Low-dose chest CT scans don't appear to damage human DNA, a new study shows.
The U.S.-based National Lung Screening Trial, conducted between 2002 and 2010 and involving more than 53,000 heavy and former smokers, revealed that these chest scans can significantly cut lung cancer deaths compared to chest X-rays. They do so by finding cancers at an earlier stage, researchers explained.
But with promise came worry.
"The National Lung Screening Trial suggested the value of low-dose CT screening in high-risk populations for developing lung cancer," explained study senior author Dr. Satoshi Tashiro, director of the Research Institute for Radiation Biology and Medicine at Hiroshima University in Japan.
"There were, however, no studies investigating the biological effect of low-dose CT scans on large numbers of patients. These findings led us to investigate these effects," Tashiro said.
His team looked for damage and abnormalities in chromosomes in 107 patients who underwent low-dose chest scans and 102 patients who underwent standard-dose chest scans. Significant differences were found in the two groups, according to the study published March 10 in the journal Radiology.
"We could clearly detect the increase of DNA damage and chromosome aberrations after standard chest CT," Tashiro said in a journal news release. "In contrast, no significant differences were observed in these biological effects before and after low-dose CT."
He believes this DNA analysis system could be applied to determining the side effects of other imaging techniques.
"We are interested in the biological effects of various types of radiological diagnosis, including PET/CT, to establish a better system for the management of medical radiation exposure," Tashiro said.
The American Lung Association has more on low-dose lung cancer screening.