A Focused Ultrasound System for Tissue Volume Ablation in Deep Seated Brain Sites

A new intense focused ultrasound system operating in the transcutaneous mode has been constructed for study of its utility in the treatment of deep seated brain tumors in the human. In preparation for treatment the human will have surgical removal of an appropriate skull section and the o verlying t issues will be left to heal before starting the irradiation process. treatment will be done with CT scanning involving a rigid l ight weight skull fixation fixture which remains rigidly attached to the patient's skull for the CT scan as well as for the irradiation procedure. Once the lesion volume coordinates are determined and the patient is attached to the irradiation system the 1 MHz focused beam is automatically brought to an array of positions within the tissue volume. Each position is individually lesioned and the tissue volume ablated is constructed f rom a multiplicity of individual site lesions. Localization of a tumor site for