On the cutting edge of glioblastoma surgery:where neurosurgeons agree and disagree on surgical decisions

OBJECTIVE: The aim of glioblastoma surgery is to maximize the extent of resection while preserving functional integrity. Standards are lacking for surgical decision-making, and previous studies indicate treatment variations. These shortcomings reflect the need to evaluate larger populations from different care teams. In this study, the authors used probability maps to quantify and compare surgical decision-making throughout the brain by 12 neurosurgical teams for patients with glioblastoma. METHODS: The study included all adult patients who underwent first-time glioblastoma surgery in 2012-2013 and were treated by 1 of the 12 participating neurosurgical teams. Voxel-wise probability maps of tumor location, biopsy, and resection were constructed for each team to identify and compare patient treatment variations. Brain regions with different biopsy and resection results between teams were identified and analyzed for patient functional outcome and survival. RESULTS: The study cohort consisted of 1087 patients, of whom 363 underwent a biopsy and 724 a resection. Biopsy and resection decisions were generally comparable between teams, providing benchmarks for probability maps of resections and biopsies for glioblastoma. Differences in biopsy rates were identified for the right superior frontal gyrus and indicated variation in biopsy decisions. Differences in resection rates were identified for the left superior parietal lobule, indicating variations in resection decisions. CONCLUSIONS: Probability maps of glioblastoma surgery enabled capture of clinical practice decisions and indicated that teams generally agreed on which region to biopsy or to resect. However, treatment variations reflecting clinical dilemmas were observed and pinpointed by using the probability maps, which could therefore be useful for quality-of-care discussions between surgical teams for patients with glioblastoma

Quantifying eloquent locations for glioblastoma surgery using resection probability maps

OBJECTIVE Decisions in glioblastoma surgery are often guided by presumed eloquence of the tumor location. The authors introduce the "expected residual tumor volume" (eRV) and the "expected resectability index" (eRI) based on previous decisions aggregated in resection probability maps. The diagnostic accuracy of eRV and eRI to predict biopsy decisions, resectability, functional outcome, and survival was determined. METHODS Consecutive patients with first-time glioblastoma surgery in 2012-2013 were included from 12 hospitals. The eRV was calculated from the preoperative MR images of each patient using a resection probability map, and the eRI was derived from the tumor volume. As reference, Sawaya's tumor location eloquence grades (EGs) were classified. Resectability was measured as observed extent of resection (EOR) and residual volume, and functional outcome as change in Karnofsky Performance Scale score. Receiver operating characteristic curves and multivariable logistic regression were applied. RESULTS Of 915 patients, 674 (74%) underwent a resection with a median EOR of 97%, functional improvement in 71 (8%), functional decline in 78 (9%), and median survival of 12.8 months. The eRI and eRV identified biopsies and EORs of at least 80%, 90%, or 98% better than EG. The eRV and eRI predicted observed residual volumes under 10, 5, and 1 ml better than EG. The eRV, eRI, and EG had low diagnostic accuracy for functional outcome changes. Higher eRV and lower eRI were strongly associated with shorter survival, independent of known prognostic factors. CONCLUSIONS The eRV and eRI predict biopsy decisions, resectability, and survival better than eloquence grading and may be useful preoperative indices to support surgical decisions

Transverse-Momentum Dependence of the J/psi Nuclear Modification in d+Au Collisions at sqrt(s_NN)=200 GeV

We present measured J/psi production rates in d+Au collisions at sqrt(s_NN) = 200 GeV over a broad range of transverse momentum (p_T=0-14 GeV/c) and rapidity (-2.2<y<2.2). We construct the nuclear-modification factor R_dAu for these kinematics and as a function of collision centrality (related to impact parameter for the R_dAu collision). We find that the modification is largest for collisions with small impact parameters, and observe a suppression (R_dAu<1) for p_T<4 GeV/c at positive rapidities. At negative rapidity we observe a suppression for p_T1) for p_T>2 GeV/c. The observed enhancement at negative rapidity has implications for the observed modification in heavy-ion collisions at high p_T.Comment: 384 authors, 24 pages, 19 figures, 13 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/phenix/WWW/info/data/ppg123_data.htm

The Relationship Between Stimulation Current and Functional Site Localization During Brain Mapping

BackgroundGliomas are often in close proximity to functional regions of the brain; therefore, electrocortical stimulation (ECS) mapping is a common technique utilized during glioma resection to identify functional areas. Stimulation-induced seizure (SIS) remains the most common reason for aborted procedures. Few studies have focused on oncological factors impacting cortical stimulation thresholds.ObjectiveTo examine oncological factors thought to impact stimulation threshold in order to understand whether a linear relationship exists between stimulation current and number of functional cortical sites identified.MethodsWe retrospectively reviewed single-institution prospectively collected brain mapping data of patients with dominant hemisphere gliomas. Comparisons of stimulation threshold were made using t-tests and ANOVAs. Associations between oncologic factors and stimulation threshold were made using multivariate regressions. The association between stimulation current and number of positive sites was made using a Poisson model.ResultsOf the 586 patients included in the study, SIS occurred in 3.92% and the rate of SIS events differed by cortical location (frontal 8.5%, insular 1.6%, parietal 1.3%, and temporal 2.8%; P&nbsp;=&nbsp;.009). Stimulation current was lower when mapping frontal cortex (P&nbsp;=&nbsp;.002). Stimulation current was not associated with tumor plus peritumor edema volume, world health organization) (WHO grade, histology, or isocitrate dehydrogenase (IDH) mutation status but was associated with tumor volume within the frontal lobe (P&nbsp;=&nbsp;.018). Stimulation current was not associated with number of positive sites identified during ECS mapping (P&nbsp;=&nbsp;.118).ConclusionSISs are rare but serious events during ECS mapping. SISs are most common when mapping the frontal lobe. Greater stimulation current is not associated with the identification of more cortical functional sites during glioma surgery

Preoperative Resectability Estimates of Nonenhancing Glioma by Neurosurgeons and a Resection Probability Map

BACKGROUND: Preoperative interpretation of resectability of diffuse nonenhancing glioma is primarily based on individual surgical expertise. OBJECTIVE: To compare the accuracy and precision between observed resections and preoperative estimates of neurosurgeons and a resection probability map (RPM). We hypothesize that the RPM estimates is as good as senior neurosurgeons. METHODS: A total of 234 consecutive patients were included from 2 centers, who had resective surgery with functional mapping between 2006 and 2012 for a supra-tentorial nonenhancing glioma. Extent of resection (EOR) and residual tumor volume (RTV) were segmented and an RPM was constructed in standard brain space. Three junior and three senior neurosurgeons estimated EOR and RTV, blinded for postoperative results. We determined the agreement between the estimates and calculated the diagnostic accuracy of the neurosurgeons and the RPM to predict the observed resections. RESULTS: Preoperative estimates of resection results by junior and senior neurosurgeons were significantly biased towards overestimation of EOR (4.2% and 11.2%) and underestimation of RTV (4.3 and 9.0 mL), whereas estimates of the RPM were unbiased (-2.6% and -.2 mL, respectively). The limits of agreement were wide for neurosurgeons and for the RPM. The RPM was significantly more accurate in identifying patients in whom an EOR >40% was observed than neurosurgeons. CONCLUSION: Neurosurgeons estimate preoperative resectability before surgery of a nonenhancing glioma rather accurate-with a small bias-and imprecise-with wide limits of agreement. An RPM provides unbiased resectability estimates, which can be useful for surgical decision-making, planning, and education