Patients More Likely to Die from Disease than CT-induced Cancer

Young patients are 35 times more likely to die of their disease than from radiation-induced cancer from CT exams, researchers found.

Researchers analyzed the records of 23,359 patients between the ages of 18 and 35 who underwent abdominopelvic CT or chest CT exams from 2003 to 2007. Some patients were scanned more than 15 times. The results were presented at the American Roentgen Ray Society Annual Meeting this week in Vancouver, Canada.

In the chest CT group, 575 patients out of 8,133 were deceased after a mean follow-up of about four years. Twelve cases of radiation-induced cancer would have been expected in this group, based on the BEIR-VII method commonly used for determining CT-induced cancer incidence, according to study author Rob Zondervan. 

Among the abdnomino-pelvic CT group, 1,124 patients out of 15,226 were deceased after a mean follow-up of about 3.5 years. In this group, there were 23 cases of predicted cancer incidence, Zondervan said.

"Our results indicate that the risk from underlying disease overshadows risk from CT radiation-induced malignancy, even in young adults," he said.

Researchers further broke down the data based on the number of CT exams. Patients who had only one or two scans had the most predicted cases of CT-induced cancer: 20 out of the 35 predicted cases. "This seeming anomaly arises from the much greater number of young adults who get one or two scans," said Zondervan. "These results do emphasize that we need to focus our radiation reduction efforts on patients who are very rarely scanned as well as those who are more frequently scanned."