PROJECT SUMMARY/ABSTRACT This SBIR Phase I application aims to investigate a novel intra-procedural feedback mechanism for microwave ablation (MWA) procedures used for the thermal treatment of localized cancer. Although MWA provides a minimally invasive, low cost, outpatient therapy that has comparable outcomes to the gold standard surgical resection for small tumors, local recurrence rates remain considerably higher for large tumors (> 3 cm diameter). Inadequate thermal dose delivery to the targeted tumor and failure to establish an adequate treatment margin is believed to be a primary cause of thermal ablation’s higher recurrence rates. While contrast-enhanced imaging with X-ray CT provides a means for verifying the ablation volume post-procedure, there are no techniques for monitoring the ablation zone and providing actionable information during the procedure. Incomplete ablation could result in disease recurrence and necessitate reperformance of the procedure, burdening patients and hospitals where the CT-suite is a capacity constrained resource. Alternatively, excessive thermal dose could inadvertently injure nearby healthy tissues and require additional medical intervention. Leveraging unique capabilities of the patented directional MWA (DMWA) applicator our team previously developed, we identified a new method which uses our applicators to both deliver treatment and act as sensors to track the status and estimate the completion of MWA procedures in real time. This innovation provides clinicians critical intra-procedural feedback and give confidence that they achieved the result they wanted and did not over- or under-treat while also preserving the integrity of the target organ and reducing the chance of collateral injury to other sensitive tissues. This innovation does not require significant changes to current clinical workflow or preclude continued use of post-ablation confirmation imaging. The overall objective of this R43 SBIR Phase I application is to show technical proof of concept for our proposed feedback method. The approach for our first specific aim includes development of a predictive coupled electromagnetic-heat transfer physics model of our feedback system using finite element method software tools. We will then construct an experimental apparatus to monitor and record the electromagnetic parameters utilized in our feedback system and conduct ex vivo benchtop experimentation to show proof-of-concept and refine our computer model. Our second specific aim includes an in vivo study in collaboration with our veterinary school to evaluate our feedback system in a clinical setting using post-procedure CT imaging and histopathology. Our long-term goal is to improve safety and effectiveness of MWA to expand patient access to minimally invasive, affordable, outpatient treatment of cancer.