Virtual Colonoscopy Could Increase Screening, Save Lives
Colorectal cancer -- cancer of the colon or rectum -- is the second-leading cause of cancer-related death in the U.S., trailing only lung cancer. More than 150,000 new cases of colorectal cancer will be diagnosed this year, and the disease will lead to approximately 55,000 deaths.
This form of cancer is highly curable with early detection and screening. However, because the traditional method of screening -- optic colonoscopy with a scope -- can often be painful and time-consuming, less than a third of the at-risk population (anyone over age 50) are regularly screened.
Now physicians have CT colonography (popularly known as virtual colonoscopy), a much less invasive screening method, to help in the fight against this killer disease. The procedure uses CT (computed tomography) scans to look at the colon. These scans are converted into 3-D images to provide a detailed look at the entire colorectal region.
Kirk Ludwig, M.D., chief of gastrointestinal surgery at Duke University Medical Center, says the new test could help reduce the threat of colon cancer for millions of men and women.
"Perhaps a method of screening that's less invasive, less time-consuming and makes less of an impact on patients' lives will encourage people to seek screening so that more cancers can be prevented," Ludwig says. "Early detection is key to not only preventing colorectal cancer, but to initiating treatment when the cancer is at an early stage, which is when treatment is most effective."
Erik Paulson, M.D., chief of abdominal imaging at Duke, adds that the newer screening method offers several benefits.
"Patients undergo the same type of preparation as for an optic colonoscopy," he says. "The difference is that we then take a CT scan of the colon and ship these images to a workstation where we can look at the colon wall for polyps.
"Most protocols require that a CT scan be performed once with the patient on his or her back and once lying on the stomach. Each CT scan takes between 20 and 25 seconds. The patient is usually in the room for the scan for eight to 10 minutes, total. No sedation, no intravenous line and no monitoring of vital signs are necessary. When the procedure is completed, you can return to work and your normal schedule."
Paulson points out, however, that at the current time there are two drawbacks to virtual colonoscopy, one medical and one economic. First, people should realize that if a polyp is detected using CT colonography, it is then necessary to have a traditional optic colonoscopy in order to have the polyp removed. Second, CT colonography screening is not currently covered by most insurance plans.
"I think it will be," he adds, "but we're probably three years away."