Accuracy of CT colonography for detection of large adenomas and cancers.
BACKGROUND
Computed tomographic (CT) colonography is a noninvasive option in screening for colorectal cancer. However, its accuracy as a screening tool in asymptomatic adults has not been well defined.


METHODS
We recruited 2600 asymptomatic study participants, 50 years of age or older, at 15 study centers. CT colonographic images were acquired with the use of standard bowel preparation, stool and fluid tagging, mechanical insufflation, and multidetector-row CT scanners (with 16 or more rows). Radiologists trained in CT colonography reported all lesions measuring 5 mm or more in diameter. Optical colonoscopy and histologic review were performed according to established clinical protocols at each center and served as the reference standard. The primary end point was detection by CT colonography of histologically confirmed large adenomas and adenocarcinomas (10 mm in diameter or larger) that had been detected by colonoscopy; detection of smaller colorectal lesions (6 to 9 mm in diameter) was also evaluated.


RESULTS
Complete data were available for 2531 participants (97%). For large adenomas and cancers, the mean (+/-SE) per-patient estimates of the sensitivity, specificity, positive and negative predictive values, and area under the receiver-operating-characteristic curve for CT colonography were 0.90+/-0.03, 0.86+/-0.02, 0.23+/-0.02, 0.99+/-<0.01, and 0.89+/-0.02, respectively. The sensitivity of 0.90 (i.e., 90%) indicates that CT colonography failed to detect a lesion measuring 10 mm or more in diameter in 10% of patients. The per-polyp sensitivity for large adenomas or cancers was 0.84+/-0.04. The per-patient sensitivity for detecting adenomas that were 6 mm or more in diameter was 0.78.


CONCLUSIONS
In this study of asymptomatic adults, CT colonographic screening identified 90% of subjects with adenomas or cancers measuring 10 mm or more in diameter. These findings augment published data on the role of CT colonography in screening patients with an average risk of colorectal cancer. (ClinicalTrials.gov number, NCT00084929; American College of Radiology Imaging Network [ACRIN] number, 6664.)
Johnson
C Daniel
CD
Mayo Clinic Arizona, Scottsdale, AZ, USA.
Chen
Mei-Hsiu
MH
Toledano
Alicia Y
AY
Heiken
Jay P
JP
Dachman
Abraham
A
Kuo
Mark D
MD
Menias
Christine O
CO
Siewert
Betina
B
Cheema
Jugesh I
JI
Obregon
Richard G
RG
Fidler
Jeff L
JL
Zimmerman
Peter
P
Horton
Karen M
KM
Coakley
Kevin
K
Iyer
Revathy B
RB
Hara
Amy K
AK
Halvorsen
Robert A
RA
Casola
Giovanna
G
Yee
Judy
J
Herman
Benjamin A
BA
Burgart
Lawrence J
LJ
Limburg
Paul J
PJ
D000230:Adenocarcinoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D000236:Adenoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D000368:Aged; D003106:Colon / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
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