CTC Controversies (Radiation Exposure, Extracolonic Findings, Cost-Effectiveness)

CT colonography (CTC) is now in its mature stage. The technique has been consistently standardized [1], different multicenter trials [2–5] and meta-analysis [6] have confirmed the high accuracy in detecting cancer and significant polyps, CTC has completely replaced barium enema in many institutions worldwide, because of its superior diagnostic capability [7], and different indications for its use in current clinical practice have been defined with the agreement of gastroenterologists. CTC is now considered the method of choice to investigate the colon in cases of incomplete colonoscopy (OC) [8] and also in elderly and frail patients [9, 10], where the use of OC might be too risky. Moreover, according to the colorectal cancer (CRC) screening guidelines released in March 2008 by a multidisciplinary joint commission of the American Cancer Society, the US Multi-society Task Force on Colorectal Cancer (comprising three gastroenterology societies), and the American College of Radiology, CTC is also considered one of the preferred CRC screening tests for asymptomatic, average-risk individuals [11]. Unfortunately, especially when the discussion comes to the topic of CRC screening, the debate about the possible use of CTC remains. Other scientific entities, such as the US Preventive Services Task Force (USPSTF) [12], the Asia Pacific Working Group on Colorectal Cancer [13], and the American College of Gastroenterology [14], consider the evidence still insufficient to recommend CTC as a preferred CRC screening test and raise some concerns related to its potential harms. Those concerns were also at the basis of the 2009 decision of the Centers for Medicare and Medicaid (CMS) to not provide reimbursement for screening CTC [15].