Minimally invasive test provides best alternative to colonoscopy

Research shows that a new scan offering patients a less invasive diagnostic test for possible bowel cancer is more effective than the current radiological standard of barium enema and should be considered alongside the 'gold standard' of colonoscopy.

Computed tomographic colonography is the name of the newer procedure. It is sometimes called 'virtual colonoscopy' because it uses a CT scanner and computer to generate 3D images of the colon.

However unlike colonoscopy, where a flexible endoscope is passed along the large bowel, CTC is minimally invasive and does not require sedation.

Despite the benefits of CTC the researchers urge caution. They state that guidelines are needed before CTC is used more widely because its ability to detect relatively unimportant findings can result in patients being referred for unnecessary follow-up tests.

In the first of the two trials published in The Lancet , more than 3,800 patients were given either a CTC or a barium enema. The research shows that CTC was more effective than barium enema at finding bowel cancers and precancerous polyps.

Professor Steve Halligan, joint-lead researcher on the study and Director of the University College of London (UCL) Centre for Medical Imaging, says, ''Our trial shows that CTC is more accurate than barium enema. We hope that barium enema will now be phased out in favour of CTC and that the National Institute for Health and Clinical Excellence will update its guidelines.