P11.04.B ASSESSMENT OF TUMOR ELOQUENCE IN GLIOMA RESECTIONS: A SYSTEMATIC REVIEW

Abstract

Abstract BACKGROUND Tumor location and eloquence are two crucial factors when deciding on the optimal surgical strategy in glioma management. Consensus is currently lacking on the assessment and definition of eloquent areas. This systematic review aims to evaluate the existing definitions and assessment methods of eloquent areas used in current clinical practice. MATERIAL AND METHODS A computer-aided search of Embase, Medline (OvidSP), and Google Scholar was performed to identify relevant studies. This review includes articles describing preoperative definitions of eloquence in the study’s Methods section. These definitions were compared and categorized by anatomical structure. Additionally, various techniques to preoperatively assess tumor eloquence were extracted, along with their benefits, drawbacks and ease of use. RESULTS This review covers 98 articles including 12,714 participants. Evaluation of these studies indicated considerable variability in defining eloquence. Categorization of these definitions yielded a list of 32 brain regions that were considered eloquent. The most commonly used methods to preoperatively determine tumor eloquence were anatomical classification systems and structural MRI, followed by DTI-FT, functional MRI and nTMS. CONCLUSION None of the definitions or techniques to define eloquence described in the articles are entirely satisfactory as an objective, quantifiable, preoperative factor in glioma treatment and surgical decision-making. Therefore, we propose the development of a new, easily applicable and interpretable anatomical preoperative grading system to assess tumor eloquence. This may aid neurosurgeons in their perioperative decision-making to improve surgical outcomes on an individual patient level and to facilitate the execution and interpretation of multicenter studies.