Cavitation in an antivascular cancer therapy setting

Abstract

Focused ultrasound in combination with circulating microbubbles is being widely investigated as a means to promote spatially targeted drug delivery. This approach has considerable potential in oncology for a range of therapeutic agents. At sufficiently high pressures, above those typically employed in drug delivery, tumor microvessel damage can be induced to an extent that leads to perfusion shutdown and subsequent ischemic tissue necrosis. This approach is often referred to as antivascular ultrasound (AVUS), which has been shown in preclinical work to be capable of enhancing the effects of radiation therapy, antiangiogenic therapy, chemotherapy, and immunotherapy. At present, the mechanisms of AVUS are not well established. It is important to gain a more detailed understanding of the bubble–microvessel interactions that lead to perfusion shutdown, along with the cavitation signatures associated with these behaviors to enable the rational development of effective cavitation based control methods. This talk will provide a brief overview of AVUS therapy in oncology and highlight recent efforts employing two-photon microscopy, high speed optical imaging, and acoustic emission monitoring to gain insights into bubble behavior within small channels and in vivo microvessels under AVUS exposure conditions.