(HealthDay News) — Exposure to medical radiation from computed tomography (CT) scans is associated with an increased risk for thyroid cancer and leukemia, according to a study published online Nov. 19 in JNCI Cancer Spectrum.
Yu-Hsuan Shao, Ph.D., from the Taipei Medical University in Taiwan, and colleagues examined the correlation between medical radiation from CT scans and the risk for thyroid cancer, leukemia, and non-Hodgkin lymphoma (NHL) among adults. A total of 22,853 cases of thyroid cancer, 13,040 leukemia cases, and 20,157 NHL cases were included with their matched controls.
The researchers found that exposure to medical radiation from CT scans correlated with elevated risks of thyroid cancer and leukemia (odds ratios, 2.55 [95 percent confidence interval, 2.36 to 2.75] and 1.55 [95 percent confidence interval, 1.42 to 1.68], respectively). Compared with men, women had a stronger elevated risk for thyroid cancer and leukemia in association with medical CT. Overall, in patients with NHL, there was no significant association between the risk for cancer and CT scans (odds ratio, 1.05; 95 percent confidence interval, 0.98 to 1.12); however, in patients ≤45 years, increased risks were seen. For all three cancers, there was a clear dose-response correlation in patients ≤45 years.
“CT scans are an important diagnostic tool, but need to be used judiciously,” the authors write. “Strategies to reduce radiation exposure from an appropriate utilization of medical imaging would definitely optimize the benefit-risk ratio of CT scans.”