[FTIR spectroscopic explorations of freshly resected thyroid malignant tissues].

In the present paper, 17 cases of freshly resected malignant thyroid tissue samples and 23 cases of benign thyroid tissue samples were characterized using FTIR spectroscopy with an ATR probe. Statistic analysis indicated that the FTIR spectra of cancerous tissue were significantly different from those of benign tissue. In comparison with normal tissues, the FTIR spectra of malignant thyroid tissues possess the following features: (1) Variation of bands related to protein: Amide I band shifted to lower wave number significantly (P<0.01), while amide II band shifted to higher wave number(P<0.05), and the ratios of I1640/I1460 and I1640/I1550 were raised (P<0.01). The authors can conclude that the amounts and the secondary structure of protein in malignant tissue changed. (2) The peaks at 2955, 2920, 2870, 2850 and 1740 cm(-1) appeared less frequently suggesting that the relative quantity of lipid in malignant tissue decreased significantly; (3) Variation of bands related to nucleic acid: The band of 1241 cm(-1) shifted to (1238.29+/-2.87)cm(-1), and the ratios of I1080/I1460 were raised significantly(P<0.05). The most possible reason for the changes was that the mutation of DNA and the amounts of nucleic acid had increased in malignant neoplasms. Experimental results show that the malignant thyroid tissues can be distinguished from the benign tissues by their infrared spectra. This approach proves that FTIR spectroscopy is a reliable and practicable method for thyroid cancer diagnosis in operations. The authors have expanded their research on detecting the thyroid cancer FTIR spectra via percutaneous and in vivo, and have achieved a positive result which is going to be reported in another paper.