This application addresses broad Challenge Area (06): Enabling Technologies and specific Challenge Topic, 06-EB-101: Development of minimally invasive image-guided systems. The primary goal of this program is to couple already existing technologies into a multi-modal image-guidance system to improve the accuracy of prostate biopsy and disease staging. Currently employed transrectal ultrasound (TRUS)-guided prostate biopsy procedures miss up to 30% of all cancers and are not able to accurately gauge the extent and aggressiveness of the disease. Recent studies by our group have shown that significant electrical property differences existing between malignant and benign prostate tissues provide levels of contrast exceeding those of routinely employed sensing and imaging technologies including TRUS. We propose to integrate electrical property imaging and sensing devices we have developed into a standard clinically accepted TRUS-guided biopsy procedure to improve prostate cancer detection and staging. In two separately funded projects, we have developed 1) an electrical impedance imaging (EII) device that couples a flexible array of electrodes directly to a clinical TRUS probe to provide co-registered ultrasound (US) and electrical property images and 2) an electrical impedance spectroscopy (EIS) sensor integrated into a standard 18-gauge prostate biopsy (Bx) needle to permit sensing of internal prostatic electrical properties in tandem with tissue core extraction. We hypothesize that by coupling these modalities for use during image-guided prostate biopsy procedures a clinician will have enhanced focal lesion detection and identification and improved assessment of disease extent and aggressiveness within the prostate. During this program, EII-TRUS and EIS-Bx data acquisition will be synchronized, and the intra-prostatic electrical properties gauged with EIS-Bx will be incorporated into the algorithm used to reconstruct electrical property images from EII. This algorithm will be implemented on high speed graphical processing units to provide near real-time imaging for clinical deployment. In an effort to rapidly translate this technology to the clinic, the multi-modal image-guidance system will be used during a series of routine biopsy procedures at our institution in order to assess the clinical potential imaging the electrical properties of prostate provides. Because these devices were designed to minimally augment already existing and clinically accepted instruments, are relatively inexpensive (<$10k for an EII system and <$100 for each EIS-Bx device, production quantities), and are able to identify malignant prostate with a high degree of sensitivity and specificity, this technology has the potential of being easily translated to and accepted by the clinic for the benefit of men suspected of having prostate cancer. We expect that by the end of this two-year program we will be in a position to conduct a much larger clinical trial evaluating the added benefit this system provides to routine prostate biopsy. This project capitalizes on our group's extensive clinical experience in electrical impedance sensing and imaging.
Current clinical practices using trans-rectal ultrasound (TRUS) imaging to guide prostate biopsy unfortunately miss up to a third of all cancers and do not accurately identify the clinical significance of the disease. The tissue-structure dependent electrical properties of prostate are significantly different in cancer and normal tissue and provide levels of contrast that far exceed those of TRUS.
We aim to image these properties during biopsy procedures in order to provide more accurate real-time clinical assessment of cancer content within the prostate and evaluate the gains achievable for disease detection and staging when these electrical properties are sensed.
