Deadly Damage from Decades Past

Whether as a result of numerous computer-tomography (CT) scans or cancer treatment, children exposed to head-and-neck radiation are at an increased risk of thyroid cancer years later.

A study from the University of Rochester Medical Center, thought to be the lengthiest of its kind, may point to why there are increased incidences of thyroid cancer as the general public becomes increasingly exposed to higher doses of radiation used in imaging tests such as CT scans.

According to lead author Jacob Adams, M.D., and associate professor in the Department of Community and Preventive Medicine at URMC, ionizing radiation acts as a carcinogen in the roughly 1 million CT scans performed every year on children aged five or younger.

The study aimed to measure long-term impact on thyroid cancer from medical irradiation. Researchers found evidence strongly suggesting individuals exposed to irradiation from multiple CT scans to the head, neck and chest in early childhood and children whose upper bodies are treated with radiotherapy have a lifelong increased risk of thyroid cancer.

The study looked at rates of thyroid cancer in a group that was treated with lower-dose chest radiotherapy between 1953 and 1987 and compared the health statuses of those in the group to their siblings, who had not received radiation, in a re-survey of the population between 2004 and 2008. Researchers found incidences of thyroid cancer in 50 of the 1,303 irradiated patients compared to only 13 of the 1,768 siblings.