No clinical protocols are routinely used to intraoperatively assess surgical margin status during prostate surgery. Instead, margins are evaluated through pathological assessment of the prostate following radical prostatectomy (RP), when it is too late to provide additional surgical intervention. Positive surgical margins (PSMs) are indications for disease recurrence and suggest noxious adjuvant or salvage therapies. Between 10,000 and 40,000 men each year are diagnosed with recurrent prostate cancer due to cancer cells remaining following RP. Clearly, an intraoperative device able to assess surgical margin status has the potential to provide immediate impact to patient care. Significantly different electrical property signatures have been observed between benign and malignant prostate tissues, and we hypothesis that gauging these properties intraoperatively has the potential to provide clinically relevant information regarding surgical margin pathology.
We aim to take the significant step of translating our extensive laboratory experience to the development of an intraoperative device to assess surgical margin status based on these electrical properties. We propose constructing an EIS probe to sense and image at near microscopic resolution the prostate and surrounding tissues during RP in an effort to provide surgeons with real-time assessment of margin pathologies. A robot- assisted minimally invasive approach for RP is employed at our Institution and we plan to design this probe to interface with this system. Surgical visualization is provided through an endoscopic optical system which we aim to use for registering the measured electrical properties to the precise anatomic locations probed. The probe and visualization tools will be coupled into an integrated intraoperative system which will provide a surgeon control of probe positioning and measurement acquisition. The probe will be evaluated on a series of ex vivo human prostate specimens and the fully integrated system will be employed intraoperatively in a series of patients undergoing RP procedures. Our long-term vision is to develop this tool so that the electrical properties of prostate will be sensed around sites most often noted for positive surgical margins including the apical margin, base margin, and neurovascular bundle margin (when nerve sparing procedures are performed). The new intraoperative information acquired by sensing these surgical margins has the potential to reduce the number of PSMs which will 1) reduce the mortality rate associated with prostate cancer recurrence, 2) reduce the morbidities associated with adjuvant and salvage therapies in patients who would have had positive surgical margins, and 3) reduce the financial burdens to the patient and healthcare providers associated with cancer recurrence.
Gauging electrical properties of surgical margins during radical prostatectomy 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 prostate 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. Overall, this will further advance the study of electrical property signatures of normal and diseased prostate in vivo and help to translate this technology to the clinic.
|Halter, Ryan J; Kim, Young-Joong (2014) Toward microendoscopic electrical impedance tomography for intraoperative surgical margin assessment. IEEE Trans Biomed Eng 61:2779-86|