer up to 6.5 percent more than a person without radiation exposure from imaging.
The researchers also found that the lifetime cancer risk increased between 0.002 percent to 0.4 percent per radiation exam, depending on how large the radiation dose was.
They also found that girls had double the cancer risk compared to their male counterparts because they are more likely to develop breast and thyroid cancers.
The researchers concluded that the cancer risk effect of radiation on children with heart disease varied widely depending on the child's condition, radiation dose and sex.
Overall, radiation imaging did not increase the children's cancer risk by very much, according to the authors.
However, they suggested that healthcare providers should work to reduce long-term cancer risk among higher-risk children who have been repeatedly exposed to radiation.
This study was published in Circulation on June 9.
The research was funded by the National Center for Advancing Translational Sciences and the Mend a Heart Foundation. One of the authors disclosed receiving financial support for his work on radiation.