Electrical Impedance Spectroscopy of Prostate as an Alternative Tool for Cancer Detection
The biophysical mechanisms influencing the electrical properties of tissues is a complex interplay between tissue morphology, cellular phenotypes, cell wall integrity, intra- and extra-cellular ionic concentrations, pH, temperature, and velocity in fluids, among others.
Some of these features dominate the underlying electrical properties and are able to provide significant contrast between tissue types or pathologies. Electrical impedance spectroscopy of tissue is a technology in which small alternating currents are injected between pairs of electrodes in contact with a tissue specimen. Voltages are recorded from the same pair or another pair of electrodes. The voltage-to-current ratio defines the electrical impedance of the tissue. By recording this impedance over a range of alternating current signal frequencies, we can generate a spectrum of impedance properties. Interestingly, benign and malignant tissues have vastly different appearances microscopically, which give rise to significantly different electrical impedance spectra. We have been exploring the impedance contrast available for use in prostate cancer detection and have demonstrated a number of significant contrasts. Based on these findings, our group has been developing a number of potential clinical applications to take advantage of this contrast.