Frameless stereotaxy and interactive neurosurgery with the ISG viewing wand.

Preliminary experience with the ISG wand for frameless stereotaxy is presented. The wand is a multijointed mechanical arm with a range of 25 inch radius sphere. The arm has a analog/digital hybrid transducers to locate the spatial position of the probe tip. The real time displays of triplanar 2D images with an optional 2D/3D image helps in surgical planning and interactive surgery. Seventeen patients underwent neurosurgical procedures with the help of wand. The wand was used to place minimal craniotomies, localise the brain-tumour interface and excise the lesions. The wand had an accuracy of 1.8 mm (SEM +/- 0.36 mm) in localising the lesions. Thus, the use of frameless stereotaxy has made easier and more precise surgical planning in several applications.