One of the discussions at GI Symposium was whether virtual colonoscopy is ready for prime time. What is that? Well, it is a CT scan which evaluates the colon for polyps and other changes instead of using a scope to enter the colon and look directly.
It is often misunderstood that the preparation for these two procedures are different. They are not. You need a clean colon whether you get a CT colonoscopy or a real one.
The question is: are the two procedures equivalent? For lesions larger than 10 millimeters it seems that virtual colonoscopies look very similar to colonoscopies without the discomfort of the scope.
For a colonoscopy you need someone to drive you home, and you are usually out of work for one day. In contrast, with a virtual colonoscopy, you can drive yourself and you can go back to work. (Sometimes that is not what you may want). Interestingly, the presenter said that the virtual colonoscopy has a little bit more discomfort because they don’t use anesthesia, and some patients did not like that. But, in most studies patients preferred the virtual colonoscopy.
One of the advantages with the virtual colonoscopy is that more people may consider getting screened with it. It is astonishing that 35 million Americans should be screened and are not. This technology may convince some of them.
The disadvantage is that if the virtual colonoscopy finds something, you need a colonoscopy. If the hospital is not set up to do it right away, you have to do the bowel prep all over. This happens in about 10% of all cases. If the virtual colonoscopy finds a polyp or something suspicious, a gastroenterologist needs to go in and biopsy or remove it.
Another disadvantage is that virtual colonoscopy may not be able to detect polyps smaller than 6 millimeters. The recent publication showing that flat lesions may be much more important to detect and remove raises another concern that virtual colonoscopy may not be able to pick these up.
In the most recent literature it was reported that colon cancer on the right side are much more often overlooked during colonoscopy than previously reported in addition to flat lesions. This brings the quality of colonoscopy back into focus. The skill of the gastroenterologist will guarantee the success of the colonoscopy.
The GI Symposium is the only way that oncologists, surgeons, radiologists and gastroenterologists can address all these concerns. In the coming years we will find out how really important flat lesions are and whether virtual colonoscopy can replace the colonoscopy.