In vivo molecular imaging of epidermal growth factor receptor in patients with colorectal neoplasia using confocal laser endomicroscopy

Abstract

Epidermal growth factor receptor (EGFR) plays an important role in tumorigenesis of colorectal cancer (CRC), and its in vivo molecular imaging in rodent models has become the subject of an increased number of studies using novel imaging techniques for gastrointestinal endoscopy. Current study aimed to evaluate the use of confocal endomicroscopy (CLE) for in vivo molecular imaging of EGFR in patients with colorectal neoplasia. Molecular imaging of colorectal neoplasia in patients was performed by CLE after topical application of a fluorescent-labeled molecular probe against EGFR. Representative images of CLE were chosen to calculate EGFR-specific fluorescence intensity. Targeted biopsy specimens were taken from each examined site during in vivo imaging for histology and immunohistochemistry (IHC). During in vivo molecular imaging in 37 patients, an EGFR-specific fluorescence signal was present in 18/19 CRC, and 12/18 colorectal adenomas. No or only weak fluorescence signal was observed in vivo in 10 cases of normal mucosa. CLE is a novel tool that could be used in molecular imaging with specific targeting of EGFR in patients with colorectal neoplasia. This technique demonstrates a promising imaging approach for targeted therapies of colorectal neoplasia.