CT Scans may Heighten the Risk of Brain Cancer

CT scans may increase the risk of brain cancer, research at the Oxford University Press finds. This pattern of excess cancer risk may be partly due to confounding by indication, because the incidence of brain tumors is higher in the cohort than in the general population.

Computed tomography (CT) scans may increase the risk of brain tumors, a new study finds.

The use of computed tomography (CT) scans has increased dramatically over the last two decades. CT scans greatly improve diagnostic capabilities (which improve clinical outcomes) but they deliver higher radiation doses than other tests. Therefore, radiation protection is a concern, especially among children, who may receive higher radiation doses, are more susceptible to radiation-related malignancies than adults and have more time to show effects from the potential risk.

About Brain Tumor
Brain tumors are the abnormal growth of brain cells that may be benign or metastatic. Brain tumors account for about 2.4% of all the tumor diagnosesandare most challenging due to their critically delicate location.

‘CT scans may increase the risk of brain cancer especially for children.’

The most common malignancies caused by radioactivity among children and young adults are leukemia and brain tumors. Researchers therefore evaluated leukemia and brain tumor risks following exposure to radiation from CT scans in childhood.

For a nationwide group of 168,394 Dutch children who received one or more CT scans between 1979 and 2012, researchers obtained cancer incidence and vital status by record linkage. They surveyed all Dutch hospital-based radiology departments to ascertain eligibility and participation. In the Netherlands, pediatric CT scans are only performed in hospitals.

Overall cancer incidence was 1.5 times higher than expected. For all brain tumors combined, and for malignant and nonmalignant brain tumors separately, dose-response relationships were observed with radiation dose to the brain. Relative risks increased to between two and four for the highest dose category. The researchers observed no association for leukemia. Radiation doses to the bone marrow, where leukemia originates, were low.

Brain Tumor in Children - Types, Causes, Symptoms, Diagnosis & Treatment
An abnormal growth of cells in the brain is called brain tumor. Most tumors arise within the brain (primary). They can be benign or cancerous.

The researchers caution that this pattern of excess cancer risk may be partly due to confounding by indication, because the incidence of brain tumors was higher in the cohort than in the general population. CT scans are sometimes used to identify conditions associated with an increased tumor risk; the reason these children had CT scans may be associated with their risk of developing cancer.

"Epidemiological studies of cancer risks from low doses of medical radiation are challenging, said the study's principal investigator, Michael Hauptmann. "Nevertheless, our careful evaluation of the data and evidence from other studies indicate that CT-related radiation exposure increases brain tumor risk. Careful justification of pediatric CT scans and dose optimization, as done in many hospitals, are essential to minimize risks."

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Glioblastomas are tumors that arise from astrocytes that make up the supportive tissue of the brain. Glioblastomas are usually highly malignant.

Source-Eurekalert

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