[Determination of pathological margin of hypopharyngeal cancer by terahertz time-domain spectroscopy system]

Objective:To investigate the accuracy of the terahertz system in differentiating hypopharyngeal cancer from normal tissue and its role in determining the pathological incised margin of hypopharyngeal cancer. Method:The transplantation model of hypopharyngeal cancer in 5-week-old male BALB/c nude mice were established by subcutaneous injection. The obtained transplanted tumor specimens were pathologically diagnosed to determine the extent of tumor tissue. Tumor tissue, normal tissue and paracellular tissue of transplantation tumor were scanned by terahertz time-domain spectroscopy. The differential spectral data were obtained through the detection of frozen tissue sections and paraffin tissue sections, respectively. The results were compared by t-test. Result:The tarahertz absorption coefficient of tumor tissues was higher than that of normal tissues, and the difference was statistically significant when the detection frequency was greater than 0.48 THz in frozen sections（P<0.05）. In the paraffin sections, the difference was statistically significant within the effective spectrum range of 0.2-1.6 THz（P<0.01）. The difference of refractive index between tumor tissue and normal tissue was significant in specimens treated in two ways（P<0.01）. The absorption coefficient of adjacent tissue felt between that of normal tissue and tumor tissue. Conclusion:Terahertz technology can distinguish tumor tissues and normal tissues accurately, and can detect the spectral changes in adjacent tissues sensitively. Therefore, terahertz technology may become another tool for the judgment of pathologic margin.