Authors' objectives:

This review aims to assess the available evidence on computed tomographic colonography for detection of colorectal polyps and neoplasms

Authors' recommendations: With regard to CT Colonography (CTC) for the detection of colorectal polyps and neoplasms, the ICSI Technology Assessment Committee finds: CTC is a safe procedure with minor side effects reported. There is radiation exposure. The optional use of an intravenous and/or intraluminal contrast agent would potentially increase the morbidity and mortality risk. A single study with a screening population found good sensitivity and specificity for CTC compared with conventional colonoscopy when images were interpreted by trained radiologists who had read a minimum of 25 CTC studies. There were no significant differences between the sensitivities of CTC and conventional colonoscopy for the detection of adenomas 6 mm or larger or 10 mm or larger (all sensitivities approximately 90%). The specificity of CTC was 79.6% for adenomas 6 mm or larger and 79.6% for adenomas 10 mm or larger. The CTC procedure in this study included technical variations (i.e., use of 2 oral contrast agents, a multi-detector CT scanner, thin collimation, and a 3-dimensional "fly-through" analysis for primary review). It is unclear which, if any, of these variables contributed to the improved sensitivity of neoplasm detection. At present, this protocol is not uniformly used as many centers performing CTC do not have the required hardware or software. In a screening population, with the present data acquisition and interpretation protocols, it is unclear how CTC compares with conventional colonoscopy in terms of sensitivity and specificity due to limited available data. CTC is potentially useful for patients unwilling to undergo conventional colonoscopy or other procedures, who have failed conventional colonoscopy (incomplete examination of the colon), or who cannot be sedated. However, patients with positive findings on CTC (approximately 15% of the population) will require conventional colonoscopy to obtain biopsy specimens. CTC appears to be superior, in terms of detection of colorectal polyps and neoplasms, to no examination, fecal occult blood test, double-contrast barium enema, and flexible sigmoidoscopy. CTC has not been proven to be superior to conventional colonoscopy. Patient acceptance of CTC appears to be at least as good as acceptance of conventional colonoscopy. Due to variations in study protocols, it is unclear how sedation at conventional colonoscopy and bowel relaxants at CTC may affect patient ratings.

Authors' methods: Review

Project Status: Completed

URL for project: http://www.icsi.org/knowledge/detail.asp?catID=107&itemID=272

Year Published: 2004

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Institute for Clinical Systems Improvement

Contact Address: 8009 34th Avenue South, Suite 1200, Bloomington, MN, USA. Tel: +1 952 814 7060; Fax: +1 952 858 9675

Contact Name: icsi.info@icsi.org

Contact Email: icsi.info@icsi.org

Copyright: Institute for Clinical Systems Improvement (ICSI)