Advances in CT Colonography for Colorectal Cancer Screening and Diagnosis

Dept. of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94121, USA.
Journal of Cancer (Impact Factor: 3.27). 03/2013; 4(3):200-9. DOI: 10.7150/jca.5858
Source: PubMed


CT colonography (CTC) is a validated colorectal cancer test that provides an additional minimally-invasive screening option which is likely to be preferred by some patients. Important examination prerequisites include adequate colonic cleansing and distention. Tagging of residual material aids in the differentiation of true polyps from stool. Low radiation dose technique should be employed routinely for screening studies. Readers must be skilled in the use of both 2D and 3D interpretation methods.

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Available from: Rizwan Aslam, Jun 21, 2014

  • No preview · Article · Jan 2014 · coloproctology
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    ABSTRACT: Computed tomographic colonography (CTC) is a reliable option for screening of subjects who are unable or unwilling to undergo optical colonoscopy (OC). A colon capsule (PillCam Colon2®, CC2) has shown promising results in detecting polyps >6 mm. We compared the accuracies of CC2 and CTC in identifying individuals with at least 1 polyp >6 mm and subjects' attitude towards the procedures. Fifty individuals (mean age, 59.2±5.8 y; 58% male) with positive results from the immunochemical fecal occult blood test (iFOBT-positive) underwent CC2, CTC, and OC. The unblinded colonoscopy, integrating OC, CTC, and CC2 results were used as the reference standard. In a per-patient analysis, the accuracy of CC2 and CTC were assessed for individuals with at least 1 polyp ≥6 mm. Individuals were asked to choose which procedure they would be willing to repeat between CTC and CC2. The combination of OC, CTC, and CC2 identified 16 cases with at least 1 polyp ≥6 mm (reference standard). CTC identified the polyps with 88.2% sensitivity, 84.8% specificity, a 3.0 positive likelihood ratio, and a 0.07 negative likelihood ratio. CC2 identified the polyps with 88.2% sensitivity, 87.8% specificity, a 3.75 positive likelihood ratio, and a 0.06 negative likelihood ratio. Thirty-nine subjects (78%) said they preferred CC2 to CTC. CC2 and CTC detect polyps ≥6 mm with high levels of accuracy; these techniques are effective in selecting iFOBT-positive individuals who do not need to be referred for colonoscopy. CC2 seems to be better tolerated than CTC, and could be a reliable alternative to CTC for iFOBT-positive individuals who are unable or unwilling to undergo OC. Clinical number: NCT01744509.
    Full-text · Article · Jan 2014 · Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association
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    ABSTRACT: Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the Western world. The incidence could be reduced if this cancer were to be diagnosed at an early stage of disease. A competition has started between the existing screening methods to be the most efficient in detecting premalignant conditions. This review illustrates the current state of screening techniques for CRC. Pubmed was searched for meta-analyses and prospective studies on screening for CRC, with an emphasis on colonography, computed tomographic colonography (CTC), magnetic resonance colonography (MRC), stool DNA testing, and colon capsule endoscopy, and critical appraisal of the research was done by the reviewers. The imaging techniques (CTC and MRC) had similar detection rates for bigger lesions (≥10 mm) as colonoscopy. High-definition colonoscopy showed better efficiency with smaller lesions. The techniques developing around colonoscopy such as the retro-viewing colonoscope, the balloon colonoscope, or the 330-degree viewing colonoscope try to enhance efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy and the stool detection systems are limited to identifying cancer but not necessarily adenomas. Colonoscopy is the preferred CRC screening strategy and the undisputed gold standard in terms of efficacy.
    Preview · Article · Feb 2014 · Viszeralmedizin / Visceral Medicine
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