Accuracy of computed tomographic colonography for the detection of polyps and colorectal tumors: a systematic review and meta-analysis.

BACKGROUND The real accuracy of computed tomographic colonography (CTC) is still unknown. OBJECTIVE To perform a meta-analysis of the diagnostic accuracy of CTC for the detection of polyps and colorectal tumors. METHODS SELECTION OF STUDIES Studiesassessing the accuracy of CTC for the detection of colorectal polyps and tumors were selected. data synthesis: Meta-analyses combining sensitivities, specificities and likelihood ratios (LRs) for the diagnosis of polyps and colorectal tumors were carried out. RESULTS Forty-seven studies, providing data of 10,546 patients, were included. Overall per-polyp sensitivity of CTC was 66% (64-68%), for polyps 6-9 mm in size it was 59% (56-61%), and 76% (73-79%) for polyps larger than 9 mm. Overall per-patient sensitivity was 69% (66-72%), for polyps 6-9 mm 60% (56-65%), and 83% (70-85%) for lesions larger than 9 mm. Overall CTC specificity was 83% (81-84%). Positive and negative LRs were 2.9 (1.8-4) and 0.38 (0.27-0.53), respectively; for polyps 6-9 mm in size, they were 3.8 (2.5-5.7) and 0.4 (0.27-0.59), and 12.3 (7.7-19.4) and 0.19 (0.12-0.3) for polyps larger than 9 mm. CONCLUSION CTC is highly specific for the detection of colorectal polyps and tumors. Some studies reported high sensitivities, but the results of the studies were highly heterogeneous, while the studied variables explained only part of this discrepancy.