The instant invention describes a surgical tool for providing cavitations, or void spots, within the interior of body regions. The surgical tool is constructed and arranged to penetrate almost all interior body regions in which formation of a cavity or void space is necessary for diagnostic or treatment purposes. The surgical tool comprises an insertable member receiving structure sized and shaped to receive one or more insertable devices. The interior lumen of the insertable member receiving structure allows the insertable device to slide and/or rotate relative to the insertable member receiving structure and vice versa. At least one insertable member is a cavity forming device which has a plurality of cavity forming members constructed and arranged with spring-like characteristics for traversing between a cavity forming position and a non-cavity forming position. Upon traversal back to the cavity forming position, the displacement members retain their cavity forming structural configurations.