Investigation of normal and malignant laryngeal tissue by autofluorescence imaging technique

Objective: During oncogenesis significant changes in tissue properties occur that result in alteration of fluorescence characteristics of the tissue. The differences in autofluorescence between normal and malignant tissues offer new possibilities in detecting epithelial pathological lesions. Aim: The aim of our study was to determine the usefulness of autofluorescence technique in diagnostic of laryngeal tumors. Material and methods: Fluorescence in larynxes from 10 laryngectomized cancer patients was induced by excitation light at 360–450 nm wavelength. As a light source, mercury lamp and laser (404 nm) were used. The CCD camera captured the fluorescent light emitted. Normal epithelium and cancer tissue were also analyzed on fluorescence microscopy. Results: Laryngeal carcinoma tissues when excited with ultraviolet or blue light generate attenuated or absent autofluorescence in the green light band compare with normal epithelium where strong signal around 505 nm was detected. Average value of maximal autofluorescence intensities was 26.2 V (range 18–35) and 4.4 V (range 2–8) in healthy and cancerously changed mucosa respectively. Spectral analysis revealed that autofluorescence signal from unchanged mucosa (around 505 nm) was significantly higher compared to cancer tissue (P=0.005). Conclusions: It seems that autofluorescence imaging may be a supplementary tool in diagnosis of laryngeal tumors.