title: Diagnostic accuracy of laxative-free computed tomographic colonography for detection of adenomatous polyps in asymptomatic adults: a prospective evaluation.
abstract: BACKGROUND
  Colon screening by optical colonoscopy (OC) or computed tomographic colonography (CTC) requires a laxative bowel preparation, which inhibits screening participation.
  
  
  OBJECTIVE
  To assess the performance of detecting adenomas 6 mm or larger and patient experience of laxative-free, computer-aided CTC.
  
  
  METHODS
  Prospective test comparison of laxative-free CTC and OC. The CTC included electronic cleansing and computer-aided detection. Optical colonoscopy examinations were initially blinded to CTC results, which were subsequently revealed during colonoscope withdrawal; this method permitted reexamination to resolve discrepant findings. Unblinded OC served as a reference standard. (ClinicalTrials.gov registration number: NCT01200303)
  
  
  METHODS
  Multicenter ambulatory imaging and endoscopy centers.
  
  
  METHODS
  605 adults aged 50 to 85 years at average to moderate risk for colon cancer.
  
  
  METHODS
  Per-patient sensitivity and specificity of CTC and first-pass OC for detecting adenomas at thresholds of 10 mm or greater, 8 mm or greater, and 6 mm or greater; per-lesion sensitivity and survey data describing patient experience with preparations and examinations.
  
  
  RESULTS
  For adenomas 10 mm or larger, per-patient sensitivity of CTC was 0.91 (95% CI, 0.71 to 0.99) and specificity was 0.85 (CI, 0.82 to 0.88); sensitivity of OC was 0.95 (CI, 0.77 to 1.00) and specificity was 0.89 (CI, 0.86 to 0.91). Sensitivity of CTC was 0.70 (CI, 0.53 to 0.83) for adenomas 8 mm or larger and 0.59 (CI, 0.47 to 0.70) for those 6 mm or larger; sensitivity of OC for adenomas 8 mm or larger was 0.88 (CI, 0.73 to 0.96) and 0.76 (CI, 0.64 to 0.85) for those 6 mm or larger. The specificity of OC at the threshold of 8 mm or larger was 0.91 and at 6 mm or larger was 0.94. Specificity for OC was greater than that for CTC, which was 0.86 at the threshold of 8 mm or larger and 0.88 at 6 mm or larger (P= 0.02). Reported participant experience for comfort and difficulty of examination preparation was better with CTC than OC.
  
  
  CONCLUSIONS
  There were 3 CTC readers. The survey instrument was not independently validated.
  
  
  CONCLUSIONS
  Computed tomographic colonography was accurate in detecting adenomas 10 mm or larger but less so for smaller lesions. Patient experience was better with laxative-free CTC. These results suggest a possible role for laxative-free CTC as an alternate screening method.
authors.affiliation: Department of Imaging, Massachusetts General Hospital, Suite 400A, 25 New Chardon Street, Boston, MA 02114, USA. mzalis@mgh.harvard.edu
authors.forename: Michael E
authors.initials: ME
authors.lastname: Zalis
authors.forename: Michael A
authors.initials: MA
authors.lastname: Blake
authors.forename: Wenli
authors.initials: W
authors.lastname: Cai
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hahn
authors.forename: Elkan F
authors.initials: EF
authors.lastname: Halpern
authors.forename: Imrana G
authors.initials: IG
authors.lastname: Kazam
authors.forename: Myles
authors.initials: M
authors.lastname: Keroack
authors.forename: Cordula
authors.initials: C
authors.lastname: Magee
authors.forename: Janne J
authors.initials: JJ
authors.lastname: Näppi
authors.forename: Rocio
authors.initials: R
authors.lastname: Perez-Johnston
authors.forename: John R
authors.initials: JR
authors.lastname: Saltzman
authors.forename: Abhinav
authors.initials: A
authors.lastname: Vij
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshida
mesh_terms: D018256:Adenomatous Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D023881:Colonography, Computed Tomographic / Q000009:adverse effects / Q000379:methods*; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D054368:Laxatives; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D054368:Laxatives