The accuracy of the placement of depth electrodes in epileptic patients with different stereotactic methods

• Grant number: 15/09476-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2015
• End date: November 05, 2017
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Ricardo Silva Centeno
• Grantee: Otávio Augusto Barbosa Breda
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The development of new technologies in neuronavigation opens a new era of epileptic patients surgical treatment. The combination of information obtained from functional and anatomic images combined with new stereotactic methods and robots provides a better accuracy and security to several neurosurgical procedures. The placement of depth electrodes is traditionally performed by the frame-based stereotaxy, which is considered the gold-standard method and which has its efficacy already reported by the literature. Under this perspective, news studies have been demonstrating the feasibility and accuracy of new methods, mainly the frameless stereotactic system.Objects: This project aims the assessment of the accuracy and security of the placement of depth electrodes by the frameless system, in comparison with the traditional frame-based method, reporting both methods' advantages and disadvantages. Methods: In this project, 20 patients will be selected and randomized in two groups to undergo the placement of depth electrodes: one of them through the frame-based method and the other through the frameless stereotactic system. Three accuracy measures will be calculated: entry deviation, target deviation and depth deviation, which will be considered successfully placed whether under a 3mm safe margin. Intra- and post-surgical complications, the electrode placement time, the total surgery time and the total hospitalization time for monitoring will also be assessed and reported.Results: The new frameless method is expected to have similar accuracy and complication rates, when compared to the traditional frame-based method, as well as the accuracy measures are expected not to exceed the 3mm safe margin. Moreover, the frameless system is expected to stand out over the traditional one, as it is more confortable to the patient, provides better autonomy to the surgeon, permits a better integration with the neuronavigation system, thus increasing the accuracy and reducing the placement time and complication rate of the procedure.