RecruitingDevice studyExtracellular Impact of Ultrasound-induced Blood-brain Barrier DisruptionThis study seeks to determine the impact of focused ultrasound (FUS) on the composition of the tumor extracellular microenvironment. Researchers will evaluate regions that are very abnormal, as well as regions that have less evidence of disease. A sub-portion of each of these areas will be targeted by focused ultrasound. Microdialysis catheters will then be placd into each region that has and has not been exposed to FUS (total of 4 catheters) to determine how FUS impacts the the brain and tumor extracellular metabolome, including concentration of routine drugs systemically administered prior to, and during surgery. Researchers hope that this information will help reveal the relative contribution of blood-derived compounds to the tumor microenvironment. If successful, microdialysis could be leveraged in the future to simultaneously evaluate pharmacokinetic and pharmacodynamic impacts of future candidate therapies, including those delivered with the aid of FUS.