Electrical Impedance measurement as biomarker for brain tumors

Each day, nearly 45 deaths occur due to brain and central nervous system tumors, in the US. Glioblastoma Multiforme (GBM), a fatal form of brain tumor, kills nearly two individuals each hour and has an average 5-year survival rate less than 3%. This indicates that the existing therapies are inadequate. There is a critical need for alternate therapies. Towards this, we propose a simple, straightforward method of using electrical impedance as a biomarker. This could be harnessed to detect tumors at an early stage. A recent study demonstrated the ablation of spontaneous brain tumors in canine patients using irreversible electroporation with minimally invasive electrodes and short duration, high voltage electric pulses. Such electrical treatments hold immense potential for early detection and treatment of malignant tumors. This study explores electrical impedance as a potential biomarker for brain tumors. We measured an average impedance of 20.463 kΩ in ex vivo bovine brain. We also measured current between 0.2 and 0.3 mA in ex vivo brain, under an applied potential of 5V DC between inserted electrodes. Knowing these values gives an estimate of the voltages to apply and the range of impedance and current to expect when trying to distinguish tumor-affected tissue from healthy tissue. The insights obtained from this study will allow the evaluation of electrical impedance as a biomarker for early tumor detection and aid in developing realistic brain phantoms for testing new electrotherapies and drugs.