Intraoperative Use of Digital Volume Tomography (DVT) for Navigation-Assisted Resection of the Anterior and Lateral Skull Base Pathologies

Objective: To optimize the accuracy of intraoperative navigation for tumor resection in the anterior and lateral skull base, we have used the intraoperative imaging (xCAT scanner, Xoran Technologies, Inc., Ann Arbor, Michigan, USA).

Design: Prospective study.

Material and Methods: Reference markers were fixed into the bone (osteosynthesis screws) in five cases or attached to a maxillary splint, which was carried during the intraoperative imaging before the surgery, in six cases. The procedure was carried out isotropically with a resolution of 0.4 mm with the VectorVision2 system (BrainLAB, Feldkirchen, Germany).

Results: The reference marker was attached at the Mayfield clamp or fixed directly to the skull. Navigation was checked by using the identification of tumor margins and anatomical landmarks (transition sphenoid sinus front wall to the nasal septum, on bony prominent structures in the sphenoid sinus and the temporal bone) and cannot therefore be stated in exact figures; however, the surgeons pointed out that the accuracy was very good: the image of the screen to be extended with the pointer anatomical site was always represented exactly, so that the overall accuracy of the system intraoperatively estimated total of less than 1 mm.

Conclusion: An intraoperative imaging for navigation device can provide accurate intraoperative precision and thus can be used as a reliable intraoperative diagnostic tool.