Laser-Induced Fluorescence at 488 nm Excitation for Detecting Benign and Malignant Lesions in Stomach Mucosa

Abstract

This work aims the detection of the histopathologic alterations of in vitro human gastric mucosa using spectral informations from laser-induced fluorescence spectroscopy (LIFS) technique with excitation at 488 nm (argon laser). A total of 108 biopsies with endoscopic diagnosis of gastritis and gastric cancer were obtained at the antral gastric region, from 35 patients with dyspeptic digestive complaints. The biopsies were collected during the endoscopic examination. On each biopsy fragment the autofluorescence spectrum was collected in two random points, through a fiber-optic catheter coupled to the excitation laser. The fluorescence emission spectra collected by the fibers were directed to the spectrograph and detected by the CCD camera. The spectra were then separated in groups (N, normal; LI, light inflammation; MI, moderated inflammation; CA, adenocarcinoma), based on the histopathology. The ratio between the emission wavelengths 550 and 600 nm was used as a diagnostic parameter. Analysis of fluorescence spectra was able to identify the normal tissue from adenocarcinoma lesions with 100% of sensibility and specificity. The ratio intensities between inflammation (light and moderated), although presented significantly statistical differences when compared to the normal mucosa, do not furnish enough sensibility and specificity for use as an identification method due to high variations. LIFS, with excitation of 488 nm, could be used in the differentiation of normal tissue and neoplasic lesions, assisting a less invasive diagnosis.

The delayed fluorescence kinetics as a method of biological tissue diagnostics

“…For example, the increase of porphyrin derivable luminescence intensity is a result of the cells concentration increase. However until now we haven't had the exact image of porphyrin concentration increase in pathological tissue [12][13][14][15] . These shortcomings might be not so vivid if fluorophores excited state period is tacken into consideration.…”

Extending immunofluorescence detection limits in whole paraffin‐embedded formalin fixed tissues using hyperspectral confocal fluorescence imaging

“…Based on this comparison, it is suggested that the bulk of the autofluorescence observed in these sections is due to a combination of elastin and FAD fluorescence. This conclusion is consistent with the findings of previous studies at this excitation wavelength, as well as from the spectra contained in the EEM database (Benson et al ., 1979; Izuishi et al ., 1999; Silveira et al ., 2007).…”

An Assessment of the Impact of Zidovudine on Rat Teeth Ontogenesis with Quantitative Laser Induced Fluorescence and an Histomorphological Analysis

“…The fluorescent properties of molecules present in the different tissues of living organisms were used to evaluate and monitor their actual metabolic activity, determine the redox status, oxygen concentration in tissues, mitochondrial insufficiency as well as assess the degree of bone tissue maturity, the presence of mineral compounds in teeth and detect microorganisms in living tissues [9][10][11][12][13][14]. Knowledge of the status of the above characteristics of an organism helps ensure early detection of subclinical pathologies, including early detection of premalignant and neoplastic changes [10,[15][16][17][18][19][20] and differential diagnosis of different types of pathological changes [9,19]. It can also be used to assess the impact of drugs on tissues [21,22], distinguish between healthy body tissues and dysplastic lesions [19], evaluate tumour lesion demarcation [19,23,24] and provide early detection of initial caries in teeth [12,[24][25][26][27].…”