Role of preoperative CT colonography in patients with colorectal cancer

In patients with colorectal cancer(CRC),accurate preoperative evaluation is essential for a correct therapeutic plan.Colonoscopy and intravenous contrastenhanced computed tomography(CT)are currently recommended in the preoperative work-up for CRC.Preoperative colonoscopy has some limitations such as misdiagnosis of synchronous cancers in cases of incomplete exploration of the colon and inaccurate tumor localization.Intravenous contrast-enhanced CT successfully documents distant metastases although it sometimes enables unsatisfactory locoregional staging.Computed tomography colonography(CTC)is obtained after gas insufflation of the colon and offers a comprehensive preoperative evaluation in patients with CRC,including a definition of the segmental location of the tumor,presence of synchronous lesions or lack thereof,and fairly accurate locoregional staging.CTC has some limitations,including a lack of biopsy capability,suboptimal sensitivity for synchronous small polyps,and unsatisfactory nodal staging.Bearing in mind these limitations,CTC could be employed as a"one-stop-shop"examination for preoperative assessment in patients with CRC.