Detection of Cancer by Raman Spectroscopy
Raman and luminescence spectroscopy is the most advanced modern technology for performing an “optical biopsy” of the tissue. They are used as noninvasive means of diagnosing various diseases and pathological conditions, including tumors of different localizations. Raman spectroscopy relies on the interaction of laser radiation with the tissue. The illuminated sample scatters the light, thereby changing the radiation frequency. Consequently, the frequency shift measured by the spectrometer corresponds to the vibrational and rotational excitations of structural elements of the tissue under investigation. Thus, each substance constituting the tissue is characterized by a set of Raman lines with certain spectral positions and fixed relative intensities. This unique combination of spectral parameters – Raman molecular “fingerprint” – enables the detection of variations in cellular metabolism. Tumor development is accompanied by structural and biochemical modifications of the tissue. Raman spectroscopy registers these changes and makes possible identification of various morphological forms of cancer and concurrent hyperplastic or preneoplastic processes. Raman method proved to be efficient in detecting breast, skin, prostate, cervical, and endometrial cancer.