A Randomized Controlled Trial Comparing High-definition White Light Colonoscopy to I-Scan Enhanced Colonoscopy for Adenoma Detection in a Population at Increased Risk of Colorectal Cancer. A Pilot Study
Colorectal Cancer is the third most common cause of cancer in Canada with an estimated
lifetime risk of developing the disease of 6-7%. Each year there are approximately 21,000
new cases and 9,100 deaths attributable to this disease. Colonoscopy is one of several
methods recommended for CRC screening by current guidelines. While colonoscopy is the most
invasive, it offers high diagnostic accuracy and ability for therapy (biopsy and removal of
adenomas) compared to other modalities. The emerging evidence regarding missed neoplastic
lesions with colonoscopy has resulted in quality initiatives designed to improve colonoscopy
performance. I-Scan (Pentax, Montvale, NJ) is a new method that uses post processing
computer algorithms to revise the standard white light to highlight pit patterns and
vascular surface patterns.The relevant I-scan settings in the colon are I-scan 1 and I-scan
2. The primary objective of the study is to compare the adenoma detection rate in the right
colon using High-definition white light colonoscopy versus I-scan enhanced colonoscopy.
All patients referred for a screening colonoscopy at Forzani and MacPhail Colon Cancer
Centre will be considered for enrollment.All eligible patients that are not part of another
research study will be approached for enrollment into the study. During the pre-assessment
at the clinic a study assistant will contact all the eligible patients to describe the study
and provide an "Invitation to participate in a Research study" form. The study assistant
will obtain a final consent if they agree. Those not interested will simply receive the
Centre's standard protocol. There will be no coercion of any sort. Following Informed
Consent, treatment allocation through computer generated randomization will be revealed.
Patients will be allocated to one of the three study arms (HD Colon, I-scan 1 and I-Scan 2).
Patients will receive a standard bowel preparation: Split dose Polyethylene Glycol (PEG) (2L
at noon + 2L at 8 PM the day before) for morning procedures or (2L at 8Pm the day before
and 2L at five hours before the procedure on the day of colonoscopy) for afternoon
procedure. certified gastroenterologists will perform all of the procedures with the
assistance of a nurse. The planned "second look" of the right colon will involve withdrawing
from the Cecum to Hepatic flexure, then re-inserting to Cecum and finally withdrawing
through the entire colon. The physician performing the procedure will then fill a
"Colonoscopy Report Form" including the number of polyps detected, size, shape, polypectomy
method and cleanliness of the bowel.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Screening
Mean number of adenomas per colonoscopy
The "Colonoscopy Report Form" completed by the Physician helps to assess the number of polyps and a endoscopic description (location, size, shape) of these lesions including. Following formal review by the pathologist the polyp classification (e.g. whether it is an adenoma) is determined.
Colonoscopy report form provided to the physician will be filled out and collected after the procedure (1 hour). All polyps reviewed by pathologist (1 week).
Robert Hilsden, MD
Faculty of Medicine, University of Calgary
Canada: Health Canada