The use of bioimpedance in the detection/screening of tongue cancer

Oral cancers are the 11th most common malignancy reported worldwide, accounting for 3% of all newly diagnosed cancer cases, and one with high mortality ratios among all malignancies. The objectives of this study were therefore to study the electrical properties of cancerous tongue tissue and normal tongue tissue, as well as to investigate a new approach for low-cost, noninvasive, and real-time screening of oral cancer. Twelve tongue cancer patients and twelve healthy subjects participated in this study. A disposable probe with four silver electrodes was used to measure the electrical properties of patient's and healthy subject's tongue tissues at six different frequencies, which were 20 Hz, 50 kHz, 1.3 MHz, 2.5 MHz, 3.7 MHz and 5 MHz. The amplitude of the applied voltage was limited to 200 mV. Four measurement parameters of impedance, phase angle, real part of impedance, and imaginary part of impedance of tongue were assessed to see if significant difference in values obtained in patient's and healthy subject's tongue tissues existed. Intraclass correlation coefficient showed that all measurements had good reliability and validity (ICC > 0.95 for all measurements). Significant differences were found at 20 Hz (p < 0.05-0.001 for the four measurement parameters) and 50 kHz (p < 0.001 for the four measurement parameters) between patient's and healthy subject's tongue tissues. In conclusion, bioimpedance at a particular frequency is a potentially promising technique for tongue cancer screening.