The purpose of this research study is to determine the effects bevacizumab (the study drug) combined with Optune (the study device) tumor treatment field therapy has on meningiomas. Bevacizumab is considered investigational because the US Food and Drug Administration (FDA) has not approved its use for the treatment of meningiomas. The study drug is a medication that blocks the growth of new blood vessels. It is thought that the study drug may interfere with the growth of new blood vessels and therefore might stop tumor growth, and possibly shrink the tumor by keeping it from receiving nutrients and oxygen supplied by the blood vessels. Optune is also considered investigational because the US FDA has not approved its use for the treatment of meningiomas. Optune is a device that the patient will wear and use for at least 18 hours of each day. It delivers alternating electrical current to the patient’s brain tumor and by doing so interrupts a process called mitosis. Mitosis needs to occur in order for cell division to occur and allows tumors to grow. By slowing this process, we hypothesize that meningioma growth may also be slowed.