Detecting Colon Cancer with Virtual Colonoscopy Screening at Memorial Regional Hospital
Should You Have a Colonoscopy Screening?
Colorectal cancer often develops without symptoms. Although some people may have a stool specimen that tests positive for occult blood (microscopically determined). Men and women should be screened, starting at age 50. Approximately 90 percent of colorectal cancers occur in patients over 50 and the risk increases with age. For those with a family history of colon or other bowel diseases, an earlier screening is recommended.
July 2004 — Colorectal cancer is the third most common cancer found in men and women in the United States. The American Cancer Society estimates that in 2004, 56,730 people will die from colorectal cancer.
As daunting as the statistics may seem, these numbers can be reduced. Regular screenings can detect small growths in the colon, called polyps. With early detection and removal of polyps, the risk of colon cancer is dramatically decreased.
Physicians now have the option of using virtual colonoscopy, a less invasive and more comfortable screening method for early detection of this potentially life-threatening disease.
Traditional Screening
Current methods used to detect polyps include conventional colonoscopy and the barium enema. With conventional colonoscopy, which can take up to an hour, patients must be sedated as a long, flexible tube with a miniature camera on its tip is inserted through the entire colon — up to 6 feet. The physician views the image of the colon in real time. The total procedure time, including recovery, may take up to 8 hours.
A barium enema takes about 45 minutes and involves filling the colon with liquid barium, then taking X-rays. The barium coats the colon, which creates a more defined field for X-rays. The technician directs the patient to move into various positions to capture many angles of the colon. Patients must be sure to clear the colon of barium after the exam is complete to avoid constipation.
Whether it is because these procedures can be unpleasant or that people are unaware of the importance of regular screenings after the age of 50, individuals at the greatest risk of developing colorectal cancer tend to go unscreened.
Less Time, Less Discomfort
“With virtual colonoscopy, we use a computerized tomography (CT) scanner and virtual reality computer software to look inside the colon,” says Mark Schwimmer, MD, Chief of Radiology at Memorial Regional Hospital. “During the procedure, a small flexible rubber tube is placed in the rectum and air is introduced to distend the colon. A CT scan is performed while the patient lies comfortably on his or her back, then another scan is taken while the patient is on his or her stomach. The whole procedure takes only 10 to 20 minutes, and since there’s no sedation, patients can resume normal activity immediately after the screening. The CT data is then analyzed to detect colon polyps or cancers.”
While virtual colonoscopy is more agreeable to many patients, its accuracy is still being determined. “Many specialists may still rely on the real-time readings of conventional colonoscopy vs. virtual,” says Dr. Schwimmer. “However, virtual colonoscopy is 90 to 95 percent accurate in detecting polyps larger than 1 centimeter. Plus, it offers an alternative to those who would otherwise forego the screening altogether.”
Preparing for Virtual Colonoscopy
“Common questions include inquiries about how to prepare for a virtual colonoscopy and what kind of pain or discomfort to expect,” says Dr. Schwimmer. “For the most part, the preparation consists of a 24-hour liquid diet and the use of bowel-cleansing agents. Some patients experience minimal, temporary abdominal cramping during or after the screening, but this is typically mild.”
It important to remember, however, that the virtual method is a diagnostic tool used to help determine the presence of polyps. If a polyp is detected, conventional colonoscopy or surgery may be necessary to remove it.
If you are concerned about your risk of colorectal cancer, speak to your doctor. For referral to a physician, please call the Memorial Physician Referral Service at
(800) 944-DOCS.