Primary osteogenic sarcoma of the brain

✓ The authors report a case of primary osteogenic sarcoma of the brain. Negative autopsy findings, complete bone radiographs, and bone-scanning techniques were consistent with a primary tumor focus in the right temporoparietal region of the brain. The authors suggest an origin from a primitive multipotential mesenchymal cell.</jats:p

Posttraumatic bilateral middle cerebral artery occlusion

✓ The authors report a case of bilateral posttraumatic middle cerebral artery occlusion. Previously reported unilateral cases are reviewed and possible pathophysiological mechanisms disscussed.</jats:p

Computerized three-dimensional stereotaxic removal of small central nervous system lesions in patients

✓ The authors describe the results of their recently reported computer-based stereotaxic surgical technique for the identification, enhancement, three-dimensional reconstruction, localization, and removal of small central nervous system lesions. This technique has been applied to patients with various types of central nervous system pathology, and representative cases are reported.</jats:p

Development of a Protocol for Photoradiation Therapy of Malignant Brain Tumors: Part 1

Abstract The successful application of phototherapy to subcutaneous tumors has suggested that a similar procedure should be developed for treating gliomas. As a result, attempts are being made to determine a set of conditions that would optimize the destruction of tumor cells while minimizing injury to surrounding brain tissue. To initiate this task, we developed a novel assay method to assess the amount of phototoxicity induced in normal brain by light exposure of mice treated with hematoporphyrin derivative (HPD). The application of this procedure demonstrated that a sufficient amount of HPD was retained in brain tissue, even 72 hours after injection, to cause severe cerebral damage in light-treated mice.</jats:p

Development of a computerized microstereotaxic method for localization and removal of minute CNS lesions under direct 3-D vision

✓ The authors describe a novel stereotaxic method for the removal of minute lesions of the central nervous system (CNS). With the development and refinement of computerized tomography (CT), such small lesions can be detected by noninvasive (x-ray) scanning with computer processing of the data. Using a G E 7800 scanner system and a PDP 11/45 computer, data processing of various kinds is possible. Multiple computer programs have been developed to enhance regions of interest on CT scans by magnification, three-dimensional reconstruction, and digital processing. These data are then used to calculate a stereotaxic approach to a CNS lesion. A head fixation system has been devised to enable information transfer from a CT scan to the stereotaxic surgical system. Newly developed instruments are mounted on a micromanipulator for guidance at the operative site. These include stereo endoscopes with xenon arc illumination, a tissue expander for exposing the operative area, a radiation tracer probe, a rotary extractor, and instruments for operating and removal of blood from a small intracerebral hemorrhage. The micromanipulator for guiding the tactical instruments is, in turn, mounted on a stereotaxic guide mechanism which accurately defines all areas of the cranium in three-dimensional coordinates. The combination enables the site of the lesion, the three-dimensional coordinates of which have been located by CT scan, to be accurately approached by the stereotaxic guide/micromanipulator assembly.</jats:p