Abstract: A destructive heat lesion is placed in any location in the brain. A patient's head is secured within a stereotactic frame. After a high resolution CT scan and angiogram or MRI, data is incorporated and analyzed by a computer. This information is then resynthesized and projected as a video image on a screen facing the surgeon. A small magnetic object, perhaps a ball, is inserted into the patient's head via a burr hole drilled through the patient's skull. Using, real time fluoroscopic data superimposed on the computer image of three-dimensional structures, the surgeon is able to control and manipulate the object through the patient's soft brain tissue to a position next to or inside of the tumor area. An energy beam is then fired at the object, causing the more heat efficient object to destroy the brain tumor area. This procedure is repeated until the entire tumor is eradicated by the highly localized hyperthermia.