Fay Kastrinos, MD, MPH; Benjamin Lebwohl, MD; Alfred I. Neugut, MD, PhD
How accurate is computed tomographic colonography (CTC) for detecting colorectal cancer and adenomas ≥ 10 mm in diameter in asymptomatic adults?
Blinded comparison of CTC with optical colonoscopy and histologic review.
15 clinical centers in the USA.
2600 asymptomatic adults ≥ 50 years of age (mean age 58 y, 52% women, based on 2531 adults with complete data) who were scheduled to have routine colonoscopy. Exclusion criteria were ≥ 1 occurrence of melena or hematochezia in the past 6 months, lower abdominal pain, inflammatory bowel disease, the familial polyposis syndrome, anemia (hemoglobin < 6.2 mmol/L [10 g/dL]), positive fecal occult blood test, serious medical conditions associated with increased risk for colonoscopy complications, and colonoscopy within the past 5 years.
CTC using multidetector row CT scanners with ≥ 16 rows. After stool and fluid tagging, laxative purgation, colonic insufflation (mechanical or manual), and subcutaneous glucagon, participants were examined in supine and prone positions. Lesions ≥ 5 mm in diameter were considered a positive result.
Optical colonoscopy performed according to protocols of individual centers, with central histologic review for lesions ≥ 5 mm. Adenomas were defined as polyps with aberrant proliferation or cytologic dysplasia of the epithelium at the luminal surface and to any depth.
Included sensitivity and specificity averaged across 15 participating radiologists.
11% of participants had colorectal adenomas or cancer ≥ 5 mm in diameter; 4% had large lesions (≥ 10 mm). Per-patient diagnostic characteristics of CTC for adenomas or cancer are shown in the Table. 547 lesions ≥ 5 mm, including nonadenomatous types, were found in 390 participants and were located in the sigmoid (27%), ascending colon (18%), transverse colon (17%), rectum (16%), descending colon (11%), and cecum (11%). 68% of lesions were adenomas or cancer. Per-lesion sensitivity of CTC for adenomas or cancer was 59% for lesions ≥ 5 mm and 84% for those ≥ 10 mm.
Computed tomographic colonography had 90% sensitivity and 86% specificity for diagnosing large colorectal adenomas or cancer in asymptomatic adults.
Computed tomographic colonography compared with colonoscopy and histologic review for diagnosing colorectal adenomas or cancer in asymptomatic adults*
*Diagnostic terms defined in Glossary. +LR and −LR calculated from data in article.
Kastrinos F, Lebwohl B, Neugut AI. CT colonography had 90% sensitivity and 86% specificity for diagnosing large adenomas and cancer in asymptomatic adults. Ann Intern Med. ;150:JC2–13. doi: 10.7326/0003-4819-150-4-200902170-02013
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Published: Ann Intern Med. 2009;150(4):JC2-13.
Colonoscopy/Sigmoidoscopy, Gastroenterology/Hepatology, Hematology/Oncology.
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Print ISSN: 0003-4819 | Online ISSN: 1539-3704
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