Potential Red-Flag Identification of Colorectal Adenomas with Wide-Field Fluorescence Molecular Endoscopy

Area of Science:

• Gastroenterology
• Medical Imaging
• Molecular Diagnostics

Background:

• High adenoma miss rates in colonoscopy, particularly for sessile serrated adenomas/polyps (SSA/Ps) and in high-risk groups like Lynch syndrome patients, necessitate improved detection methods.
• Fluorescence molecular endoscopy (FME) offers enhanced lesion visualization by combining white-light imaging with fluorescence guidance using specific molecular markers.

Purpose of the Study:

• To investigate the clinical feasibility of near-infrared fluorescence molecular endoscopy (NIR-FME) for colorectal adenoma detection.
• To evaluate the efficacy of a fluorescently labeled antibody targeting vascular endothelial growth factor A (VEGFA) for identifying colorectal adenomas.

Main Methods:

• A proof-of-principle study involving 17 patients with familial adenomatous polyposis.
• Intravenous administration of bevacizumab-800CW (a fluorescently labeled anti-VEGFA antibody) at doses of 4.5, 10, or 25 mg.
• Near-infrared fluorescence molecular endoscopy (NIR-FME) performed three days post-injection.

Main Results:

• VEGFA-targeted NIR-FME successfully detected colorectal adenomas across all administered doses.
• The highest dose (25 mg) demonstrated superior performance, detecting even small adenomas (<3 mm).
• Spectroscopy and ex vivo analyses confirmed high tracer concentration and fluorescence within adenoma tissues, with the highest adenoma-to-normal ratio (1.84) in the 25 mg cohort.

Conclusions:

• Near-infrared fluorescence molecular endoscopy (NIR-FME) is clinically feasible for real-time colorectal adenoma detection.
• This technique holds potential as a 'red-flag' system to significantly improve adenoma detection rates during colonoscopy.