Project Summary Integrated time nanosecond pulse irreversible electroporation (INSPIRE) is a minimally invasive treatment for inoperable solid tumors. This treatment uses ultrashort electrical pulses to destabilize the cell membrane and induce a tunable combination of necrotic and apoptotic cell death within a well-defined volume. The therapy is implemented by introducing one or more electrodes into the tumor then delivering a series of 500ns to 2000ns electrical pulses between an electrode and an external grounding pad. To enable treatment of tumors which occur near our around critical structures active temperature feedback is utilized to limit Joule heating and prevent deleterious thermal injury. Using a combination of ex vivo, in vivo, and computational results we hypothesize that INSPIRE will be a safe and effective treatment for the vast majority of inoperable tumors utilizing a single applicator approach and a compatible pulse generator capable of high voltage outputs when active temperature control is utilized to prevent off-target thermal injury. This proposal will leverage recent developments in high voltage power electronics to develop new instrumentation which is capable of safely administering these treatments in vivo. The safety, efficacy, and reproducibility of these treatments will be evaluated in a combination of in vitro, ex vivo, and in vivo models and the data generated in these studies will be utilized to optimize treatment planning algorithms and clinical applicators designs. The study will culminate with an in vivo study demonstrating the safety and efficacy of these treatments against spontaneous liver tumors in canine veterinary patients.