Computer-assisted stereotaxic laser resection of intra-axial brain neoplasms

Abstract

Computer interpolation of stereotaxic computerized tomography (CT) scanning data allows the transposition of a tumor volume in stereotaxic space. A stereotaxically directed and computer-monitored CO2 laser is then utilized to vaporize that volume as the surgeon monitors the position of a cursor representing the laser beam against planar contours of the tumor displayed on an operating room computer monitor. Computer-assisted stereotaxic laser microsurgery provides precise three-dimensional control for aggressive resection of deep-seated tumors from neurologically important areas with acceptable postoperative results. Thus, a significant cytoreduction can be achieved in addition to providing a tissue diagnosis and internal decompression. The authors report 83 computer-assisted stereotaxic laser procedures for tumor excision in 78 patients. The tumors were located in the thalamus/basal ganglia in 15 patients, ventricular system in five, corpus callosum in four, brain stem in three, and deep and centrally in the hemispheres in 51. Histologically, there were 26 glioblastomas, seven grade III astrocytomas, 14 grade II astrocytomas, 14 metastatic tumors, nine vascular lesions, and eight miscellaneous lesions. Resection of these subcortical lesions was confirmed by postoperative contrast-enhanced CT scanning. Neurological examinations performed 1 week after the 83 procedures revealed that 48 patients had improved from their preoperative level and 23 were unchanged (12 were neurologically normal preoperatively). Twelve patients had an increase in a preoperative neurological deficit, three of whom died in the postoperative period: one from infection, one from pulmonary emboli, and one from brain-stem edema. The average survival period (37.6 weeks) of patients having glioblastomas treated by this technique and irradiation was no different from that of patients having glioblastomas in more favorable locations treated by conventional surgery and irradiation. Patients with circumscribed lower-grade astrocytomas did better in terms of morbidity and completeness of resection than those with infiltrative neoplasms. Other circumscribed lesions, such as metastatic tumors, vascular lesions, and intraventricular tumors, were easily resected by the technique described.

Augmented reality visualization for laparoscopic surgery

“…The first medical application of AR was to neurosurgery [Kelly86]. Similar systems [Lorensen93,Grimson95] have been developed independently.…”

Neurosurgical considerations in supratentorial low-grade gliomas: experience with 175 patients

“…For planning surgical procedures, such interactive analysis provides a new level of flexibility greater than that previously reported. [33][34][35] The ability to generate detailed 3-D renderings at high speed is essential for the interactive exploration and planning sessions; the surgeon can view different approaches and different relationships of the lesions to vessels and cranial nerves and can use the planning process as an important preview of the surgery. Improvements on the system will facilitate the use of 3-D reconstruction to guide intraoperative navigation, allowing one kind of frameless stereotaxy.…”

Non-rigid Registration of Serial Intra-operative Images for Automatic Brain Shift Estimation

“…A number of methods have been developed for this purpose but until recently these have involved rigid body registration techniques. Although rigid body techniques have proven clinically useful, there is a body of literature that shows that brain deforms during the procedure [1,2,3]. When this is the case, rigid body transformations are not sufficient to register accurately pre-and intra-operative information.…”