Lifetime cancer risks from X-rays for children ‘relatively low’
Tuesday 10 June 2014 – 12am PST
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Parents have plenty to worry about when it comes to the health and safety of their kids. But a new study published in the American Heart Association journal Circulation suggests radiation from standard X-rays is low and does not raise lifetime cancer risks for most children.
To adequately study the effects of radiation in children, researchers followed 337 children under the age of 6 who had surgery for heart disease at Duke University Medical Center in North Carolina.
The team, led by Dr. Kevin Hill, cardiologist and assistant professor of pediatrics at Duke, says they studied children with heart disease because they are exposed to more imaging tests than children in most other groups.
The imaging procedures the children underwent totaled nearly 14,000. This includes X-rays, computed tomography (CT) scans and cardiac catheterization procedures using video X-rays – known as fluoroscopies.
Overall, the team found that the cumulative dose of ionizing radiation for the average child in the study was lower than the annual background exposure in the US.
Though this finding can certainly put many parents’ minds at ease, the team did find that some children with complex heart disease who are exposed to large cumulative doses of radiation have increased lifetime risks of cancer – up to 6.5% above baseline.
Commenting on their findings, Dr. Hill says:
“There are definitely times when radiation is necessary. But it’s important for parents to ask and compare in case you can avert potentially high exposure procedures. Often there are alternative or modified procedures with less radiation, or imaging may not actually be necessary.”
‘Awareness greatest means to reducing exposure’
This study is the first to quantify cumulative radiation doses in child heart patients and predict lifetime cancer risks, based on types of exposures, the team notes.
After assessing children with heart disease who had undergone imaging procedures, researchers found that the cumulative dose of ionizing radiation for the average child in the study was lower than the annual background exposure in the US.
They reviewed medical records to find the most common imaging procedures and calculated how much radiation organs absorbed during each procedure. Then, they used a National Academy of Sciences report to assess the children’s lifetime cancer risks.
In detail, the study found that:
Lifetime cancer risk increases spanned from 0.002% for chest X-rays to 0.4% for CT scans and cardiac catheterizations.
Of the imaging exams, X-rays accounted for 92%.
Cardiac catheterizations and CT scans accounted for 81% of overall radiation exposure.
Because they are more likely to get cancer of the breast and thyroid, girls have double the cancer risk of boys.
Dr. Hill explains that, though they used child patients with heart disease for their study, cancer risks would be the same for any child without heart disease who is of the same age and who was exposed to the same radiation levels.
“Simple awareness is one of the greatest means to reducing exposure,” he says. “Health care providers should consider tweaking protocols to limit radiation doses and balance risks and benefits of every imaging study they do.”
In 2013, Medical News Today reported on a study that suggested an anti-cancer compound present in cruciferous vegetables, such as cabbage, cauliflower and broccoli, protects rodents from radiation damage.
Written by Marie Ellis