Screening of postcolectomy patients: virtual colonography

Background: Virtual colonography (VC) is a powerful new method of imaging the entire colon, useful in polyps and colon cancer diagnosis. Aim: The aim of our study is to evaluate virtual colonography in the screening of colon cancer patients postoperatively. Methods: Fifty-three patients were examined with virtual colonography, 12–48 months postoperatively. Fortyfour patients had received segmental colectomy with restoration of the gastrointestinal tract, while nine patients abdominoperineal resection and permanent colostomy. Spiral CT examination of the abdomen with slice thickness 5 mm, (TS: 10 mm, RI: 2.5 mm), after proper cleansing of the colon and distention with air, performed in both supine and prone positions (including intravenous contrast medium injection). The images obtained were transferred to a separate workstation (Philips Easy Vision) for post processing, three-dimensional rendering and endoluminal viewing. Results: Eleven recurrences (16.41%) were identified in ten patients by virtual colonography, while one recurrence was missed. Conventional colonoscopy (cc) failed to complete in six cases, whereas two patients with colostomy refused colonoscopy. In all these eight cases (15%) VC was completed without problems. A second tumor in a patient who had received abdominoperineal resection was revealed by virtual colonography, while conventional colonoscopy failed to demonstrate the lesion. Liver metastasis identified in only one patient. Conclusions: VC seems to provide a good alternative in the follow-up of the post colectomy patients. The technique is effective in the diagnosis of locoregional recurrences and distant metastases, is well accepted by the patients and the results are equal to those of the conventional colonoscopy.