Precisely Targeted Tumor Biopsy and Marking under CT-Fluoroscopy

Abstract

An innovative imaging procedure, computed tomographic (CT) fluoroscopy, was recently developed by Katada and Toshiba Medical Corporation in Japan [1,2]. This procedure permits sequential display of computed tomograms in real time. CT-fluoroscopy has been found to be extremely useful for real-time monitoring, which ensures the safety and accuracy of invasive techniques such as punctures in the neurosurgical held [3]. We recently, attempted targeted needle biopsy at three points, the subcortex near the lesion and the lateral side and center of the lesion, under CT-fluoroscopy. We then attempted to precisely place a marker at the inner border of the lesion near the internal capsule. A round mini-coil was used as the marker. Two weeks later we succeeded in extensively resecting the tumor lesion without producing motor weakness because the marker's shadow on an ultrasonic image allowed navigation to the bottom of the lesion very precisely by showing where the eloquent area was located. A neuronavigation system using preoperative images was used simultaneously. There was a difference of 10 mm between the point indicated with the navigator and the actual position of the marker. This difference is considered to reflect brain shift caused by intraoperative leakage of cerebrospinal fluid. Thus, the computer-aided neuronavigation system appears to require a feedback technique for intraoperative brain shift that would enhance precision, reliability, and safety. In this respect, CT-fluoroscopy combined with intraoperative CT is considered to play a potentially very important role.