The primary objective of surgical therapy for the treatment of patients with cancer is to remove all cancer cells from within the body, with the secondary objective of maintaining organ function. The primary pathological metric used to rate the success of a surgical procedure is evaluation of the surgical margin of the resected tissue specimen, post-operatively. This typically involves cutting the tissue into sections and microscopically exploring these tissue samples for the presence of cancer cells at the margins. Cancer cells noted at the margins represent Positive Surgical Margins (PSMs) and suggest that cancer cells were left in the body following the procedure. As a result, patients with PSMs are often exposed to noxious additional procedures to eradicate the cancer cells left behind including radiation, chemical, hormonal, and additional surgical therapy; these all have adverse morbidities that decrease a patient's quality of life. No clinical protocols are routinely used to intraoperatively assess surgical margin status during surgical procedures. Instead, margins are evaluated through microscopic assessment of the tissue following the procedure, when it is too late to provide additional surgical intervention.
We aim to develop an intraoperative device able to assess surgical margin status so that the surgeons can extract additional tissues in real-time and ultimately decrease the rates of PSMs. While our technology can be applied for most cancer surgeries, we are focusing our efforts on prostate cancer as these are the highest incidence and cause of death for men and because patients with PSMs following these procedures have a much higher rate of recurrence than patients that have negative surgical margins. We have previously shown that the electrical impedance (a property that describes how easily electrical current passes through a tissue) of tissue is sensitive to a tissue's cellular arrangement and can be used to distinguish cancer from benign tissue in prostate. We have developed a prototype flexible endoscopic device capable of imaging the electrical impedance tissue during radical prostatectomy procedures using Electrical Impedance Tomography (EIT) techniques. This device makes focal measurements of margin status. Here we aim to take the significant step of constructing an optimized EIT device that can be deployed laparoscopically (e.g. prostate surgery) to provide an accurate method of intraoperatively identifying positive surgical margins.
We aim to develop this device, develop intraoperative visualization strategies to help guide surgeons, evaluate the technology in an in vivo study, and validate the technology intraoperatively. By the end of this program we intend to have developed a low-cost, single use probe that can be deployed in a multi- center clinical trial to evaluate the efficacy of this technology for intraoperative surgical margin assessment.
Gauging electrical properties of surgical margins during tumor resection procedures has the potential to alert surgeons to regions of cancer not fully extracted and subsequently reduce the number of positive surgical margins which are significantly correlated with cancer recurrence. The intraoperative electrical property sensing/imaging probe and the visualization tools proposed here will provide an accurate, rapid, and cost- effective method for gauging these surgical margins for multiple cancer types. We will explore this technology in the context of prostate cancer surgery with the expectation that this will further advance the study of electrical property signatures of normal and diseased tissue in vivo and help to translate this technology to the clinic.
