Optimisation and Performance of Reduced Preparation CT Colography

Multidetector-row CT Colonography: Optimisation of Reduced Bowel Preparation Regimes and Diagnostic Performance in Comparison to Colonoscopy

To ascertain which of four combinations of low residue diet, reduced laxative dose and oral contrast agent is best tolerated by patients and optimally prepares the colon prior ro CT colonography

Study Overview

• Status: Completed
• Conditions: Patients With Potential Colorectal Neoplasia
• Intervention / Treatment: Drug: Tagitol V, Lo So, Readi-Cat 2

Detailed Description

CT colonography has been shown to be accurate in detection of colorectal neoplasia in enriched patient populations and is generally preferred by patients to conventional endoscopy and barium enema. It is advocated as an acceptable alternative for colorectal cancer screening and is increasingly used in the investigation of symptomatic patients. Ideally, like conventional colonoscopy, CT colonography requires a clean colon, free of residual stool and fluid. There is however good evidence that the arduous bowel purgation regimes required may produce adverse effects such as electrolyte imbalance, and are more detrimental to overall patient experience and compliance than any subsequent investigation. An ability to perform CT colonography with reduced bowel purgation, whilst maintaining acceptable diagnostic accuracy, would undoubtedly make the technique a more attractive proposition both for population screening and investigation of symptomatic patients.

Interest has been generated in the use of orally ingested dilute barium or ionated contrast medium prior ro CT colonography to "label" or "tag" residual fluid or faecal matter reduced laxative. Such oral contrast agents are highly attenuating to X-rays such that labeled residual bowel contents appear white on CT scanning and are readily distinguished from true colonic pathology.

Despite the early promise of a few limited studies, there is no consensus as to the optimum oral contrast type, dose and concentration. Anecdotally barium tends to best label solid residue whereas iodinated contrast best labels fluid, but this assumption has not been proven. Furthermore it is known that iodinated contrast tends to draw fluid into the bowel, producing a wet colon, which may not be suited to CT colonography. However, this indrawing of fluid by iodinated contrast such as gastrograffin produces a mild laxative effect, which may obviate the need for further formal purgation.

The study aims to establish the optimum reduced preparation-tagging regimen, establish patient experience and document diagnostic performance compared to conventional colonoscopy.

• Study Type: Interventional
• Enrollment: 120
• Phase: Phase 4

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, NW1 2BU
    • University College Hospital
  • Oxford, United Kingdom
    • Oxford Radcliffe Hospital NHS Trust
  • Middlesex
    • London, Middlesex, United Kingdom, HA1 3UJ
      • St Mark's Hospital, North West London Hospitals NHS Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients who are under investigation for suspected colonic neoplasia and over 50 years old:

  1. Symptomatic patients eg. change in bowel habit, rectal bleeding etc.
  2. Polyp surveillance
  3. Strong family history
  4. suspected neoplasia on previous investigation (e.g. barium enema)

Exclusion Criteria:

• patients under 50 patients undergoing surveillance for inflammatory bowel disease (due to poor diagnostic use of CT colonography in this specific patient cohort)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Which of four combinations of low residue diet, reduced laxative dose and oral contrast agent is best tolerated by patients and optimally prepares the colon prior ro CT colonography

Secondary Outcome Measures

Outcome Measure
to compare the diagnostic performance of CT colonography after reduced bowel preparation and faecal tagging with conventional colonoscopy in patients undergoing both procedures

Collaborators and Investigators

• Sponsor: London North West Healthcare NHS Trust
• Collaborators: St Mark's Foundation
• Investigators: Principal Investigator: Stuart Taylor, MD, St Mark's Hospital, North West London NHS Trust; & University College Hospital

Study record dates

Study Major Dates

• Study Start: July 1, 2004
• Study Completion: February 1, 2006

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 13, 2005
• First Posted (Estimated): September 21, 2005

Study Record Updates

• Last Update Posted (Actual): May 23, 2025
• Last Update Submitted That Met QC Criteria: May 21, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: colorectal neoplasia; CT colonography; faecal tagging
• Additional Relevant MeSH Terms: Neoplasms
• Other Study ID Numbers: 04/Q0405/CT2