3D Stereo Aids to Stereotactic Cancer Brain Surgery

It is very important to develop a simple, safe, and reliable system for coordinating cancer brainsurgery while it is actually being done. This is true for simple stereotactic techniques and also true forresections. Currently there are a number of devices that allow integration of pre-operative stereotacticcoordinates to intra-operative use. This allows tumor localization and a high degree of accuracy, at leastat the beginning of surgery. The major problem is that as the surgery proceeds, and as the brain eitherrelaxes or swells, and as some tumor is removed, the coordinates change. In this regard, it would benice to have ultrasound guidance during the operation which was initially coordinated with stereotacticinformation derived from 3-D stereo computer reconstruction with prior MRI or CT scans in stereotacticspace. But, in fact, the use of ultrasound is probably the only way of carrying out this real-time, on-lineguidance, since the use of both CT and MRI for this purpose would be unfeasible froth both a physicaland financial viewpoint. In addition, CT would involve x-ray exposures, and MRI presents a strongmagnetic field and would require the use of only non-magnetic metallic instrumentation. On the otherhand, the ultrasound probe can easily be placed on the brain, either through an adjacent hole in the skullor through the surgical brain access.