title: CT colonography: performance and program outcome measures in an older screening population.
abstract: OBJECTIVE
  To evaluate computed tomographic (CT) colonography performance and program outcome measures in an older cohort (65-79 years) of an established large-scale colorectal cancer screening program.
  
  
  METHODS
  This HIPAA-compliant study was approved by the institutional review board; informed consent waived. Retrospective analysis of the 65-79-year-old cohort (n = 577) from the University of Wisconsin CT colonography screening program (n = 5176) was undertaken. Performance and outcome measures including advanced neoplasia prevalence and colonoscopy referral, extracolonic finding, extracolonic work-up, and complication rates were obtained by using a CT colonography database and review of medical records. Comparisons between the older cohort and the general screening population were made by using the Student t, Pearson chi(2), and Fisher exact tests. A P value <or= .05 was considered to indicate a significant difference.
  
  
  RESULTS
  With a 6-mm threshold for positivity, the overall referral rate to optical colonoscopy was 15.3% (88 of 577), leading to 277 polypectomies and the removal of 103 nondiminutive adenomas. For adenomas, the per-patient positivity rates were 10.9% (63 of 577) and 6.8% (39 of 577) at the 6- and 10-mm thresholds, respectively. The prevalence of advanced neoplasia was 7.6% (44 of 577). Fifty-four adenomas met advanced status, and five unsuspected cancers were detected. The advanced neoplasias identified were typically large, with a mean size of 21 mm. Potentially important extracolonic findings were seen in 15.4% (89 of 577) of patients, with a work-up rate of 7.8% (45 of 577). The majority of important extracolonic diagnoses were vascular aneurysms (n = 18). No major complications were encountered.
  
  
  CONCLUSIONS
  CT colonography is a safe and effective screening modality for the older population.
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Science Center, 600 Highland Ave, Madison, WI 53792-3252, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Kim
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Pickhardt
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Hanson
authors.forename: J Louis
authors.initials: JL
authors.lastname: Hinshaw
mesh_terms: D000367:Age Factors; D000368:Aged; D000465:Algorithms; D016009:Chi-Square Distribution; D023881:Colonography, Computed Tomographic / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D015995:Prevalence; D011857:Radiographic Image Interpretation, Computer-Assisted; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D014922:Wisconsin / Q000453:epidemiology