The National CT Colonography Trial (ACRIN6664)

The National CT Colonography Trial: Multicenter Assessment of Accuracy for Detection of Large Adenomas and Cancers in a Healthy Screening Population

RATIONALE: New diagnostic procedures such as computed tomographic colonography may improve the ability to detect colorectal cancer and may provide a less invasive method of detection. PURPOSE: This clinical trial is studying how well computed tomographic colonography works in screening healthy participants for colorectal cancer.

OBJECTIVES: Primary Compare the sensitivity of computed tomographic colonography (CTC) vs colonoscopy for detecting significantly large lesions (≥ 10 mm in diameter) in asymptomatic participants, in terms of specificity, area under the ROC curve, and predictive values for detecting clinically significant colorectal neoplasia. Secondary Determine the interobserver variation in accuracy of interpreting CTC examinations of these participants, including any benefits of a primary 3-dimensional read and/or independent second interpretations. Determine the effects of different colon preparations on the accuracy of CTC in these participants. Compare participant acceptance and willingness to have a repeat examination by CTC vs colonoscopy. Determine the accuracy of CTC in detecting flat lesions in the colon of these participants. OUTLINE: This is a multicenter study. Participants receive an oral laxative, oral bisacodyl, and three doses of oral barium sulphate 24 hours before imaging. After cathartic cleansing, participants undergo computed tomographic colonography followed by colonoscopy. Participants are followed up for approximately 4 weeks. PROJECTED ACCRUAL: A total of 2,607 participants will be accrued for this study.

CT colonography performed for comparison with colonoscopy results performed during the same screening assessment.

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=10mm (as measured at pathology) RS-: No Advanced adenomas >=10mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=9mm (as measured at pathology) RS-: No Advanced adenomas >=9mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=8mm (as measured at pathology) RS-: No Advanced adenomas >=8mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=7mm (as measured at pathology) RS-: No Advanced adenomas >=7mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=6mm (as measured at pathology) RS-: No Advanced adenomas >=16mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard (RS) for determining the existence of advanced adenomas. RS+: Colonoscopy found at least 1 Advanced adenomas >=5mm (as measured at pathology) RS-: No Advanced adenomas >=5mm found by colonoscopy (as measured at pathology)

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Pathology results from Colonoscopy performed up to 30 days after a CTC examination were used as the reference standard for determining the existence of advanced adenomas. CTC lesions needed to be within 2 segments and 50% size of the lesions removed via colonoscopy to be considered "detected"

Evaluate interobserver variability in Sensitivity (P(T+|D+)) and 95% CI) when interpreting CTC examinations Each study was randomly assigned to be read independently using either a primary 2D search method (conventional 2D image display with 3D endoluminal problem solving), or a primary 3D search method (including the capability of displaying multiplanar 2D) and without prior knowledge of the colonoscopy results. A second trained radiologist of similar skill was assigned to read the images using the other modality Readers were then classified as high performing or not high performing

Inclusion Criteria Male or female outpatients Aged 50 years or older Scheduled for screening colonoscopy Participant's signed informed consent Exclusion Criteria Symptoms of disease of the lower gastrointestinal tract, including Melanotic stools or/and hematochezia on more than one occasion in the previous six months Lower abdominal pain that would normally require a medical evaluation Inflammatory bowel disease and/or familial polyposis syndrome Serious medical conditions that would increase the risk associated with colonoscopy or are so severe that screening would have no benefit Pregnancy Previous colonoscopy within the past five years Anemia (hemoglobin less than 10 gm/dl) Positive fecal occult blood test (FOBT)

Researchers may request data from the ACRIN data access committee by reviewing the information at: https://www.acrin.org/RESEARCHERS/POLICIES/DATAANDIMAGESHARINGPOLICY.aspx

Vanness DJ, Knudsen AB, Lansdorp-Vogelaar I, Rutter CM, Gareen IF, Herman BA, Kuntz KM, Zauber AG, van Ballegooijen M, Feuer EJ, Chen MH, Johnson CD. Comparative economic evaluation of data from the ACRIN National CT Colonography Trial with three cancer intervention and surveillance modeling network microsimulations. Radiology. 2011 Nov;261(2):487-98. doi: 10.1148/radiol.11102411. Epub 2011 Aug 3.

Johnson CD, Herman BA, Chen MH, Toledano AY, Heiken JP, Dachman AH, Kuo MD, Menias CO, Siewert B, Cheema JI, Obregon R, Fidler JL, Zimmerman P, Horton KM, Coakley KJ, Iyer RB, Hara AK, Halvorsen RA Jr, Casola G, Yee J, Blevins M, Burgart LJ, Limburg PJ, Gatsonis CA. The National CT Colonography Trial: assessment of accuracy in participants 65 years of age and older. Radiology. 2012 May;263(2):401-8. doi: 10.1148/radiol.12102177. Epub 2012 Feb 23.

Hara AK, Blevins M, Chen MH, Dachman AH, Kuo MD, Menias CO, Siewert B, Cheema JI, Obregon RG, Fidler JL, Zimmerman P, Horton KM, Coakley KJ, Iyer RB, Halvorsen RA Jr, Casola G, Yee J, Herman BA, Johnson CD. ACRIN CT colonography trial: does reader's preference for primary two-dimensional versus primary three-dimensional interpretation affect performance? Radiology. 2011 May;259(2):435-41. doi: 10.1148/radiol.11100250. Epub 2011 Mar 1.

Hara AK, Kuo MD, Blevins M, Chen MH, Yee J, Dachman A, Menias CO, Siewert B, Cheema JI, Obregon RG, Fidler JL, Zimmerman P, Horton KM, Coakley K, Iyer RB, Halvorsen RA Jr, Casola G, Johnson CD. National CT colonography trial (ACRIN 6664): comparison of three full-laxative bowel preparations in more than 2500 average-risk patients. AJR Am J Roentgenol. 2011 May;196(5):1076-82. doi: 10.2214/AJR.10.4334.

Siewert B, Gareen I, Vanness D, et al.: ACRIN 6664: patient acceptance and preferance of CT colonography compared to optical colonoscopy for colon cancer screening. [Abstract] J Clin Oncol 27 (Suppl 15): A-4034, 2009.

Johnson CD, Chen MH, Toledano AY, Heiken JP, Dachman A, Kuo MD, Menias CO, Siewert B, Cheema JI, Obregon RG, Fidler JL, Zimmerman P, Horton KM, Coakley K, Iyer RB, Hara AK, Halvorsen RA Jr, Casola G, Yee J, Herman BA, Burgart LJ, Limburg PJ. Accuracy of CT colonography for detection of large adenomas and cancers. N Engl J Med. 2008 Sep 18;359(12):1207-17. doi: 10.1056/NEJMoa0800996. Erratum In: N Engl J Med. 2008 Dec 25;359(26):2853.