SURG-21. A CROWDSOURCED CONSENSUS ON SUPRATOTAL RESECTION VERSUS GROSS TOTAL RESECTION FOR ANATOMICALLY DISTINCT PRIMARY GLIOBLASTOMA

Abstract

Abstract Gross total resection (GTR) of contrast-enhancing tumor is associated with significantly increased overall survival in primary glioblastoma (GBM). Even when achieved, recurrence is likely, in part due to malignant cells infiltrating outside enhanced regions. Subsequently, there has been increasing interest in performing supratotal resections (SpTRs) for GBM. Published results have varied in part due to a lack of consensus on the definition of SpTR in GBM and its appropriate use. A crowdsourcing approach was used to survey 21 academic neurosurgical oncologists representing 13 health systems nationwide. Participants’ demographics including fellowship training status, years of experience, and operative volume with various techniques was collected. Participants were presented with 11 definitions of SpTR from published, peer-reviewed studies and asked to rate the appropriateness of each definition. Subsequently, participants reviewed T1-weighed post-contrast and FLAIR MR imaging videos in the axial, coronal, and sagittal planes for 22 GBMs. Participants were asked to assess eloquence of the tumor’s location, perceived equipoise of enrolling patients in a randomized clinical trial comparing GTR to SpTR, and their own personal surgical treatment plans. Most neurosurgeons surveyed (n=18, 85.7%) agree or strongly agree that GTR plus resection of some non-contrast enhancement is an appropriate definition for SpTR. Overall, there was only moderate inter-rater agreement, measured using sample variance and the index of qualitative variation, regarding eloquence, equipoise, and personal treatment plans. Neurosurgeons who performed more than 10 SpTRs for GBMs in the past year were more likely than counterparts to recommend it as their personal treatment plan (p< 0.005). Anterior temporal and right frontal GBMs were considered the best randomization candidates. We established a consensus definition for SpTR of GBM and identified anatomically distinct locations deemed most amenable to SpTR. These results will be used to plan prospective trials further investigating the potential clinical utility of SpTR for GBMs.