Raman Spectral Detection And Analysis Of Nasopharyngeal Carcinoma Tissue And Cell Lines

Nasopharyngeal malignancies remain one of the major causes of cancer associated death and have high incidence rates in East Asia, particularly in South China. Presently, routine white-light endoscopy and histological examination are the primary methods for clinical identification of nasopharyngeal carcinoma (NPC). Due to the anatomical position of NPC, it is not easy to diagnosis this lesion early, only about10%and20%of the diagnosed lesions are stage â…  and â…¡ diseases. Almost two thirds of the diagnosed nasopharyngeal carcinoma are at an advanced stage (stage â…¢). Due to the fact that the therapeutic outcome is highly related to the stage of the disease, early identification of malignant nasopharyngeal carcinoma is crucial to improving the survival rate of patients.Recent development of spectral techniques may significantly expand our ability to diagnose this tumor rapidly and accurately. Among the optical approaches currently under investigation for in vivo endoscopic applications, Raman spectroscopy is a very promising technique. Raman spectroscopy is a non-destructive, inelastic light scattering technique in which the scattered photon is shifted to another wavelength with respect to the incident excitation light, depending on the specific vibrational modes of molecules in tissue and cells. Thus Raman spectroscopy reveals specific biochemical information and biomolecular structures of tissue, providing the unique opportunity to distinguish between different pathological tissue types at the molecular level.In this paper Raman spectroscopy was used to detect the signals of normal nasopharyngeal tissue and nasopharyngeal carcinoma tissue as well as three different nasopharyngeal cell lines such as C666, CNE2and NP69. According to the differences of Raman spectroscopy characterization, we are intent to search for a new method which can diagnose nasopharyngeal carcinoma at its early stage. Combined with the new fiber and LD technologies, new instrument of Raman system for in vivo tissue detection was also studied.In the first part of this paper, fundamental theory of Raman spectroscopy was introduced and a brief review of Raman applications in biomedical field was summarized. Then, Raman spectra of nasopharyngeal carcinoma tissue and normal tissue as well as three different cell lines were acquired using a micro-Raman system and a home-made rapid Raman system, respectively. The differences of Raman spectroscopy characterization were analyzed by comparing their spectroscopic intensity and tentative assigned to biochemical components. For further understanding the differences between two different tissues, PCA and LDA was adopted which yielded a diagnostic sensitivity and specificity over than80%.In the end, an endoscopy based rapid Raman detection system was designed and built which is suitable for in vivo measurement. Raman spectra of SCC rat skin tissue were measured and the results have shown the system is reliable and can acquire high quality Raman signals which has a great potential application for in vivo human tissue measurement. All the preliminary results have suggest great potential for using Raman spectroscopy to improve the diagnosis of nasopharyngeal cancer. It provides solid support for us to develop endoscopic Raman instrument for in vivo clinical applications.