Electrical Properties of Prostatic Tissues: I. Single Frequency Admittivity Properties

Abstract

Purpose Electrical properties of the prostate may provide sufficient contrast for distinguishing malignant and benign formations in the gland. We evaluated how well these electrical properties discriminate cancer from noncancer tissues in the prostate. Materials and Methods Electrical admittivity (conductivity and permittivity) was recorded at 31 discrete frequencies of 0.1 to 100 kHz from each of 50 ex vivo human prostates. A specifically designed admittivity probe was used to gauge these electrical properties from sectioned prostate specimens. The specific tissue area probed was marked to provide precise colocalization between tissue histological assessment and recorded admittivity spectra. Results Adenocarcinoma, benign prostatic hyperplasia, nonhyperplastic glandular tissue and stromal tissue were the primary tissue types probed. Mean cancer conductivity was significantly less than that of glandular and stromal tissues at all frequencies (p <0.05), while mean cancer permittivity was significantly greater than that of all benign tissues at 100 kHz (p <0.0001). ROC curves showed that permittivity at 100 kHz was optimal for discriminating cancer from all benign tissues. This parameter had 77% specificity at 70% sensitivity and an ROC AUC of 0.798. Conclusions The contrast in electrical admittivity properties of different prostate tissues shows promise for distinguishing cancer from benign tissues. Sensitivity and specificity exceed those reported for current prostate specific antigen screening practices at low prostate specific antigen, making this an attractive addition to the clinical armamentarium for identifying prostate cancer.

Electrical impedance spectroscopy for prostate cancer diagnosis

“…This may arise from actual variation in the tissue or in the probe construction. Moderate tissue impedance variation between multiple tissue samples has been previously reported to be on the order of 15% [6]. Probe construction took place in a laboratory setting.…”

“…The conventional biopsy technique samples a very small volume of prostate gland (typically <1% of 24cm 3 prostate) leading to misdiagnosis and inaccurate assessment of disease severity [1] [2] [3]. Previous studies have shown the significant contrast between electrical properties of benign and malignant tissues [4] [5] [6] [7]. These contrasts are due to morphological differences present in the different prostatic tissue types.…”

A novel multiple electrode direct current technique for characterisation of tissue resistance during surgery

“…More localised measurements using the mechanical [8] or electrochemical (EC) and electrical properties of tissue may offer an alternative to imaging and can arguably deliver a faster route to surgical integration [9][10][11]. Electrical tissue characteristics, measured using the AC technique of Bioimpedance Spectroscopy (BIS), have shown differences between healthy and diseased tissues.…”

“…Electrical tissue characteristics, measured using the AC technique of Bioimpedance Spectroscopy (BIS), have shown differences between healthy and diseased tissues. [10][11][12] these differences are often target tissue specific and require specific frequency range selection and complex electronic model analogies to be applied in order to make statistical distinction. A DC biogalvanic method for tissue characterisation has also been investigated as a means of determining the electrical properties of tissue [13].…”

Feature-space assessment of electrical impedance tomography coregistered with computed tomography in detecting multiple contrast targets

“…[1][2][3][4][5][6][7][8] Currently, EIT is the only known imaging modality which generates conductivity images. In EIT, measurements are normally made by placing 8-32 electrodes on the surface of the imaging object and injecting a low frequency alternating current through a pair of electrodes.…”