SURG-17. 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

BACKGROUND In diffuse glioma patients, greater extent of resection is associated with longer survival. Intraoperative mapping and monitoring are essential to maximize safe resection by identifying and preserving functional areas. Despite widespread use, consensus is lacking 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. This variability contributes to suboptimal outcomes, hinders uniformity across multicenter studies, and limits comparability of 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 in surgical and medical neuro-oncology, neuroanesthesia, neurolinguistics, and neuropsychology. The goal was to develop a consensus framework to standardize intraoperative mapping and monitoring strategies and perioperative outcome assessment in glioma surgery. RESULTS A core group of 25 representatives from the PIONEER Consortium and RANO resect group identified key domains and drafted intitial recommendations. These were reviewed and refined by 45 external experts using a two-stage eDelphi process. Recommendations rated “critical importance” by ≥70% of external experts were accepted. The final framework provides consensus recommendations across seven domains: (I) indications, settings, and techniques for awake/asleep mapping and monitoring, (II) intraoperative decision making, (III) patient selection criteria, (IV) neuroanesthesiological strategies, (V) perioperative neurolinguistic and neuropsychological aspects, (VI) neurological outcome assessment, and (VII) overall functioning and quality of life assessment. CONCLUSION These joint PIONEER-RANO recommendations represent the first international consensus framework integrating intraoperative mapping and monitoring with standardized perioperative function assessment in glioma surgery. By consolidating multidisciplinary expertise, this framework fills a critical gap by offering neurosurgeons a structured approach to optimize resection while preserving function. This improves patient outcomes and enables consistency to facilitate multicenter collaboration in surgical neuro-oncology.