What alternatives are available for procedures to check for colorectal polyps?

From the Guidelines

Virtual colonoscopy (CT colonography) is a valid alternative to standard colonoscopy for checking for polyps, with a sensitivity of 93% and a specificity of 97% for detecting polyps > 1 cm, as reported in the study by 1. Several alternatives are available for checking for polyps beyond the standard colonoscopy.

• Virtual colonoscopy (CT colonography) uses CT scanning to create detailed images of the colon without requiring a scope insertion.
• Flexible sigmoidoscopy examines only the lower part of the colon and rectum but is less invasive than a full colonoscopy.
• Stool-based tests include the fecal immunochemical test (FIT), which detects hidden blood that might indicate polyps, and stool DNA tests like Cologuard, which look for altered DNA from polyps or cancer cells.
• Capsule colonoscopy involves swallowing a pill-sized camera that takes images as it passes through the digestive tract, with second-generation colon capsules (CCE-2) having improved image acquisition and sensitivity of 82% and specificity of 86% for detection of any polyp, as reported in the study by 1.
• Double-contrast barium enema is an older X-ray technique that can detect larger polyps. Each alternative has different sensitivity levels, with colonoscopy remaining the gold standard for detection and removal of polyps, as stated in the guideline by 1. The best option depends on individual risk factors, personal preferences, and medical history. Most alternatives, if positive, will still require a follow-up colonoscopy for polyp removal, as only traditional colonoscopy allows for both detection and removal during the same procedure. It is essential to consider the patient's preferences and availability of the screening modalities, as well as the limitations and potential side effects of each alternative, such as the extensive laxatives required for capsule colonoscopy, as mentioned in the study by 1.

From the Research

Alternatives to Traditional Procedures for Checking Polyps

There are several alternatives to traditional procedures for checking polyps, including:

• CT-colonography (CTC) 2, 3, 4
• MR-colonography (MRC) 2
• Computed tomographic colonography (CTC) as a non-invasive method for colon imaging 2, 3, 4
• Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) techniques for managing large and flat lesions 5

Characteristics of Alternative Procedures

These alternative procedures have the following characteristics:

• CTC and MRC require bowel preparation, but preliminary studies have been carried out without colon preparation 2
• CTC has a high sensitivity and specificity for polyps > or = 10 mm, comparable to conventional colonoscopy 2
• EMR and ESD techniques are complex and require extensive knowledge and skill in the use of various devices to resect a lesion completely and manage bleeding and perforation associated with these procedures 5
• CTC has a lower detection rate for high-risk sessile serrated polyps compared to colonoscopy 4

Advantages and Disadvantages of Alternative Procedures

The advantages and disadvantages of these alternative procedures are:

• Advantages: non-invasiveness, no need for sedation, and probably no bowel preparation 2
• Disadvantages: radiation dose during CT colonography, lower detection rate for high-risk sessile serrated polyps 2, 4