DNA damage seen in patients undergoing CT scanning

“We now know that even exposure to small amounts of radiation from computed tomagraphy scanning is associated with cellular damage,” said Patricia Nguyen, MD, one of the lead authors of the study and an assistant professor of cardiovascular medicine at Stanford. “Whether or not this causes cancer or any negative effect to the patient is still not clear, but these results should encourage physicians toward adhering to dose reduction strategies.”

The study will be published online July 22 in the Journal of the American College of Cardiology: Cardiovascular Imaging. Won Hee Lee, PhD, and Yong Fuga Li, PhD, both postdoctoral scholars, are the study’s other lead authors.

“The use of medical imaging for heart disease has exploded in the past decade,” said Joseph Wu, MD, senior author of the study. Wu is a professor of medicine and of radiology and the director of the Stanford Cardiovascular Institute. “These tests expose patients to a nontrivial amount of low-dose radiation. But nobody really knows exactly what this low-dose radiation does to the patient. We now have the technology that allows us to look at very subtle, cell-level changes.”

Along with the burgeoning use of advanced medical imaging tests over the past decade have come rising public health concerns about possible links between low-dose radiation and cancer. The worry is that increased radiation exposure from such diagnostic procedures as CT scans, which expose the body to low-dose X-ray beams, can damage DNA and create mutations that spur cells to grow into tumors.

‘Legitimate concerns’

But there has been limited scientific evidence to date that shows the effects of this low-dose radiation on the body, according to the study. Currently, there is a bill winding its way through Congress to fund more research on the health effects of low doses of radiation, Wu said. This study’s findings point to the need for more research, he said.