Development platform for acoustoelectric impedance tomography in internal radiation therapy

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Breast and prostate cancers are the most common invasive cancers amongst Canadian women and men, respectively. Currently, 1 in 7 Canadian men will develop prostate cancer during their lifetime and 1 in 27 will die from it; a ratio of 1 death per 4 diagnoses, similar to the ratio observed for breast cancer in women. Cervical cancer is another major health problem amongst Canadian women with 1550 cases diagnosed and an estimated 400 deaths in 2017. Internal radiation therapy is a common minimally invasive treatment for these conditions. In this procedure, long needles are inserted percutaneously into the tumour under ultrasound image guidance to permanently implant radioactive seeds whose emitted radiation treats the cancer cells as it decays over the course of several weeks. It is well-recognized that ultrasound imaging lacks the resolution required to visualize and delineate cancerous structures and abnormalities in internal radiation therapy. In fact, physicians can target hypoechoic regions but it has been reported that up to 40% of these cancers are invisible under ultrasound, making tumour targeting extremely difficult. ******We are developing a new imaging method for internal radiation therapy. In our approach, needles are instrumented with tiny electrodes that are able to measure the electric conductivity of the tissue and used to create tomographic images of the cancerous tissue from within it, and that with much higher contrast than that of ultrasound images. Focused ultrasound beams are then applied to the tissue to alter the local electrical conductivity, which in turn changes the tomographic images. This allows extracting more information about the tissue from data that has been enriched by coupling electric impedance tomography and localized acoustic pressure. The result is a set of images of the inner tissue that combines the contrast of impedance tomography and the resolution of ultrasound images. It has the potential to image tissue inclusions and lesions that are otherwise not visible in traditional ultrasound imaging. More accurate imaging will make treatment for leading forms of cancer more efficient and enable internal to be considered for other types of cancers. ******The continuity of our research requires immediate access to an ultrasound machine with an open architecture, arbitrary waveform generation, and radio frequency (RF) data acquisition capabilities, and a means of tracking surgical tools in tissue. In this proposal, funding is requested to acquire a research ultrasound machine with an open architecture and an electromagnetic tool tracking system that are needed to upgrade our experimental setup. Combined, the equipment will form a state of the art research platform for the development of a new imaging method for cancer diagnosis and treatment. **