Dielectric Properties for Differentiating Normal and Malignant Thyroid Tissues

BACKGROUND The incidence rate of thyroid cancer has increased greatly during the last few decades, and highly sensitive and specific methods for early diagnosis and prognostic evaluation remain lacking. In this study, we investigated a novel approach based on microwave theory to detect thyroid cancer. MATERIAL AND METHODS Freshly excised thyroid tissues (n=236) from 48 patients were identified as normal or malignant using histology. Each sample was measured for effective dielectric permittivity and effective conductivity (0.5-8 GHz). The means of each of these parameters of the normal and malignant groups were compared. RESULTS The effective dielectric permittivities of normal and malignant thyroid tissues were 24.026±1.951 to 17.950±1.648 and 69.782±2.734 to 57.356±1.802, respectively. Also, as a function of frequency, the effective conductivities of normal and malignant thyroid cancer were 0.8395±0.2013 to 1.8730±0.0979 and 1.8960±0.5024 to 9.7461±0.9349 (S/m), respectively. The mean effective dielectric permittivities and effective conductivities of normal thyroid tissues were significantly lower than that of thyroid cancer tissues. CONCLUSIONS Measuring the effective dielectric permittivity and effective conductivity of excised thyroid tissues may be a new and viable method to determine malignancy in thyroid cancer.