Optical coherence tomography (OCT) has been demonstrated to be a powerful tool for noninvasive, real-time oral cancer diagnosis. However, in previous reports, OCT has still been found to be difficult to use in the diagnosis of oral precancerous stages, including mild dysplasia and moderate dysplasia. In clinical applications, early diagnosis and treatment of oral cancer can greatly improve the survival rate. Therefore, in this study, we propose a new approach to differentiate the oral precancerous stages based on the evaluation of the optical scattering properties of the epithelial layer, which is where the dysplastic cells start to develop in the precancerous stages. Instead of using exponential decay fitting to evaluate the scattering properties of mucosal tissues based on the Beer–Lambert law, linear fitting of the OCT depth intensity is used to evaluate the scattering properties of normal and dysplastic cells. From the statistical results of the linear fitting, the slope, a, can be an effective indicator to discriminate healthy mucosa and moderate dysplasia when an a value equal to zero is the threshold value, and the intercept, b, can be used to differentiate healthy and dysplastic mucosae, as well as mild and moderate dysplasia, when b values of 0.15 and 0.18 are used as the threshold values, respectively. Furthermore, this approach is also applied to the determination of the safe margin between normal and abnormal mucosae, making it possible to provide real-time, in vivo inspection during oral maxillofacial surgery.

Spectral changes of lung cancer serum in the process of tumor evolution were investigated in this study. We kept close watch on the tumor progression of a group of patients, and measured their serum spectra using 488.0nm and 514.5nm excitation of an Ar-ion laser once a week. There was no apparent change observed in fluorescence spectrum in different period. However, the relative intensity of three Raman peaks (mode A, B and C) decreased every week later. For quantitative analysis of such changes, a parameter Ir (relative intensity of C Raman peak) was introduced and Ir-value was calculated. Calculation showed that Ir-value was degressive with tumor evolution, but β (Ir5145/Ir4880) varied irregularly. To the end, no Raman peak was observed. We assumed that three Raman peaks were derived from beta carotene. It indicated that the content of beta carotene decreased with the aggravation of lung cancer.

No abstract

In this paper, we present a three parametric model using Raman and fluorescence spectroscopy for detection and analysis of esophagus dysphasia and esophagus cancer. The model was set up from more than 200 samples. And 40 samples were used to test this algorithm of the model prospectively. The serum spectra were excited by laser of the wavelength 488.0 nm and 514.5 nm. The apparent differences of auto-fluorescence and Raman spectroscopy were observed for patients compared to the normal: the majority of the fluorescence spectra did not have violent alteration, but three Raman peaks had disappeared or very weak. For successful operation, the Raman spectrum of patient's serum is similar to the normal. Moreover, Delta lambda value(red shift of fluorescence peak) and alpha-value (rate of fluorescence intensity) also provide the reference for future research. And beta-value(rate of Raman peak intensity) will decrease with progression of the tumor. The result of spectrum analysis is accordance with the clinical diagnosis.

No abstract