Study Finds Majority of Pediatric Head CTs Deliver Excess Radiation, Raising Long-Term Cancer Risk
A recent study published in the European Journal of Radiology reveals that a significant percentage of pediatric head CT scans expose children to excessive radiation, raising serious concerns about long-term cancer risks. Researchers found that up to 77% of exams analyzed resulted in radiation doses that exceeded what is considered necessary, often due to over-scanning beyond the targeted anatomy.
“The increasing reliance on computed tomography in pediatric clinical practice has raised major concerns regarding radiation-induced cancer risks,” said lead author Farshid Mahmoudi from the School of Allied Medical Sciences in Iran. “Although the brain is relatively less radiosensitive than many other organs, children are particularly more susceptible to radiation-related harm due to their smaller body size, greater tissue sensitivity, and longer post-exposure life expectancy.”
The research team evaluated more than 100 pediatric head CT exams conducted across three hospitals. To estimate radiation doses received by individual organs, the team used size-specific dose estimates along with Monte Carlo simulations. They also calculated lifetime attributable cancer risks based on patient age and sex, identifying a concerning relationship between scanning practices and potential future harm.
The study found that the highest radiation exposure occurred in the brain, eye lenses, oral mucosa, salivary glands, red bone marrow, and thyroid. Among all organs, the thyroid emerged as the most at-risk for long-term effects, particularly in female patients. The study indicated a disproportionate rise in lifetime attributable risk for thyroid cancer, leukemia, lung cancer, and breast cancer among younger children, noting that “age and risk had an inverse relationship” and girls showed a higher susceptibility to radiation-induced malignancy.
Notably, over-scanning was observed in 78% of the reviewed exams, and this was exclusively associated with scans performed in the caudocranial direction. This practice, often used to avoid missing critical anatomical landmarks, inadvertently extended the scan range and increased radiation to sensitive adjacent tissues. According to the study, this scanning approach could elevate the risk of thyroid cancer in young girls by more than 250%.
“This emphasizes the importance of targeted training for technologists in accurately defining caudal anatomical landmarks, strict adherence to pediatric scanning protocols, and considering automated range-selection tools,” the researchers urged. “Reducing unnecessary caudal over-scanning is crucial to minimize radiation dose and enhance patient safety in pediatric brain CT examinations.”
While CT imaging remains a vital diagnostic tool, especially in emergency and neurological settings, the authors highlight the urgent need for improved training and stricter adherence to pediatric-specific protocols. They suggest that radiology departments implement automated tools and reinforce education around scan range planning to ensure safer imaging for young patients.