Virtual CT scan – The Best Alternative To colonoscopy
According to a study recently published in the Lancet, a new method to investigate colon cancer is CT colonography (CTC) or virtual colonoscopy. Unlike other imaging method of investigating diseases of the colon, like traditional X-ray test of barium enema, CTC is less invasive and provides more detailed and more accurate information.
Researchers made two trials in which were included more than 3,800 patients that were investigated either by barium enema or by CTC. The result of the study was that CTC is more effective in detecting precancerous polyps or colon cancer. Colon cancer is one of the most common malignancies of the digestive system and, what is important, is that it is one of the cancers that can be successfully cured if detected early.
Colonoscopy with biopsy is currently the gold standard for colon cancer diagnosis. This investigation involves endoscopic examination using a fiber optic camera and thus offers the opportunity to view any lesion at the inside of the colon. Unlike barium enema, colonoscopy is more accurate because it offers the possibility of biopsy. In addition, there is the possibility of polyp resection which greatly decreases postoperative morbidity and complications that could occur after a colon surgery. Unlike colonoscopy, CTC is a method of imaging that uses X-rays to build a virtual three-dimensional image of the inside of the bowel.
Professor Steve Halligan, based at UCL and joint lead researcher, said that their study shows that CTC is more accurate than barium enema. But for the CTC to become basic investigation in the diagnosis of colon cancer, clinics must have, in addition to CT scans, specialized radiologists in CTC.”These radiologists will need training in order to deliver the results we observed in our trials “, added Dr. Halligan.
The other study was conducted on 1,600 patients and the aim was to see which of the two investigations, CTC or colonoscopy, is more effective. Studies so far have shown that the two investigations have similar sensitivity in detecting colon cancer. Unlike colonoscopy, CTC has a disadvantage because it does not offer the possibility of biopsy and thus one cannot tell if the lesions are benign or malignant. Professor Wendy Atkin, based at Imperial College London and joint lead researcher, says that CTC detects unimportant lesions this is why guidelines are necessary to help doctors decide which patients will need further testing. He added that CTC is a viable option for patients who, for whatever reason, do not want to have a colonoscopy.