Less-Invasive, Laxative-Free Virtual Colonoscopy as Accurate as Standard Methods

New UCSF research, performed jointly with Massachusetts General Hospital, confirms that computed tomographic colonography (CTC) administered without laxatives is as accurate as standard colonoscopy in detecting polyps that are clinically significant and potentially cancerous.

CTC, also known as virtual colonoscopy, uses a CT scanner for non-invasive screening, while conventional optical colonoscopy (OC) involves a physician inserting a six-foot long scope into the colon. Currently, both procedures require laxative induced bowel-cleansing prior to the exam. However, with laxative-free CTC, patients do not need to undergo bowel-cleansing, and, instead, must only begin a low fiber diet two days before the medical imaging exam. Additionally, patients must ingest a tagging agent that can be identified in the colon and removed digitally during radiologist scan interpretation.

Through this study, we have demonstrated that laxative-free CTC is a valid tool for detecting polyps that are clinically significant. The use of laxatives is often viewed as the worst aspect of having both a virtual colonoscopy and an optical colonoscopy. I hope that this research will encourage patients who have delayed screening for colon cancer to be examined with this less invasive method.

This study is one of the first and largest to measure this new, less invasive method, so look for additional studies to be conducted as the procedural development matures. I believe that once radiologists are trained in interpreting these new images, and as radiologists gain experience in the imaging exam process, laxative-free CTC exams will be available at widespread rate—likely, wherever virtual colonoscopies are performed.

For more information on this study, please see here.