In vivoelectrical conductivity of hepatic tumours

Abstract

Knowledge of electrical tissue conductivity is necessary to determine deposition of electromagnetic energy and can further be used to diagnostically differentiate between normal and neoplastic tissue. We measured 17 rats with a total of 24 tumours of the K12/TRb rat colon cancer cell line. In each animal we measured in vivo hepatic tumour and normal tissue conductivity at seven frequencies from 10 Hz to 1 MHz, at different tumour stages between 6 and 12 weeks after induction. Conductivity of normal liver tissue was 1.26 +/- 0.15 mS cm(-1) at 10 Hz, and 4.61 +/- 0.42 mS cm(-1) at 1 MHz. Conductivity of tumour was 2.69 +/- 0.91 mS cm(-1) at 10 Hz, and 5.23 +/- 0.82 mS cm(-1) at 1 MHz. Conductivity was significantly different between normal and tumour tissue (p < 0.05). We determined the percentage of necrosis and fibrosis at the measurement site. We fitted the conductivity data to the Cole-Cole model. For the tumour data we determined Spearman's correlation coefficients between the Cole-Cole parameters and age, necrosis, fibrosis and tumour volume and found significant correlation between necrosis and the Cole-Cole parameters (p < 0.05). We conclude that necrosis within the tumour and the associated membrane breakdown is likely responsible for the observed change in conductivity.

Selective Electroporation of Liver Tumor Nodules by Means of Hypersaline Infusion: A Feasibility Study

“…High voltage was applied between parallel plates located at the top and bottom of the liver. Reported healthy liver conductivities goes from 0.03 S/m [5] to 0.12 S/m [6]. At the same time is commonly reported a significantly higher conductivity of tumor than healthy one.…”

“…At the same time is commonly reported a significantly higher conductivity of tumor than healthy one. Taking into account the liver conductivity obtained during in vivo experiments, the values previously reported in [6] were used (Table 1). With these values is possible to calculate the electric field distribution within the model when a certain electric potential is applied between both electrodes.…”

Electrotherapy on Cancer: Experiment and Mathematical Modeling

“…When this equilibrium is broken, the tumors make more heterogeneous due to the presence of necrosis, infiltration to tissues, among other alterations. The fact that tumor conductivity is assumed higher than that its surrounding healthy tissue is justified because neoplasic tissues exhibit somewhat larger conductivity and permittivity values than homologous normal tissues due to that the water content is higher in the tumor [Foster & Schwan, 1996;Haemmerich et al, 2003;Haemmerich et al, 2009;Miklavčič et al, 2006;Ng et al, 2008;S.R. Smith et al, 1986, D.G.…”

Magnetoacoustic tomography with magnetic induction for biological tissue imaging: numerical modelling and simulations

“…In recent years noninvasive electrical conductivity imaging has been especially investigated, because electrical properties of biological tissues are known to be sensitive to physiological and pathological conditions of living organisms. For instance, human breast cancer or liver tumor cells have a significantly higher electrical conductivity than a healthy tissue [1,2].…”