CT Colonography as the Initial Diagnostic Imaging Tool for Patients With Suspected Colorectal Cancer

Observational Study to Compare the Utilisation of CT Colonography With Optical Colonoscopy as the First Diagnostic Imaging Tool in Patients With Suspected Colorectal Cancer

This study aims to evaluate whether the use of Computed Tomography Colonography (CTC) for patients with low to intermediate risk of suspected colorectal cancer decreases overall NHS costs and waiting times whilst increasing patient satisfaction compared to clinical practice with utilisation of Optical Colonoscopy.

Given the recent change in the NICE guidance for the cancer pathway referral for patients with suspected colorectal cancer (See NG12), there will be an increase in demand for optical colonoscopy. Optical colonoscopy is technically difficult, resource intensive and associated with complications; therefore the increased use of CT Colonography (CTC) should be considered as an alternative. The diagnostic efficacy of CTC, in comparison to optical colonoscopy, is well established and has been shown to be accurate for identifying malignancies and medium to large polyps (≥6mm) with a greater level of patient acceptability.

The use of CTC as the first diagnostic imaging tool would identify those patients who would benefit from further investigation (colonoscopy or flexible sigmoidoscopy) to occur on the same day, as well as ruling out those who do not require further testing. This would then ensure that colonoscopy capacity can be prioritised appropriately to support the increase in demand due to the NICE guidance changes.

Inclusion Criteria:

• Every adult patient over 40 years old, presenting with constipation or alternating change in bowel habits, with a differential diagnosis of suspected colorectal cancer.

Exclusion Criteria:

• Patients presenting with anaemia;
• Patients presenting with diarrhoea only for more than 6 weeks;
• Patients presenting with rectal bleeding;
• Patients who have undergone a previous whole-colon examination in the past 6 months;
• Patients who have been referred for a whole-colon examination to follow up already diagnosed colorectal cancer;
• Patients lacking capacity to give consent or participate in the study;
• Patients already taking part in any clinical trial of an investigational medicinal product (CTIMP);
• Prisoners
• Patients who are not fluent in English.