Many promising studies indicate that ultrasound-enhanced drug delivery vehicles can be used to locally delivery a drug to a region of interest, with ultrasound imaging used to define the region to be treated and to monitor the inflow of the delivery vehicle. In this project, we will specifically explore the development of ultrasound techniques to locally concentrate a chemotherapeutic drug within the brain, crossing the blood-brain barrier (BBB). This is a unique problem and is critically important as the survival time with primary and metastatic brain tumors is low. Chemotherapy has been unsuccessful in general, and surgical debulking of the tumor and radiotherapy extend the patient survival only by 6-12 months. New research studies have demonstrated that BBB permeability can be greatly increased for both hydrophilic and hydrophobic drugs through the application of systemic compounds that include bradykinin analogs and P-glycoprotein blockers. The disadvantage of the global increase in BBB permeability (produced by these drugs) is that the simultaneous application of chemotherapy at the desired concentrations can result in a severe neurotoxicity. Ultimately, by combining increased BBB permeability with local delivery of a chemotherapeutic to a region of interest, we hope to significantly increase the effectiveness of chemotherapy in brain tumors.