An analysis of LIF spectrum for detecting colorectal carcinoma in vivo and in vitro / 中华消化内镜杂志

ABSTRACT

Objective To study the correlativity of laser-induced fluorescence (LIF) spectrum on the same specimen of colorectal carcinoma both in vivo and in vitro and to obtain the best diagnostic parameter in detecting colorectal carcinoma. Methods LIF spectra were analyzed from 10 patients with colorectal carcinoma during colonoscopy, and then analyzed again after resection. The cancer foci and normal mucosa more than 5 cm apart from the foci were excited by a nitrogen laser (337 nm)using a quartz optical fiber in gentle contact with the area of interest, and then the fluorescence emission was collected by the same quartz optical fiber. The LIF spectrum was analyzed using an optical multichannel analyzer (OMAⅢ). Results (1)The LIF spectrum from cancer tissues was same as that of normal tissues, both showed the main and the second peak respectively located at about 460 nm and 390 nm in vivo and in vitro. The main peak intensities in vivo from both cancer and normal tissue were significantly lower than these in vitro. The main peak intensities in vivo and in vitro from cancer tissue were decreased about 1 time to those from normal tissue.(2) The integrated spectral intensity in vivo and in vitro of cancer tissue from each patient was significantly lower than that from the corresponding normal tissue respectively, P