Endoscopic optical coherence tomography and laser-induced fluorescence spectroscopy in a murine colon cancer model

Abstract
Background and Objectives The diagnostic feasibility of optical coherence tomography (OCT) and laser‐induced fluorescence (LIF) have been evaluated for human colorectal cancer. This study applies these technologies to a murine model of colorectal adenoma. Study Design/Materials and Methods The lower colon of 10 ApcMin and two C57BL/6J mice was surveyed over five 4‐week intervals using a prototype 2.0 mm diameter OCT‐LIF endoscope‐based system. Four categories were histologically classified: control C57BL/6J, adenomatous, non‐diseased regions of adenomatous, and non‐diseased ApcMin. OCT images were compared to histology. Spectra from the four categories were compared via the Student's t‐test. Results Three ApcMin and two control mice completed the study. One adenoma was histologically identified; OCT visualized mucosal thickening/abnormal mass development over the imaging timepoints. LIF spectral comparisons revealed decreased 405 nm intensity and the presence of a peak at 680 nm in the adenomatous ApcMin. Conclusions These preliminary data indicate endoscopic OCT‐LIF has the potential to identify colorectal adenomas in murine models. Lasers Surg. Med. 38:305–313, 2006.