New Ways to Diagnose Colon Cancer
New advances in colonoscopy promise faster and easier screenings.
The Virtual Test continued...
"For the most part, when a patient leaves here they are pleased and happy.
They are on and off the table in no time, and there is no sedation. You can
literally go back to work in 10 minutes," says Michael Macari, director of
abdominal imaging at NYU Medical Center in New York City.
Besides the fact that the screening is noninvasive, Marcari says that prior
to the test his center also uses carbon dioxide -- compared with "room air" --
to extend the colon. The difference, he says, means very little cramping and
almost no residual pain after the screening is completed.
"Initially there is a little pressure but the carbon dioxide gets absorbed
so fast, by the time they leave they feel fine," says Macari.
Looking to the Future
While the screening itself may be fast and easy, right now it requires the
same preparation as the regular colonoscopy, so patients are not spared the
However, Macari reports that may change in the not-too-distant future, with
the advent of a process called "fecal tagging."
In this procedure, he says, patients drink an agent which -- once inside the
colon -- latches onto the fecal material and helps doctors differentiate
between that and polyps on the scan.
"We just completed study of 80 patients using fecal tagging and no bowel
cleansing and we had a very high rate of detection of polyps over 10
millimeters, which many believe is the real threshold for removal," says
In another study published in the journal Radiology doctors from
Belgium compared fecal tagging with standard colonoscopy preparation. They
found that fecal tagging left behind more fecal residue, but improved
differentiation of polyps. The fecal tagging also dramatically reduced patient
discomfort, side effects, and sleep disturbances.
Still, Marcari says he would not routinely recommend it for virtual
colonoscopy -- at least not until larger studies are done.
"Right now it's used if a patient simply cannot tolerate the standard prep,
or if a medical condition precludes them from participating in the standard
prep," says Macaria.
As easy as a virtual colonoscopy appears to be, Brooks cautions that should
a polyp be found during the exam, the patient must still undergo a standard
colonoscopy to have the growth removed.