Diagnostic Performance of Double-contrast Barium Enema Comparing with Colonoscopy for Detecting Colorectal Cancer and Polyp in Nakornping Hospital

Background : Colonoscopy is the gold standard in colorectal tumor diagnosis whereas double-contrast barium enema (DCBE) is the basic tool to diagnose colorectal disease. There is no previous review about the results of both modalities in Nakornping Hospital. Objective : To determine the diagnostic performance of DCBE for detecting colorectal cancer and adenomatous polyp comparing with colonoscopy. Material and method : A cross-sectional diagnostic study was conducted in 141 patients whom suspicious with colorectal tumor and underwent both DCBE and colonoscopy in Nakornping Hospital between October 2006 and April 2011. Demographic and clinical data were retrospectively reviewed and analyzed with descriptive statistics. Diagnostic test analysis of DCBE was obtained by using colonoscopy as reference standard. Results : Mean age of the patients was 58.0 ± 12.5 years (range, 24-89) and 61.0% was female. All of 26 patients with colorectal cancer were diagnosed by both of DCBE and colonoscopy. DCBE could detect a larger number of patients with diverticulosis than colonoscopy (29 vs 17 cases). Colonoscopy was more accurate than DCBE for diagnosis of submucosal lesion and polyp (10 vs 4 cases and 8 vs 3 cases respectively), especially in small sized (<10 mm) polyp. Using colonoscopy as the gold standard for diagnosing colorectal cancer and polyp, DCBE had the sensitivity of 80.6%, specificity 99.1%, positive predictive value 96.7%, negative predictive value 93.7% and likelihood ratio for positive test of 84.6. Conclusion : The diagnostic performance of DCBE for detecting colorectal cancer and large sized (≥10 mm) polyp was comparable with colonoscopy. It might be used as a primary tool for diagnosis and screening of colorectal cancer in the hospital incapable with colonoscopy. Keywords : Double-contrast barium enema, Colonoscopy, Colorectal cancer