Post-surgical follow-up of colorectal cancer: role of contrast-enhanced CT colonography

To evaluate the role of CT colonography (CTC) in the follow-up of patients having received partial colectomy for colorectal cancer. CTC was performed in 72 subjects with history of partial colectomy for colorectal cancer. Colectomy had been performed in the right colon (n = 18), descending colon (n = 15), sigmoid colon (n = 21), and rectum (n = 18). Patients underwent CTC following incomplete conventional colonoscopy due to intolerance to endoscope insertion or luminal stenosis. In 70 cases pneumocolon was obtained through a rectal tube, and in 2 cases through a cutaneous anastomosis. CTC datasets were analyzed in combined 2D and 3D mode. All patients in whom CTC was suggestive for or raised the suspicion of disease recurrence underwent colonoscopy in sedation for confirmation of CTC findings. CTC detected 7 cases of anastomotic stenosis. In 6/7 patients the stenosis was located in the sigmoid colon and in 1/7 patients at the level of the ileo-colic junction in the transverse colon. Out of these cases, four were fibrotic and three were neoplastic stenoses. In none of these cases was the CT appearance of the stenoses specific for disease recurrence, and conventional colonoscopy together with biopsy was necessary in order to characterize such findings. However, sensitivity of CTC in detecting anastomotic stenosis was 100% (7/7). One colonic mass (5 cm largest diameter) was detected in one case at the level of the proximal transverse colon in a patient with left colectomy performed 2 years before. The study of the residual colon showed 3 polyps in three patients (8, 6, and 5 mm, respectively). All CT findings were confirmed and characterized by conventional colonoscopy. In all cases the residual colon was entirely visualized by CTC with a completion rate of 100%. CTC is a feasible and minimally invasive method for full exploration of the colon after surgical resection allowing detection of cancer recurrence, metachronous disease, and distant metastases in one single study, and represents a valid alternative to conventional colonoscopy in this patient population.