Computed tomography colonography: a retrospective analysis of outcomes of 2 years experience in a district general hospital

Abstract

Background: Colonoscopy is the gold-standard investigation for direct luminal visualization of the large bowel. Studies have shown the efficacy of computed tomography colonography (CTC) is equivalent to colonoscopy in both cancer and polyp detection. Methods: A retrospective review of patients undergoing CTC from January 2013 to October 2014 was performed. Patient demographics, indication for investigation, computed tomography findings, optical colonoscopy findings and histology results were recorded. Results: Seven hundred and fifty-eight CTC were performed. Three hundred and seventeen patients were male (42%) and 441 (58%) were female. Endoscopy was advised in 209 cases. One hundred and twenty (16%) were deemed suspicious for cancer of whom 96 (80%) had optical colonoscopy. A total of 12 colorectal cancers were detected. Potential polyps were noted in 58 cases (8%). Forty-four patients underwent endoscopy (75%) and 17 polyps confirmed (38%). Two patients had foci of invasive cancer histologically. Significant extracolonic findings were identified in 60%, including five cases of gastric carcinomas. The most common other findings were gallstones and hernias. Conclusion: The rate of colorectal cancer detection in this study was 2%. The rate of biopsy proven cancer was 10% following a suspicious colonogram. Endoscopic correlation was not obtained in 20% of cases of radiological suspicion. CTC is as efficacious as optical colonoscopy for colorectal cancer and polyp detection.

Optimal Strategies for Colorectal Cancer Screening

“…Virtual colonography uses a computed tomography (CT) scanner and computer reconstruction methods to visually evaluate the colon and rectum for colorectal polyps and cancers. For CRC screening, the recommended testing interval is 5 years, and individuals with abnormal findings must undergo traditional colonoscopy [23]. Sensitivity for adenomas 10mm or greater is 0.89 (95% CI, 0.83-0.96), and specificity is 0.94 (95% CI, 0.89-1.0) (Table 1)…”

“…The test results in clinically insignificant or indeterminate findings in 1.3-11.4% cases and potentially important findings in 3-4% of cases [1,3,4,18]. Lack of colonoscopic follow-up after abnormal CT colonography is also a notable clinical challenge as with other forms of non-colonoscopic screening [23].…”