A study published in the Canadian Medical Association Journal (CMAJ) this week said children who have too many CT scans (computed tomography) are at risk of developing some cancers, leukemia and lymphoma later in life.
The study was authored by Wei-Hao Wang, Chia-Yu Sung, Shih-Chung Wang and Yu-Hsuan Joni Shao; a group of scientists at the Taipei Medical University Hospital in Taiwan.
The authors wrote that because it is known that children are more susceptible to radiation than adults, the aim was to explore the possible risks to children and teens for radiation exposure before the age of 18. The study suggested there should be more prudent use of CT scans for young people.
The research found that in cases where a child was exposed to four or more CT scans, the child "had an elevated incidence" of developing intracranial tumours, leukemia or lymphoma.
The researchers found more than 7,800 cases of individuals under the age of 25 with newly diagnosed cancers that occurred three or more years from the date of receiving their last CT scan.
The data also showed that individuals who had only one CT scan did not have any increased risk of any of the previously mentioned cancers. The study said this was the same result for any patient found to have never had a CT scan.
It was different for those who had multiple scans, said the study.
"Receiving four or more CT scans at or before six years of age was associated with the highest risks of cancer, followed by ages seven–12 years and 13–18 years," said the study.
The study was carried out in what the authors described as a population-based case-control study using data from Taiwan's publicly-funded health care system, from 2000 to 2013.
In interpreting the study, the authors wrote that the findings underscore the importance of the prudent use of CT scans.
"Exposure to a single CT scan was not associated with increased risks of subsequent intracranial tumours, leukemia or lymphoma among children; however, we observed increased cancer risks among those with four or more CT scans, especially among younger children. Although these cancers are uncommon, the findings of this study underscore the importance of prudent use of CT in the pediatric population," said the study.
The study's conclusion statement was as follows:
"This study found that exposure to a single CT scan at or before 18 years of age was not associated with the development of subsequent intracranial tumours, leukemia, non-Hodgkin lymphoma and Hodgkin lymphoma during childhood, adolescence and early adulthood,” said the study.
“Children who received multiple CT scans had higher risks of intracranial tumours, leukemia and non-Hodgkin lymphoma, but not Hodgkin lymphoma. Younger children appeared vulnerable to cancer risks associated with repeated CT exposure. Although these tumours are uncommon, these results indicate that judicious CT usage and radiation-reducing techniques should be advocated."
The full text of the study can be found online here.
Len Gillis covers mining and health care for Sudbury.com.