The use of CT, or CAT scans, a tool essential for medical imaging using X-rays and a computer, has increased over the years.
CT scan improves diagnostic accuracy but unfortunately, it delivers higher radiation doses than other tests.
During the research, scientists evaluated leukaemia and brain tumour risks following exposure to radiation from CT scans in childhood.
The study found a dose-response relationship with radiation dose to the brain while the cancer incidence was 1.5 times higher than expected.
Relative risks increased to between two and four for the highest dose category.
The researchers observed no association for leukaemia. Radiation doses to the bone marrow, where leukaemia originates, were low.
“Epidemiological studies of cancer risks from low doses of medical radiation are challenging, said Michael Hauptmann, the study’s principal investigator.
“Nevertheless, our careful evaluation of the data and evidence from other studies indicate that CT-related radiation exposure increases brain tumour risk.
“Careful justification of pediatric CT scans and dose optimisation, as done in many hospitals, are essential to minimise risks.”
The study was published in the Journal of the National Cancer Institute.