Little Radiation Threat From 'Virtual Colonoscopy'
It uses CT scanning to visualize length of colon
FRIDAY, July 1, 2005 (HealthDay News) -- Radiation exposure from X-rays emitted during CT scans of the colon -- also called CT colonography or "virtual colonoscopy" -- does not significantly increase cancer risk, researchers report.
They estimated the increase in lifetime risk at less than 1 percent in the average 50-year-old recipient.
Researchers at the Center for Radiological Research at Columbia University Medical Center New York, said the radiation risk from virtual colonoscopy can be reduced further by creating optimized protocols for the use of this screening test.
Reporting in the July issue of Gastroenterology, the researchers estimated the radiation dose to different organs from adult CT colonography scans. They concluded that the estimated lifetime cancer risk as a result of CT colonography radiation is about 0.14 percent in a 50-year-old person and 0.022 in a 70-year-old person.
"Our study shows that radiation risks associated with virtual colonoscopy are relatively small -- much smaller, for example, than for CT-based lung cancer screening," study author David J. Brenner said in a prepared statement. Given its low risk, he described virtual colonoscopy as a very promising technology "which could potentially increase patient compliance with current guidelines for colorectal cancer screening."
"It's good news that the radiation risk is low with CT colonography, but many practical issues need to be addressed before the test can be recommended to patients for routine colorectal cancer screening," Dr. David A. Peura, president of the American Gastroenterological Association, added in a prepared statement.
"Evaluating issues of standardization and accuracy of test results and addressing disparities in consistent and uniform training of professionals performing the test should be the focus of future studies," Peura said. "In addition, the procedure still requires a great amount of bowel preparation and causes discomfort -- both issues that largely affect the current state of patient compliance in colorectal cancer screening."
The U.S. National Cancer Institute has more about colorectal cancer screening.