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 26.2V (range 18-35) and 4.4V (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.

Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy.

BACKGROUND: The main problem after percutaneous coronary intervention (PCI) is restenosis affecting the site where dilatation is performed. In order to minimize its occurrence, the method of intravascular laser photostimulation (LP) with low power irradiation has been developed. The new procedure is carried out during PCI. MATERIAL/METHODS: A special setup was prepared for intravascular photostimulation with 808 nm wavelength laser diode and special diffuser, delivering the laser light into the coronary artery. The construction of the device makes it possible to irradiate the coronary artery in the place of previously performed of dilatation, in an satisfactory and programmable manner and with uniform intensity. We describe our own, unique LP procedure. Two pilot LP procedures carried out in our clinic are described here. The patients were diagnosed before treatment and followed up three and six months after the LP procedure with non invasive tests. After six months, a control angiography was also performed. RESULTS: The procedures were well tolerated. In both cases the follow-up examinations showed no evidence of restenosis. CONCLUSIONS: The new, innovative technique of intravascular low power laser photostimulation is a relatively inexpensive and easy to use treatment method. No negative side effects were observed after two procedures. The results obtained are very promising. Because the group of treated patients is still too small, the results cannot yet be subjected to statistical analysis.