Coming soon non-invasive virtual colonoscopy Each year more than 50,000 people die of colorectal cancer, making it second only to lung cancer in cancer deaths each year. Yet it is highly preventable through a healthy lifestyle and regular screening. If detected early, colon cancer is 90 percent curable. Virtual Colonoscopy is a promising new method for detecting colorectal polyps and cancers. Polyps are small growths in the colon that may become cancerous if they are not removed. Virtual Colonoscopy is a recently developed technique that uses a CT scanner and computer virtual reality software to look inside the body without having to insert a long tube (Conventional Colonoscopy) into the colon or without having to fill the colon with liquid barium (Barium Enema). Research shows that Virtual Colonoscopy is better able to see polyps than a Barium Enema and is nearly as accurate as Conventional Colonoscopy. In addition, most patients report that Virtual Colonoscopy is more comfortable than other exams. Procedure Virtual Colonoscopy uses a high-speed multi-slice computed tomography (CT) scan of the abdomen, which allows radiologists (special physicians with advanced training in x-ray imaging) to create pictures on the computer that look similar to those seen by Conventional Colonoscopy. Patients need a cleansing preparation of their bowel prior to the test. The day of the test, they come to the radiology department for a CT scan. The actual Virtual Colonoscopy procedure will begin by having a small flexible rubber tube placed in the rectum, so that air can be introduced. A CT scan is then performed while patients lie comfortably on their back and then on their stomach. The total time required for the study is approximately 10-20 minutes. Because sedation is not required, patients are free to leave the CT suite immediately without the need for observation or recovery. Patients can resume normal activities immediately after the procedure and can eat, work, or drive without a delay. Doctors (radiologists) analyze the CT data to detect colon polyps or cancers. When air is introduced in the colon some patients experience minimal temporary abdominal cramping or "gas pains." An intravenous injection of a widely used medicine to relax the bowel can also be given to help reduce gas pains, but this is usually not necessary. Accuracy Studies suggest a very high sensitivity and specificity (96 percent) for the detection of polyps, 1 cm. or greater. Such polyps have significant malignant potential. Sensitivity for polyps less than 10 mm. is significantly less. Although controversy exists as to the definition of a "significant" polyp with regard to size, polyps less than 1 cm in size have a low probability of malignancy and the likelihood of any single lesion progressing to cancer is also small. Advantages Virtual Colonoscopy is minimally invasive, and does not carry the low but real (1 in 1500) risk of perforation associated with Conventional Colonoscopy. It is well tolerated by patients and does not require sedation. It is capable of evaluating the colon upstream from obstructing lesions that may prevent passage of an endoscope. Virtual Colonoscopy is significantly less expensive than Conventional Colonoscopy. As with any procedure, there are no guarantees that all clinically significant growths will be detected. It should be remembered that between 10 and 20 percent of all polyps and up to five percent of colon cancers are missed, even on Conventional Colonoscopy. Virtual Colonoscopy (like the Barium Enema) is a diagnostic, not therapeutic, technique. All patients in whom polyps are identified would need to undergo Conventional Colonoscopy for removal. Return to Newsletter