Precision Image-Guided Ultrasound Ablation of Brain Tumors: A Longitudinal Pre-Clinical Study using a Newly Developed Platform

Most traditional methods for treating tumours, such as radiation therapy or even traditional focused ultrasound, work by heating the tumour until the cancer cells die. Focused ultrasound therapy without heating, however, is a relatively new method of treating tumours. It works by inducing bubbles within the tumour itself so cancer cells are mechanically ripped apart into small fragments when the bubbles collapse. This has numerous advantageous over traditional methods such as higher precision, non-ionizing characteristics, and less peripheral damage. Recent studies have also shown that the immune system has a much stronger and more positive response to this therapy, helping to eliminate any cancer cells the treatment might have missed. Although other groups have used this technology for treating tumours using large devices from outside the body, we have developed the first endoscopic version of the technology that can treat tumours with a small pencil sized probe during small access surgeries. Such a device is particularly well suited for neurosurgeries where surgeons need to resect tumours through a small access hole drilled into the skull. The current gold standard in neurosurgery is to disrupt tumours using a device that resembles pencil sized jack-hammer. These miniature jack-hammers lack precision when they destroy tissue upon contact, and also have very limited guidance from any imaging systems during surgery. Not only does the therapeutic device that we have developed have much higher precision, but we have also built in very high-resolution ultrasound imaging guidance into the device itself. The primary goal of the proposed project will be to demonstrate the technology by targeting and treating brain tumours in mice. We will quantify the lengthening of life span and the immune system's response. A second project goal is to demonstrate the amplification of the immune system's response by combining the ultrasound therapy with a common immunotherapy.