Accuracy of routine nontargeted CT without colonography technique for the detection of large colorectal polyps and cancer

Dis Colon Rectum. 2010 Jun;53(6):911-8. doi: 10.1007/DCR.0b013e3181d5de13.

Abstract

Background: To assess the accuracy of routine contrast-enhanced computed tomography for the detection of large colorectal polyps and cancer.

Methods: The study group consisted of 100 patients who underwent abdominal computed tomography and optical colonoscopy evaluation before any treatment or intervention. Invasive colorectal carcinoma and large polyps (>or=10mm) were found at colonoscopy in 29 and 16 patients, respectively. Computed tomography studies with oral and IV contrast were retrospectively reviewed as 5-mm thick sections in standard soft tissue windows by 3 readers. The readers scored each segment for polyp or cancer utilizing a 5-point scale for receiver operating characteristic analysis.

Results: By-patient sensitivity/specificity for cancer detection for each reader was 69.0%/88.7%, 65.5%/84.5%, and 82.8%/77.5%, respectively. Pooled sensitivity, specificity, and accuracy for cancer was 72.4%, 83.6%, and 80.3%, respectively. The empiric area under the receiver operating characteristic curves for the readers ranged from 0.775 to 0.857. By-patient sensitivity for large polyps was poor with a pooled sensitivity of 14.5%.

Conclusions: Standard computed tomography not tailored to colorectal investigation was moderately effective for detecting invasive cancers, but insensitive for large polyps. Unsuspected cancer should be a part of the standard search pattern for routine computed tomography interpretation, but more advanced colonography techniques are necessary for detecting large polyps.

MeSH terms

  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma / pathology
  • Adult
  • Aged
  • Aged, 80 and over
  • Colonic Polyps / diagnostic imaging*
  • Colonic Polyps / pathology
  • Colonoscopy
  • Colorectal Neoplasms / diagnostic imaging*
  • Colorectal Neoplasms / pathology
  • Contrast Media
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Invasiveness / diagnostic imaging
  • Predictive Value of Tests
  • ROC Curve
  • Radiographic Image Interpretation, Computer-Assisted
  • Radiography, Abdominal
  • Retrospective Studies
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*

Substances

  • Contrast Media