Grant: Research Tools and Instruments

Unlike most glandular cancers, prostate cancer (PCa) is often not visible under ultrasound (US) imaging. When intermingled with healthy tissue, early stage PCa is invisible in US, and most observable lesions do not require treatment. Yet, most PCa diagnostic and treatment options rely on US to locate and sample suspicious lesions. Low tumour visibility often leads to uncertain biopsy results, mis- and overdiagnosis, and poor radiation control over suspected lesions. A new method to detect and delineate lesions in US will improve PCa diagnosis and management, and unlock treatment options that are not feasible with current technologies. Supported by NSERC, NFRF, and Cancer Research Society grants, we are pioneering a new US-based imaging modality that will make cancerous lesions more visible. The research combines dieletric spectroscopy-capable custom-made biopsy needles that identify the tissue around the needle tip in real-time, with US modulation of the tissue's impedance to create a tomographic image of the tissue. The images can then be overlaid on top of US to detect and visualize small lesions. While we have made substantial breakthroughs in developing this technology, two major factors are limiting the progress of our research: First, image reconstruction requires the recovery of a 1-2 MHz noisy nV signal from a 1 kHz mV carrier. Extracting this tiny signal buried in noise and harmonics in realistic experimental scenarios is not feasible with our equipment. Second, PCa manifests in the dieletric properties of the tissue more prominently above 20 GHz. However, our vector network analyser (VNA) is limited to 6 GHz. Thus, we required access to 1) a 5-MHz lock-in amplifier, and 2) a 44-GHz portable VNA with an integrated dielectric characterization probe. A lock-in amplifier is designed to recover a signal of reference from a background with overwhelming levels of noise. It will allow us to capture the required signals with much higher accuracy than what we can achieve with our in-house made equipment. The requested VNA will increase the frequency range of our experimental setup 7 fold, thereby capturing fundamental information needed to detect PCa. It will also support the development of higher frequency probes that can detect smaller lesions and more subtle manifestations of PCa. The equipment is also urgently needed in an experimental trial at the Ottawa Hospital on ex-vivo prostatic tissue resected after radical prostatetcomy. Rather than another incremental contribution to the field of cancer imaging, the requested equipment will support a fundamentally new approach where needles will deliver information about the tissue directly from within it. This long-overdue paradigm shift has the potential to lead to accurate lesion sampling, decrease uncertainties in the diagnostic pathway, and provide new data to guide PCa treatment plans and improving health outcomes.