A Prospective Study to Evaluate the Diagnostic Accuracy of Computer-aided Diagnosis (CADx) System in Real-time Characterization of Colorectal Neoplasia

Study Overview
=================
Brief Summary
-----------------
The investigators hypothesize that a newly developed CADx system will have a higher diagnostic accuracy in predicting histopathology of colorectal neoplasia than both expert and junior endoscopists.

Detailed Description
-----------------
Accurate diagnosis and characterization of colorectal polyps is essential before endoscopic resection. Optical diagnosis by enhanced imaging modality (e.g. Narrow Band Imaging, NBI) allows real-time prediction of histopathology. It can assist endoscopists to select the appropriate technique and differentiate between neoplastic or non-neoplastic polyps. Nevertheless, due to the substantial inter-observer variability, the widespread use was limited. Recently, artificial intelligence and computer-aided polyp diagnosis (CADx) systems have evolved rapidly. The major limitation was the heterogeneity from different types of imaging modalities. Endocytoscopic images require extra steps for pre-staining and magnification, which are time consuming and operator dependent. As a result, it limits the generalisability and applicability in real-world settings. A novel CADx system will be developed for real-time histopathological prediction of colorectal neoplasia, by using non-magnified conventional white-light and image enhanced endoscopy (NBI). The diagnostic accuracy of this CADx system will be compared with both expert and junior endoscopists.

Official Title
-----------------
A Prospective Study to Evaluate the Diagnostic Accuracy of Computer-aided Diagnosis (CADx) System in Real-time Characterization of Colorectal Neoplasia

Conditions
-----------------
Colorectal Neoplasms

Intervention / Treatment
-----------------
* Device: CADx


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: They have received colonoscopy for screening, surveillance or symptom investigation; They have endoscopic images and videos captured and stored during colonoscopy which are available to be retrieved; They have histologically proven colorectal neoplasia. Written consent obtained Exclusion Criteria: Poor quality endoscopic images and videos defined as: Incomplete visualization of the colorectal neoplasia due to technical reasons (e.g. out-of-focus, motion-blurred or insufficient illumination); Artifacts due to mucus, air bubbles, stool, or blood. Active gastrointestinal bleeding; Fulminant colitis; Obscured view due to poor bowel preparation; Artificial staining of lesion due to chromoendoscopy. Unable to obtain informed consent

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CADx<br>Histopathology prediction by CADx device | Device: CADx<br>* A novel CADx system for real-time histopathological prediction of colorectal neoplasia, by using non-magnified conventional white-light and image enhanced endoscopy.<br>|
| Endoscopist<br>Real-time histopathology prediction by expert and non-expert endoscopists | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy | area under receiver operating characteristic curves, AUROC in prediction of final histopathology | During the colonoscopy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity | Sensitivity | During the colonoscopy | 
| Specificity | Specificity | During the colonoscopy | 
| Positive predictive value | Positive predictive value | During the colonoscopy | 
| Negative predictive value | Negative predictive value | During the colonoscopy | 
| Diagnostic time | Diagnostic time | During the colonoscopy |