Ultrasonically-Induced Vaporization of Perfluorocarbon Droplets for Occlusion Therapy of Breast Cancer

Abstract

Abstract : A technique termed Acoustic Droplet Vaporization (ADV) has been developed in which ultrasound triggers small liquid droplets to form gas bubbles in arterial blood. The droplets are injected intravenously thus eliminating catheterization. Droplets vaporize into bubbles at the desired location in the body by applying ultrasound through the skin. Using renal occlusion as a model blood flow following ADV in the renal artery was reduced by greater than 90% in the renal cortex and more than 60% in the medullary tissues. An average organ perfusion reduction of >70% was achieved using ADV. The studies performed represented the most extensive investigation of flow occlusion by ADV to date. The control kidney on the contralateral side showed a maximum decrease in regional blood flow of 18% relative to the pre- ADV baseline. Image-based hyper-echogenicity from ADV of IA injections was monitored for approximately 90 minutes and cortex perfusion was reduced by >60% of its original value for more than 1 hour. This could be enough time for the onset of cell death and possible tumor treatment via ischemic necrosis. Moreover currently used radiofrequency tissue ablation-based tumor treatment could benefit from ADV due to the decreased heat loss via vascular cooling.