Body imaging of all types has revolutionized the practice of medicine and saves countless lives every day. From the early use of x-rays for visualizing bones to the soft tissue CT and MRI scans that are common today, doctors are able to see and understand more so that they can do more.
Virtual colonoscopy (also known as CT colonography), a relatively newer use of CT scanning, is one such technique. It enables a radiologist to examine the colon for polyps that could become cancerous, thus potentially averting colon cancer.
In essence, it is a colon cancer screening technique that can be used as an alternative to traditional, optical colonoscopy, a technique that was first employed in 1969. This traditional technique has been perfected continually over those 40 years and remains the "gold standard" for colonoscopy. Optical colonoscopy (i.e. standard colonoscopy) is typically performed by a gastroenterologist who specializes in the digestive tract.
There are other tests that can determine the presence of colon cancer, but only a colonoscopy - virtual or standard - can spot polyps throughout the length of the colon before they become cancer.
If you are a candidate for a screening colonoscopy (the American College of Gastroenterology recommends screening for everyone at age 50; younger if a first degree relative has had colon cancer), should you have a standard colonoscopy or consider a virtual colonoscopy (also known as a CT colonography)?
Consider the following:
- All colon cancers start out as polyps
- Polyps can be removed during a standard colonoscopy but they cannot be removed during a virtual colonoscopy
- Removal of polyps is the only way to prevent colon cancer
- The National Cancer Society says it is not possible to identify which particular polyps will turn into cancers
If you are over 50 you have a 40 percent chance of having polyps. In other words, should you choose a virtual colonoscopy and you are in the 40 percent group, you will have to schedule a standard colonoscopy to have those polyps removed. This means scheduling an appointment with a gastroenterologist and repeating the colon cleansing process that is required with both procedures. Why go through the process twice? And why delay the removal of potentially cancerous polyps?
Virtual colonoscopy (CT colonography) uses radiation. This radiation exposure may increase your long term risk of developing cancer. Moreover, because of the uncertainty associated with virtual colonoscopy's ability to detect smaller polyps, more frequent follow up exams are recommended, compounding radiation risk. Standard colonoscopy involves no radiation.
After a thorough review of data, Medicare concluded that there was inadequate evidence to show that virtual colonoscopy is appropriate for colorectal screening. Likewise, the Colorado Clinical Guidelines Collaborative and the U.S. Preventive Services Task Force identify standard colonoscopy as the preferred colorectal screening method except in those limited circumstances where standard colonoscopy is not feasible.
Virtual colonoscopy is not covered by Medicare or most private insurance except in limited cases where optical colonoscopy is not feasible. Most insurance plans cover a straightforward screening standard colonoscopy if you meet the age and/or family history criteria outlined above. And, it will cover any follow-up colonoscopies based on your gastroenterologist's recommendation.
All of the Gastroenterology of the Rockies physicians are board certified gastroenterologists who received advanced training in performing standard colonoscopies and removing polyps. They perform hundreds of colonoscopies each year.
The need for a colonoscopy is real. In the United States, colorectal cancer (CRC) is the third most common cancer diagnosed among men and women. CRC largely can be prevented by the detection and removal of adenomatous polyps, and survival is significantly better when CRC is diagnosed while still localized. (Medical Position Statement of American Gastrological Association Institute).
The doctor gives you pain relievers and a sedative to bring you into a state called "conscious sedation." This is not like general anesthesia, where you’re unconscious, but a pleasant, sleepy, relaxed dreamlike state.
Colonoscopy is always done behind closed doors, in a private room, with no other patients around. Your privacy is a top concern.
Before the exam, your doctor administers pain relievers and a sedative through an intravenous (IV) line. The sedative brings you into a state called "conscious sedation." This is not like general anesthesia, where you’re unconscious, but a sleepy, relaxed dreamlike state.
After the procedure, you’ll be taken to one of our state-of-the-art recovery rooms where you’ll wake up. Most people feel OK after waking up. Some feel a bit woozy. You’ll be watched closely by one of our nurses. You may have some gas, which could cause mild discomfort and will be asked to pass gas. You will need someone to drive you home after receiving sedation.
The doctor will remove polyps because they could eventually become cancerous. If your doctor sees a large polyp or tumor or anything else abnormal, a biopsy will be done. For the biopsy, a small piece of tissue is removed. Having a biopsy is painless, because the inner lining of the colon has no pain receptor nerves.
Your doctor will suggest how often you need this exam, depending on your personal risk for colon cancer. Doctors usually recommended starting at age 50 and repeating it every 10 years. If you have an increased risk for colon cancer, or have had previous treatment for colon polyps or colorectal cancer, the test may be done at a younger age and more often. Find out from your doctor whether you should start before age 50.