Supratotal Resection Research Articles

Brain Mapping-Aided SupraTotal Resection (SpTR) of Brain Tumors: The Role of Brain Connectivity.

Brain gliomas require a deep knowledge of their effects on brain connectivity. Understanding the complex relationship between tumor and functional brain is the preliminary and fundamental step for the subsequent surgery. The extent of resection (EOR) is an independent variable of surgical effectiveness and it correlates with the overall survival. Until now, great efforts have been made to achieve gross total resection (GTR) as the standard of care of brain tumor patients. However, high and low-grade gliomas have an infiltrative behavior and peritumoral white matter is often infiltrated by tumoral cells. According to these evidences, many efforts have been made to push the boundary of the resection beyond the contrast-enhanced lesion core on T1w MRI, in the so called supratotal resection (SpTR). SpTR is aimed to maximize the extent of resection and thus the overall survival. SpTR of primary brain tumors is a feasible technique and its safety is improved by intraoperative neuromonitoring and advanced neuroimaging. Only transient cognitive impairments have been reported in SpTR patients compared to GTR patients. Moreover, SpTR is related to a longer overall and progression-free survival along with preserving neuro-cognitive functions and quality of life.

High Grade Glioma Surgery - Clinical Aspects and Prognosis.

High grade gliomas (HGG) are a group of tumors with infiltrative nature in general. Surgery is the first step in their treatment. It can be beneficial in two aspects: firstly, in establishing normal intracranial pressure and, secondly, in reducing the tumour volume. The choice of method depends on the location of the lesion, the expected grade of malignancy, and the general condition of the patient. Despite constant development of neuro-oncology and microsurgical techniques, the 5-year survival rate in patients with HGG remains less than 10% and the median survival is still less than 2 years.Aim: At present, there is no final therapeutic "segment" to provide a better outcome than the complex treatment of HGG. Moreover, the treatment's relative efficacy and recurrence of these tumours carry an additional problem. The aim of this study was to estimate the overall survival of patients with HGG operated in our clinic and compare it with literature data.Materials and methods: One hundred twenty-one cranial operations for HGG were reviewed (conducted between 2014 and 2019). Summary characteristics of the various parameters were presented in respect to the radical nature of the operative intervention using Kaplan-Meier analysis and chi square tests. All patients were followed up at regular check-ups. HGGs were 103 or 85.12% of all gliomas operated for the 2014-2019 period. The most common cases were in the 51 to 60 age group. The cases in men were twice as common. The most common localization of the neoplasm is in the temporal region (36.36%) and the rarest was found in the occipital region (3.30%). It was estimated that our operated patients with HGG had 12.23 months over-all survival. Gross total resected patients had a median survival (OS) of 14.53 months, while subtotal resected patients had a median survival (OS) of 10.44 months. It is estimated 7.97 months free tumor survival period (time to relapse - FTS) for our operated patients with HGG. Gross total resected patients had a median FTS of 10.88 months, while subtotal resected patients had median FTS of 5.70 months. We noticed permanent new neurological deficit (NND) in 20 patients (19.45%) operated with GTR, and in 5 patients (4.85%) operated with STR.Conclusions: Median survival - OS, free tumor survival period - FTS and new neurological deficit - NND were statistically significant (p.

Seizure outcome in temporal glioblastoma surgery: lobectomy as a supratotal resection regime outclasses conventional gross-total resection

IntroductionThe postoperative seizure freedom represents an important secondary outcome measure in glioblastoma surgery. Recently, supra-total glioblastoma resection in terms of anterior temporal lobectomy (ATL) has gained growing attention with regard to superior long-term disease control for temporal-located glioblastoma compared to conventional gross-total resections (GTR). However, the impact of ATL on seizure outcome in these patients is unknown. We therefore analyzed ATL and GTR as differing extents of resection in regard of postoperative seizure control in patients with temporal glioblastoma and preoperative symptomatic seizures.MethodsBetween 2012 and 2018, 33 patients with preoperative seizures underwent GTR or ATL for temporal glioblastoma at the authors’ institution. Seizure outcome was assessed postoperatively and 6 months after tumor resection according to the International League Against Epilepsy (ILAE) classification and stratified into favorable (ILAE class 1) versus unfavorable (ILAE class 2–6).ResultsOverall, 23 out of 33 patients (70%) with preoperative seizures achieved favorable seizure outcome following resection of temporal located glioblastoma. For the ATL group, postoperative seizure freedom was present in 13 out of 13 patients (100%). In comparison, respective rates for the GTR group were 10 out of 20 patients (50%) (p = 0.002; OR 27; 95% CI 1.4–515.9).ConclusionsATL in terms of a supra-total resection strategy was associated with superior favorable seizure outcome following temporal glioblastoma resection compared to GTR. Regarding above mentioned survival benefit following ATL compared to GTR, ATL as an aggressive supra-total resection regime might constitute the surgical modality of choice for temporal-located glioblastoma.

Extent of resection and survival outcomes of geriatric patients with glioblastoma: Is there benefit from aggressive surgery?

ObjectiveWe examine the impact of age and extent of resection (EOR) on overall survival (OS) in geriatric patients with Glioblastoma (GBM). MethodsThe SEER 18 Registries was used to identify patients aged 65 and above with GBM from 2000−2016. Patients were categorized into 4 groups based on EOR: Biopsy/Local Excision (B/LE), Subtotal Resection (STR), Gross Total Resection (GTR), and Supratotal Resection (SpTR). Primary endpoint was OS, which was calculated using the Kaplan-Meier method and analyzed by the Log-rank and Wilcoxon-Breslow-Gehan test. Multivariable Cox proportional hazards regression model was utilized to identify factors associated with OS. Likelihood of undergoing SpTR was explored using a multivariable logistic regression model. Results are given as median [IQR] and HR [95 % CI]. ResultsAmong 17,820 geriatric patients with GBM, median age was 73 years [68−78], 44 % were female, 91 % White, and 8% Hispanic. SpTR was performed in 2907 (16 %), GTR was performed in 2451 (14 %) patients, STR in 4879 (28 %), and B/LE in 7396 (42 %). There was a decline in the proportion of patients treated with SpTR with advancing age (65−69 years, 17 % vs 95+ years, 0%; p < 0.0001), and older age corresponded with a decrease in the odds of undergoing SpTR. In survival analysis, GTR (HR 0.61 [0.58−0.65]) and SpTR (HR 0.65 [0.62−0.68]) were associated with improved survival, even in octogenarian patients. ConclusionsThese findings suggest that aggressive surgical resection is associated with improvement in OS in geriatric patients. These results emphasize that age should not influence surgical strategy, as there is a survival benefit from maximal resection in geriatric patients.

Is "En Masse" Tumor Resection a Safe Surgical Strategy for Low-Grade Gliomas? Feasibility Report on 74 Patients Treated Over Four Years.

Gliomas are "confined" tumors arising from a named white fiber tract and displacing adjoining "normal" white fibers. The surgical strategy of "en masse" resection of gliomas based on this concept is evaluated. We evaluate the feasibility of the surgical strategy of "en masse" tumor resection for low-grade gliomas arising from the short arcuate fibers. We retrospectively evaluated our series of 74 patients with low-grade gliomas involving the short arcuate fibers who were operated on between the years January 2016 and June 2019. The tumor resection was done on the premise that gliomas arise from and grew along a specific white fiber tract and the expanding tumor displaced but did not transgress the border formed by adjoining tracts. Although modified as per the situation, an en masse tumor resection strategy was the basis of surgical resection. Intraoperative motor cortical and subcortical mapping was performed in 14 cases. Awake surgery was performed on 11 patients. There were 46 males and 28 females. Total/supratotal tumor resection was achieved in 62 (83.8%) patients. Forty-seven patients had an essentially en masse tumor resection. Seventy-one patients improved in their preoperative complaints. The follow-up ranged from 11 to 56 months. Sixty-two patients who underwent a total or supratotal resection were not given any adjuvant treatment. Twelve patients with subtotal resection were subjected to adjuvant radiotherapy with or without additional chemotherapy. En masse tumor resection of low-grade gliomas is possible and "safe" based on understanding that gliomas are "confined" tumors and have a well-defined plane of surgical dissection.

Endoscope-assisted fluorescence-guided resection allowing supratotal removal in glioblastoma surgery.

Several studies have proven the benefits of a wide extent of resection (EOR) of contrast-enhancing tumor in terms of progression-free survival (PFS) and overall survival (OS) in patients with glioblastoma (GBM). Thus, gross-total resection (GTR) is the main surgical goal in noneloquently located GBMs. Complete tumor removal can be almost doubled by microscopic fluorescence guidance. Recently, a study has shown that an endoscope with a light source capable of inducing fluorescence allows visualization of remnant fluorescent tumor tissue even after complete microscopic fluorescence-guided (FG) resection, thereby increasing the rate of GTR. Since tumor infiltration spreads beyond the borders of contrast enhancement on MRI, the aim of this study was to determine via volumetric analyses of the EOR whether endoscope-assisted FG resection enables supratotal resection beyond the borders of contrast enhancement. The authors conducted a retrospective single-center analysis of a consecutive series of patients with primary GBM presumed to be noneloquently located and routinely operated on at their institution between January 2015 and February 2018 using a combined microscopic and endoscopic FG resection. A 20-mg/kg dose of 5-aminolevulinic acid (5-ALA) was administered 4 hours before surgery. After complete microscopic FG resection, the resection cavity was scanned using the endoscope. Detected residual fluorescent tissue was resected and embedded separately for histopathological examination. Nonenhanced and contrast-enhanced 3D T1-weighted MR images acquired before and within 48 hours after tumor resection were analyzed using 3D Slicer. Bias field-corrected data were used to segment brain parenchyma, contrast-enhancing tumor, and the resection cavity for volume definition. The difference between the pre- and postoperative brain parenchyma volume was considered to be equivalent to the resected nonenhancing but fluorescent tumor tissue. The volume of resected tumor tissue was calculated from the sum of resected contrast-enhancing tumor tissue and resected nonenhancing tumor tissue. Twelve patients with GBM were operated on using endoscopic after complete microscopic FG resection. In all cases, residual fluorescent tissue not visualized with the microscope was detected. Histopathological examination confirmed residual tumor tissue in all specimens. The mean preoperative volume of brain parenchyma without contrast-enhancing tumor was 1213.2 cm3. The mean postoperative volume of brain parenchyma without the resection cavity was 1151.2 cm3, accounting for a mean volume of nonenhancing but fluorescent tumor tissue of 62.0 cm3. The mean relative rate of the overall resected volume compared to the contrast-enhancing tumor volume was 244.7% (p < 0.001). Combined microscopic and endoscopic FG resection of GBM significantly increases the EOR and allows the surgeon to achieve a supratotal resection beyond the borders of contrast enhancement in noneloquently located GBM.

Brain mapping-aided SupraTotal Resection (SpTR) of brain tumors: the role of brain connectivity

Brain mapping-aided SupraTotal Resection (SpTR) of brain tumors: the role of brain connectivity

Hyperspectral Imaging for Glioblastoma Surgery: Improving Tumor Identification Using a Deep Spectral-Spatial Approach.

The primary treatment for malignant brain tumors is surgical resection. While gross total resection improves the prognosis, a supratotal resection may result in neurological deficits. On the other hand, accurate intraoperative identification of the tumor boundaries may be very difficult, resulting in subtotal resections. Histological examination of biopsies can be used repeatedly to help achieve gross total resection but this is not practically feasible due to the turn-around time of the tissue analysis. Therefore, intraoperative techniques to recognize tissue types are investigated to expedite the clinical workflow for tumor resection and improve outcome by aiding in the identification and removal of the malignant lesion. Hyperspectral imaging (HSI) is an optical imaging technique with the power of extracting additional information from the imaged tissue. Because HSI images cannot be visually assessed by human observers, we instead exploit artificial intelligence techniques and leverage a Convolutional Neural Network (CNN) to investigate the potential of HSI in twelve in vivo specimens. The proposed framework consists of a 3D–2D hybrid CNN-based approach to create a joint extraction of spectral and spatial information from hyperspectral images. A comparison study was conducted exploiting a 2D CNN, a 1D DNN and two conventional classification methods (SVM, and the SVM classifier combined with the 3D–2D hybrid CNN) to validate the proposed network. An overall accuracy of 80% was found when tumor, healthy tissue and blood vessels were classified, clearly outperforming the state-of-the-art approaches. These results can serve as a basis for brain tumor classification using HSI, and may open future avenues for image-guided neurosurgical applications.

STMO-11 Supratotal resection of Glioblastoma with Methionine PET

Objective: To assess the resection of both of contrast-enhanced (CE) and methionine-uptake (MU) and the oncological outcome in newly diagnosed glioblastoma. Methods: This retrospective study included a glioblastoma cohort from Chiba University who met the two criteria, i) total resection of CE tumor, ii) preoperative evaluation with methionine positron emission tomography (Met-PET). Data regarding the pattern of recurrence and overall survival were collected. Results: Among 247 cases with glioblastoma, total resection of CE was achieved in 112. Preoperative Met-PET was performed in 30 out of 112. The median age at operation, a period of follow-up, and the preoperative tumor volume in 30 patients were 56 year-old, 17.9 months, and 18.8 cc respectively. The promoter region of the O6-methylguanine-DNA methyltransferase was methylated in 37%. Radiological comparison revealed that Met uptake was detected beyond the CE area in 13 out of 30, and the Met uptake was also resected with awake mapping technique in 7 patients (supratotal resection group; STR). The median progression-free survival (PFS) in STR was 23 months, and all the patterns of recurrence were distant recurrence. In contrast, the PFS in total resection group (TRG) was 9 months (p=0.09, Wilcoxon). Furthermore, 14 out of 17 recurrence were local in TRG subgroup. While the median OS in TRG was 18 months, it has not reached in STR (p=0.04, Wilcoxon). Conclusions: The resection of both of CE and MU was associated with better PFS and OS. This finding must be validated in a larger cohort with a multicenter study.

NIMG-66. AI-BASED PROGNOSTIC IMAGING BIOMARKERS FOR PRECISION NEUROONCOLOGY AND THE RESPOND CONSORTIUM

Abstract AI-based methods have shown great promise in a variety of biomedical research fields, including neurooncologic imaging. For example, machine learning methods have offered informative predictions of overall survival (OS) and progression-free survival (PFS), differentiation between pseudoprogression (PsP) and progressive disease (PD), and estimation of mutational status from imaging data. Despite their promise, AI, and especially the emerging deep learning (DL) methods, are challenged by several factors, including imaging heterogeneity across scanners and lack of sufficiently large and diverse training datasets, which limits their reproducibility and general acceptance. These challenges prompted the development of the ReSPOND (Radiomics Signatures for PrecisiON Diagnostics) consortium on glioblastoma, a growing effort to bring together a community of researchers sharing imaging, demographic, clinical and (currently) limited molecular data in order to address the following aims: 1) pool and harmonize data across diverse hospitals and patient populations worldwide; 2) derive robust and generalizable AI models for prediction of (initially) OS, PFS, PsP vs. PD, and recurrence; 3) test these predictive models across multiple sites. In its first phase, ReSPOND aims to pool together approximately 3,000MRI scans (from 10institutions plus TCIA), along with demographics, KPS, and (for a subset) MGMT/IDH1 status. We present initial results testing the generalization of a previously trained model of OS on 505Penn datasets to 2independent cohorts from Case Western Reserve University and University Hospitals (N=44), and Penn (N=67). The results indicate good generalization, with correlation coefficients between OS/predicted-OS between 0.25 to 0.5, depending on variable availability, which is comparable to cross-validated accuracy previously obtained from the training set itself (N=505). Additional preliminary studies evaluating prediction of future recurrence from baseline pre-operative scans in de novo patients (Penn model applied to CWR) indicated potential for guiding targeted dose escalation and supra-total resection (excellent predictions in 6/12 patients, modest in 1/12, and poor in 5/12).

SURG-22. PATTERN OF RECURRENCE ALONG EXTENT OF RESECTION IN PATIENTS WITH GLIOBLASTOMA, IDH-WILDTYPE: A RETROSPECTIVE STUDY

Abstract OBJECTIVE The concept for maximal resection of glioblastoma(GBM) is changing to resect not only contrast-enhanced (CE) tumor but non-contrast-enhanced (NCE) tumor. Although maximal resection is associated with longer survival, the pattern of recurrence in glioblastoma, isocitrate dehydrogenase (IDH)-wildtype patient is poorly understood. METHODS This retrospective, single-center study included 358 eligible patients through November 1, 2005 to December 31, 2018. Those patients were grouped along extent of resection (subtotal resection (STR, n=123), gross-total resection (GTR, n=194), and supratotal resection (SupTR, n=41)). The pattern of recurrence was classified based on the range of radiation treatment, into infield gross target volume (GTV), infield clinical target volume (CTV), marginal, outfield and CSF seeding. RESULTS Tumor recurrence was observed for each group as follows: STR group, 80.5%, GTR group, 75.3%, and SupTR group, 63.4%. Statistical differences in pattern of recurrence among each group were observed in infield GTV (STR group:75.8%, GTR group: 71.9%, and SupTR group: 42.3%, p=0.003) and Outfield (STR group:11.0%, GTR group: 21.2%, SupTR group: 34.6%, p=0.012) recurrence. The survival for SupTR group was significantly longer than that for the STR and GTR in terms of both overall survival (OS) and progression free survival (PFS) (OS, STR: 15.7m, GTR: 21.6m, SupTR: 44.7m, PFS, STR: 10.4m, GTR: 14.3m, SupTR: 35.5m) CONCLUSIONS As the extent of resection increased, local recurrence decreased and distant recurrence increased. During treatment of glioblastoma, expectation

SURG-39. 5-AMINOLEVULINIC ACID FLUORESCENCE (5-ALA) GUIDED RESECTION OF GLIOBLASTOMA, LESSON LEARNED FROM 26 CASES

Abstract INTRODUCTION 5-ALA is known as useful tool for high grade glioma resection and the accumulation extent of 5-ALA is known as far beyond gadolinium enhancement. Extent of resection is key factor for favorable outcome and long-term survival for high grade glioma patients and 5-ALA might increase extent of resection. We present our experience of 5-ALA guided glioma surgeries. MATERIALS AND METHODS Total 26 patients were performed 5-ALA guided surgery. They ingested 20mg/kg, four hours before craniotomy. We tried to perform supra-total resection rather than gross total resection according to the tumor consistency and if the tumor located relatively non-eloquent area, we tried to perform lobectomy rather than lesionectomy. After tumor resection, we inspect the tumor bed under 5-ALA fluorescence, and we confirmed the complete loss of fluorescence on the tumor resected bed. We check the MRI within 48 hour after operation and assess the extent of resection. RESULTS Among the 26 patients, 22 patients were confirmed glioblastoma and 3 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. We confirmed all enhancing lesion was completely removed, however, 4 patients show residual non-enhancing lesion in post-operative MRI. Two patients suffered temporary hemiparesis and 2 patients show permanent visual field defect. CONCLUSION 5-ALA is useful tool for glioma surgery. Resection extent could be increased, however, non-enhancing lesion in the high grade gliomas, might be missed under 5-ALA guidance.

SURG-14. AWAKE CRANIOTOMY VS CRANIOTOMY UNDER GENERAL ANESTHESIA FOR GLIOBLASTOMAS: EVALUATING THE IMPACT ON OVERALL SURVIVAL AND RISK OF RECURRENCE

Abstract Maximum safe resection for eloquent glioblastomas (GBMs) is the maximum tumor resection achievable without causing neurological deficits. Although challenging, it must be considered the therapeutic target for GBMs. Indeed, the extension of resection positively correlates with the overall survival and recurrences risk. Awake surgery (AS) has become paramount for achieving maximum safe resection for tumors in eloquent areas. However, there is not a unanimous consensus on the extent of resection of eloquent GBMs, especially for what concerns the so-called supratotal resection (i.e.: resection over the contrast-enhancing limits of the lesion). Recently, several studies focused their attention on the residual tumor volume as estimated from T1-contrast enhanced sequences, but few analyzed the outcomes of patients with a more extended resection. Some authors speculated that increased surgical aggressiveness, thus removing peritumoral edematous area, correlates with improved overall survival and tumor control, without increasing adverse events rates. This study aimed to assess, through quantitative volumetric analysis, the outcomes of a prospectively collected cohort of patients with primary GBM located in eloquent areas. We furtherly subdivided our population into two treatment groups: awake surgery (AS) and general anesthesia (GA) craniotomies. We analyzed the overall outcomes, especially for what concerns MRI T2-Flair signal extent of resection, related to patients’ survival and recurrences formation. Eventually, we stratified our analysis by type of treatment (awake surgery vs. general anesthesia) to rule out any significant differences in survival and postoperative GBMs behaviors. Our data confirmed extensive that T2-Flair resection (EOR≥30%) and AS could improve overall survival and reduce risk of recurrence without, at the same time, causing an increase of surgical and medical complications

Association of supratotal resection with progression-free survival, malignant transformation, and overall survival in lower-grade gliomas.

Supratotal resection is advocated in lower-grade gliomas (LGGs) based on theoretical advantages but with limited verification of functional risk and data on oncological outcomes. We assessed the association of supratotal resection in molecularly defined LGGs with oncological outcomes. Included were 460 presumptive LGGs; 404 resected; 347 were LGGs, 319 isocitrate dehydrogenase (IDH)-mutated, 28 wildtype. All patients had clinical, imaging, and molecular data. Resection aimed at supratotal resection without any patient or tumor a priori selection. The association of extent of resection (EOR), categorized on volumetric fluid attenuated inversion recovery images as residual tumor volume, along with postsurgical management with progression-free survival (PFS), malignant (M)PFS, and overall survival (OS) assessed by univariate, multivariate, and propensity score analysis. The study mainly focused on IDH-mutated LGGs, the "typical LGGs." Median follow-up was 6.8 years (interquartile range, 5-8). Out of 319 IDH-mutated LGGs, 190 (59.6%) progressed, median PFS: 4.7 years (95% CI: 4-5.3). Total and supratotal resection obtained in 39% and 35% of patients with IDH1-mutated tumors. In IDH-mutated tumors, most patients in the partial/subtotal group progressed, 82.4% in total, only 6 (5.4%) in supratotal. Median PFS was 29 months (95% CI: 25-36) in subtotal, 46 months (95% CI: 38-48) in total, while at 92 months, PFS in supratotal was 94.0%. There was no association with molecular subtypes and grade. At random forest analysis, PFS strongly associated with EOR, radiotherapy, and previous treatment. In the propensity score analysis, EOR associated with PFS (hazard ratio, 0.03; 95% CI: 0.01-0.13). MPFS occurred in 32.1% of subtotal total groups; 1 event in supratotal. EOR, grade III, previous treatment correlated to MPFS. At random forest analysis, OS associated with EOR as well. Supratotal resection strongly associated with PFS, MPFS, and OS in LGGs, regardless of molecular subtypes and grade, right from the beginning of clinical presentation.

Safety metric profiling in surgery for temporal glioblastoma: lobectomy as a supra-total resection regime preserves perioperative standard quality rates

IntroductionSupra-total resection in terms of anterior temporal lobectomy (ATL) has gained growing attention with regard to superior long-term disease control for temporal-located glioblastoma. However, aggressive onco-surgical approaches—geared beyond conventional gross total resections (GTR)—may be associated with peri- and postoperative unfavorable events which significantly worsen initial favorable postoperative outcome. In the current study we analyzed our institutional database with regard to patient safety indicators (PSIs), hospital-acquired conditions (HACs) and specific cranial surgery-related complications (CSC) as high standard quality metric profiles in patients that had undergone surgery for temporal glioblastoma.MethodsBetween 2012 and 2018, 61 patients with temporal glioblastoma underwent GTR or temporal lobectomy at the authors’ institution. Both groups of differing resection modalities were analyzed with regard to the incidence of PSIs, HACs and CSCs.ResultsOverall, we found 6 PSI and 2 HAC events. Postoperative hemorrhage (3 out of 61 patients; 5%) and catheter-associated urinary tract infection (2 out 61 patients; 3%) were identified as the most frequent PSIs and HACs. PSIs were present in 1 out of 41 patients (5%) for the temporal GTR and 2 out of 20 patients for the lobectomy group (p = 1.0). Respective rates for PSIs were 5 of 41 (12%) and 1 of 20 (5%) (p = 0.7). Further, CSCs did not yield significant differences between these two resection modalities (p = 1.0).ConclusionWith regard to ATL and GTR as differing onco-surgical approaches these data suggest ATL in terms of an aggressive supra-total resection strategy to preserve perioperative standard safety metric profiles.

Effects of supra-total resection in neurocognitive and oncological outcome of high-grade gliomas comparing asleep and awake surgery.

Awake surgery is an established technique for resection of low-grade gliomas, while its possible benefit for resection of high-grade gliomas (HGGs) needs further confirmations. This retrospective study aims to compare overall survival, extent of resection(EOR) and cognitive outcome in two groups of HGGs patients submitted to asleep or awake surgery. Thirty-three patients submitted to Gross Total Resection of contrast-enhancing area of HGGs were divided in two homogeneous groups: awake (AWg; N = 16) and asleep surgery (ASg; N = 17). All patients underwent toan extensive neuropsychological assessment before surgery (time_1), 1-week (time_2) and 4-months (time_3) after surgery. We performed analyses to assess differences in cognitive performances between groups, cognitive outcomes in each group and EOR. A comparison of overallsurvival(OS) between the twogroups was conducted. Statisticalanalyses showed no differences between groups at time_2 and time_3 in each cognitive domain, excludingselective attentionthat resulted higher in the AWg before surgery. Regarding cognitive outcomes, we found a reversible worsening of memory and constructional praxis, and a significant recovery at time_3, similar for both groups. Assessment of time_3 in respect to time_1 never showed differences (all ps > .074). Moreover we found a significant lower level of tumor infiltration after surgery for AWg (p < .05), with an influence on OS (p < .05). Indeed, patients of AWg showed a significant longer OS in comparison to those in theASg (p < .01). This result was confirmed even considering only wildtype Glioblastoma (p < .05). These results indicate that awake surgery, and in general asupra-total resection of enhancing area, can improve OS in HGGs patients, preserving neuro-cognitive profile and quality of life.

Gross Total Resection of a Grade IV Astrocytoma Adjacent to the Precentral Gyrus With Nonawake Motor Mapping and Motor-Evoked Potential Monitoring: 3-Dimensional Operative Video.

Surgical treatment of the gliomas located in or adjacent to the eloquent areas poses significant challenge to neurosurgeons. The main goal of the surgery is to achieve maximal safe resection while preserving the neurological function. This might be possible with utilizing pre- and intraoperative adjuncts such as functional magnetic resonance imaging (MRI), image guidance, mapping of the function of interest, intraoperative MRI, and neurophysiological monitoring. In this video, we demonstrate the utilization of nonawake mapping and motor-evoked potential (MEP) monitoring for the resection of a right-sided posterior superior frontal gyrus grade IV astrocytoma adjacent to the primary motor cortex. The patient is a 69-yr-old woman presented with multiple episodes of simple partial seizures involving her left leg and spreading to the left arm. MRI and functional MRI examinations showed a heterogeneously enhancing mass with peritumoral edema adjacent to the primary motor cortex. Because the patient did not want to undergo an awake craniotomy, a decision was made to perform the resection of the tumor with nonawake motor mapping and continuous MEP monitoring. Nonawake motor mapping and MEP monitoring enabled us to perform gross total resection. Because it has been shown that supratotal resection may provide improved survival outcome,1,2 we extended the white matter resection beyond the contrast enhancing area in noneloquent parts of the tumor. Surgical steps in dealing with vascular anatomy as well as utilizing intraoperative adjuncts such as motor mapping and MEP monitoring to enhance the extent of resection while preserving the function are demonstrated in this 3-dimensional surgical video. The patient consented to publication of her operative video.

SURG-16. SUPRATOTAL VERSUS GROSS TOTAL RESECTION OF GLIOBLASTOMA: A SYSTEMATIC REVIEW

Abstract INTRODUCTION Due to the infiltrative nature of glioblastoma(GBM) outside of the contrast enhancing region in the peritumoral zone, there is increasing movement to perform supratotal resections (SpTR) by extending the edge of resection beyond the contrast enhancing portion of the tumor. However, there is currently no consensus on the potential survival benefit of SpTR in GBM as compared to gross total resection (GTR). METHODS Therefore, we performed a systematic review using PRISMA guidelines and performed a comprehensive literature search on Pubmed, EMBASE, The Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov, from inception to August 16, 2018, to identify articles comparing overall survival (OS) after SpTR versus GTR. Furthermore, we assessed study quality using the Oxford Centre for Evidence-Based Medicine guidelines. RESULTS We identified 8902 unique citations, of which 11 articles and 2 abstracts met study inclusion criteria. 925 patients underwent SpTR out of a total of 2137 patients. 9 of the 13 studies demonstrated improved survival with SpTR compared to GTR (median improvement in OS of 10.5 months), with no significant difference in post-operative complication rate. Conversely, one abstract found worsened outcomes with SpTR compared to GTR (median decrease in OS of 4 months). However, overall study quality was poor, with 12 of the 13 studies of level IV evidence and one study of level IIIb evidence. We were unable to perform a meta-analysis due to significant clinical and methodological heterogeneity amongst the studies (e.g. differences in adjuvant therapy and lack of standardization of definition of supratotal resection). CONCLUSIONS Our systematic review indicates that SpTR may be associated with improved OS compared to GTR for GBM. However, this is limited by poor study quality and significant clinical and methodological heterogeneity amongst the studies. There is need for prospective clinical trials to further establish standardized guidelines for SpTR in GBM.

SURG-18. 5-AMINOLEVULINIC ACID FLUORESCENCE (5-ALA) GUIDED RESECTION OF GLIOBLASTOMA, LESSON LEARNED FROM 19 CASES

Abstract BACKGROUND 5-ALA is known as useful tool for high grade glioma resection and the accumulation extent of 5-ALA is known as far beyond gadolinium enhancement. Extent of resection is key factor for favorable outcome and long-term survival for high grade glioma patients and 5-ALA might increase extent of resection. We present our experience of 5-ALA guided glioma surgeries METHODS Total 19 patients were performed 5-ALA guided surgery. They ingested 20mg/kg, four hours before craniotomy. We tried to perform supra-total resection rather than gross total resection according to the tumor consistency and if the tumor located relatively non-eloquent area, we tried to perform lobectomy rather than lesionectomy. After tumor resection, we inspect the tumor bed under 5-ALA fluorescence, and we confirmed the complete loss of fluorescence on the tumor resected bed. We check the MRI within 48 hour after operation and assess the extent of resection RESULTS Among the 19 patients, 15 patients were confirmed glioblastoma and 3 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. We confirmed all enhancing lesion was completely removed, however, 2 patients show residual non-enhancing lesion in post-operative MRI. Two patients suffered temporary hemiparesis and 2 patients show permanent visual field defect. CONCLUSION 5-ALA is useful tool for glioma surgery. Resection extent could be increased, however, non-enhancing lesion in the high grade gliomas, might be missed under 5-ALA guidance.

P14.44 Survival benefit of lobectomy over gross-total resection without lobectomy in cases of glioblastoma in the noneloquent area: a retrospective study

Abstract BACKGROUND Following resection of glioblastoma (GBM), microscopic remnants of the GBM tumor remaining in nearby tissue cause tumor recurrence more often than for other tumors, even after gross-total resection (GTR). Although surgical oncologists traditionally resect some of the surrounding normal tissue, whether further removal of nearby tissue may improve survival in GBM patients is unknown. In this single-center retrospective study, the authors assessed whether lobectomy confers a survival benefit over GTR without lobectomy when treating GBMs in the noneloquent area. MATERIAL AND METHODS The authors selected 40 patients who had undergone GTR of a histopathologically diagnosed isocitrate dehydrogenase (IDH)-wild type GBM in the right frontal or temporal lobe and divided the patients into 2 groups according to whether GTR of the tumor involved lobectomy, defined as a supratotal resection (SupTR group, n = 20) or did not (GTR group, n = 20). Progression-free survival (PFS), overall survival (OS), and Karnofsky Performance Status (KPS) scores were compared between groups (p ≤ 0.05 for statistically significant differences). RESULTS The median postoperative PFS times for each group were as follows: GTR group, 11.5 months (95% CI 8.8–14.2) and SupTR group, 30.7 months (95% CI 4.3–57.1; p = 0.007). The median postoperative OS times for each group were as follows: GTR group, 18.7 months (95% CI 14.3–23.1) and SupTR group, 44.1 months (95% CI 25.1–63.1; p = 0.040). The mean postoperative KPS scores (GTR, 76.5; SupTR, 77.5; p = 0.904) were not significantly different. In multivariate analysis, survival for the SupTR group was significantly longer than that for the GTR group in terms of both PFS (HR 0.230; 95% CI 0.090–0.583; p = 0.002) and OS (HR 0.247; 95% CI 0.086–0.704; p = 0.009). CONCLUSION In cases of completely resectable, noneloquent area GBMs, SupTR provides superior PFS and OS without negatively impacting patient performance.