Po-05-104 feasibility study of single day simulation- free cardiac radioablation workflow with a porcine model

Cardiac radioablation (CRA) is a novel and expanding treatment option for patients with ventricular tachycardia (VT). CRA is a complex process involving interdisciplinary collaboration and requires multiple days between patient imaging and treatment delivery. For patients with active VT, this wait is difficult. Improving efficiency and standardization of CRA workflows is critically important for controllably implementing and assessing this novel treatment approach for research and clinical deployment. We hypothesized that by leveraging state-of-the-art technology within radiotherapy, key steps in the treatment planning and delivery process may be condensed to a single session on the treatment machine. Investigate the feasibility of CRA treatment in a single day, simulation-free workflow with a porcine model. Under an approved animal studies protocol, CRA was performed using a porcine model. In this workflow the animal was brought to radiation oncology under anesthesia under the supervision of a veterinary care team and was placed in the decubitus position on a dedicated research ring gantry linear accelerator platform. The ventilation rate of the animal was set to 8 breaths per minutes. A 6 second cone beam computed tomography scan was completed during exhalation while IV contrast was simultaneously administered. Images were reviewed by a radiation oncologist, medical physicist, and electrophysiologist. Organs at risk as well as the site of the VT target site were contoured. A radiation treatment plan was developed on this data set and reviewed by the treatment team. A CBCT was repeated to confirm alignment of the animal. The animal then received CRA to 25 Gy to planning target volume (PTV) in a single fraction. Simulation-free cardiac radioablation was successfully delivered to a pig in a single session using a commercially available ring gantry linear accelerator. This study demonstrates feasibility of conducting a simulation-free preclinical animal study of CRA using a commercially available linear accelerator and ultimately moves the field closer to same-day cardiac radioablation.