Electrical Impedance Tomography for Robot-Aided Internal Radiation Therapy

Abstract

High dose rate brachytherapy (HDR) is an internal based radiation treatment for prostate cancer. The treatment can deliver radiation to the site of dominant tumor growth within the prostate. Imaging methods to delineate the dominant tumor are imperative to ensure the maximum success of HDR. This paper investigates the feasibility of using electrical impedance tomography (EIT) as the main imaging modality during robot-aided internal radiation therapy. A procedure utilizing brachytherapy needles in order to perform EIT for the purpose of robot-aided prostate cancer imaging is proposed. It is known that cancerous tissue exhibits different conductivity than healthy tissue. Using this information, it is hypothesized that a conductivity map of the tissue can be used to locate and delineate cancerous nodules via EIT. Multiple experiments were conducted using eight brachytherapy needle electrodes. Observations indicate that the imaging procedure is able to observe differences in tissue conductivity in a setting that approximates transperineal HDR and confirm that brachytherapy needles can be used as electrodes for this purpose. The needles can access the tissue at a specific depth that traditional EIT surface electrodes cannot. The results indicate the feasibility of using brachytherapy needles for EIT for the purpose internal radiation therapy.

A pilot study of contrast-enhanced electrical impedance tomography for real-time imaging of cerebral perfusion

“…Electrical impedance tomography (EIT) is a portable, economical, safe, and constant real-time imaging technology, which applies a safe excitation current to the human body through contact electrodes, and the resulting changes in impedance distribution allow reconstructed image analysis using algorithms ( Holder, 2005 ; Adler and Boyle, 2017 ; Pan et al, 2020 ). Due to its advantages, such as small time interval for data collection, sensitivity to changes in electrical conductivity of different tissues, and that it requires no use of radiation, EIT has been widely applied in many fields, for instance, lung respiratory function imaging ( Aguiar Santos et al, 2018 ; Tomicic and Cornejo, 2019 ), prostate cancer detection function imaging ( Tan and Rossa, 2021 ), and abdominal organ function imaging ( Shuai et al, 2009 ).…”