OS11.6.A A COMPREHENSIVE FRAMEWORK FOR INTRAOPERATIVE MAPPING AND MONITORING, AND PERIOPERATIVE NEUROLOGICAL, LINGUISTIC, AND OUTCOME ASSESSMENT IN GLIOMA RESECTION: CONSENSUS RECOMMENDATIONS FROM THE PIONEER CONSORTIUM AND RANO RESECT GROUP

Abstract BACKGROUND In adult patients with diffuse glioma, greater extent of resection is associated with longer overall and progression-free survival. Intraoperative mapping and monitoring techniques are essential to safely achieve maximum resection identifying and preserving functional areas during surgery. Despite widespread use, there remains a lack of consensus on how and when these techniques should be applied, how intraoperative decisions should be made, or how to systematically evaluate neurological, language, cognitive, and functional outcomes in the perioperative context. This variability contributes to suboptimal outcomes, hinders uniformity across multicenter studies, and limits comparability of reported results. MATERIAL AND METHODS Two working groups from the PIONEER Consortium (Personalized Interventions and Outcomes in Neurosurgical Oncology Research) and the RANO (Response Assessment in Neuro-Oncology) resect group formed an interdisciplinary task force with experts from the fields of surgical and medical neuro-oncology, neuroanesthesia, neurolinguistics, and neuropsychology. The goal was to develop an expert-driven framework to standardize intraoperative mapping and monitoring strategies as well as perioperative outcome assessment in glioma surgery. RESULTS A core group of 25 representatives of the PIONEER Consortium and RANO resect group identified key domains based on expert consensus and drafted initial recommendations for best practice guidelines. These were reviewed and refined by 45 external experts using a two-staged eDelphi process. Recommendations rated as “critical importance” by ≥ 70% of the external raters were accepted. The final framework provides consensus recommendations across seven core domains: (I) indications, settings, and techniques for awake and asleep mapping and neuromonitoring, (II) intraoperative decision making to maximize safe resection, (III) patient selection criteria for intraoperative mapping and monitoring, (IV) neuroanesthesiological strategies, (V) perioperative neurolinguistical and neuropsychological aspects, (VI) assessment of neurological outcome, and (VII) assessment of overall functioning and quality of life. CONCLUSION These joint PIONEER-RANO recommendations represent the first international consensus framework integrating intraoperative mapping and monitoring strategies with standardized perioperative function assessment in glioma surgery. By consolidating multidisciplinary expertise, this framework addresses a critical gap in current practice by offering neurosurgeons a structured approach to optimize resection strategies while preserving function. Beyond enhancing individual patient outcomes, it lays the foundation for greater consistency across institutions to facilitate multicenter collaboration and advancements in surgical neuro-oncology.