Cancer diagnostics using Fourier transform fiberoptic infrared evanescent wave spectroscopy (FTIR-FEWS)

A Fourier Transform Infrared spectrometer and infrared transmitting AgClBr fibers were used for fiberoptic evanescent wave spectroscopy (FTIR-FEWS) of cancer. Malignant and healthy tissue samples were extracted from patients at the Meir Hospital in Israel, placed on a Silver Halide fiber, and measured using the FTIR -FEWS system. The infrared spectra were analyzed and compared by taking the ratio of absorption of the active functional groups of Amide I at 1642 cm(-1) and Amide TI at 1545 cm(-1). Clear differences appeared between the two types of tissue. When placing the tissue samples on bare fiber the reproducibility of the results was not satisfactory due to chemical interaction between the tissue and the fibers. This problem was solved by applying Polyethylene coating of thickness 1-2 mu m on the fiber, leading to reproducible results. The results of these preliminary studies indicate that the FTIR-FEWS technique can be used for cancer diagnostics. Combined with endoscopy this technique could be used to analyze tissues inside the body in vivo and in real time.