Survival benefit of lobectomy for glioblastoma: moving towards radical supramaximal resection

Metabolic signatures derived from whole-brain MR-spectroscopy identify early tumor progression in high-grade gliomas using machine learning

PURPOSE

Recurrence for high-grade gliomas is inevitable despite maximal safe resection and adjuvant chemoradiation, and current imaging techniques fall short in predicting future progression. However, we introduce a novel whole-brain magnetic resonance spectroscopy (WB-MRS) protocol that delves into the intricacies of tumor microenvironments, offering a comprehensive understanding of glioma progression to inform expectant surgical and adjuvant intervention.

METHODS

We investigated five locoregional tumor metabolites in a post-treatment population and applied machine learning (ML) techniques to analyze key relationships within seven regions of interest: contralateral normal-appearing white matter (NAWM), fluid-attenuated inversion recovery (FLAIR), contrast-enhancing tumor at time of WB-MRS (Tumor), areas of future recurrence (AFR), whole-brain healthy (WBH), non-progressive FLAIR (NPF), and progressive FLAIR (PF). Five supervised ML classification models and a neural network were developed, optimized, trained, tested, and validated. Lastly, a web application was developed to host our novel calculator, the Miami Glioma Prediction Map (MGPM), for open-source interaction.

RESULTS

Sixteen patients with histopathological confirmation of high-grade glioma prior to WB-MRS were included in this study, totaling 118,922 whole-brain voxels. ML models successfully differentiated normal-appearing white matter from tumor and future progression. Notably, the highest performing ML model predicted glioma progression within fluid-attenuated inversion recovery (FLAIR) signal in the post-treatment setting (mean AUC = 0.86), with Cho/Cr as the most important feature.

CONCLUSIONS

This study marks a significant milestone as the first of its kind to unveil radiographic occult glioma progression in post-treatment gliomas within 8 months of discovery. These findings underscore the utility of ML-based WB-MRS growth predictions, presenting a promising avenue for the guidance of early treatment decision-making. This research represents a crucial advancement in predicting the timing and location of glioblastoma recurrence, which can inform treatment decisions to improve patient outcomes.

Principles in the Management of Glioblastoma

Glioblastoma, the most aggressive and common malignant primary brain tumour, is characterized by infiltrative growth, abundant vascularization, and aggressive clinical evolution. Patients with glioblastoma often face poor prognoses, with a median survival of approximately 15 months. Technological progress and the subsequent improvement in understanding the pathophysiology of these tumours have not translated into significant achievements in therapies or survival outcomes for patients. Progress in molecular profiling has yielded new omics data for a more refined classification of glioblastoma. Several typical genetic and epigenetic alterations in glioblastoma include mutations in genes regulating receptor tyrosine kinase (RTK)/rat sarcoma (RAS)/phosphoinositide 3-kinase (PI3K), p53, and retinoblastoma protein (RB) signalling, as well as mutation of isocitrate dehydrogenase (IDH), methylation of O6-methylguanine-DNA methyltransferase (MGMT), amplification of epidermal growth factor receptor vIII, and codeletion of 1p/19q. Certain microRNAs, such as miR-10b and miR-21, have also been identified as prognostic biomarkers. Effective treatment options for glioblastoma are limited. Surgery, radiotherapy, and alkylating agent chemotherapy remain the primary pillars of treatment. Only promoter methylation of the gene MGMT predicts the benefit from alkylating chemotherapy with temozolomide and it guides the choice of first-line treatment in elderly patients. Several targeted strategies based on tumour-intrinsic dominant signalling pathways and antigenic tumour profiles are under investigation in clinical trials. This review explores the potential genetic and epigenetic biomarkers that could be deployed as analytical tools in the diagnosis and prognostication of glioblastoma. Recent clinical advancements in treating glioblastoma are also discussed, along with the potential of liquid biopsies to advance personalized medicine in the field of glioblastoma, highlighting the challenges and promises for the future.

Regulation of cancer stem cells and immunotherapy of glioblastoma (Review)

Glioblastoma (GB) is one of the most adverse diagnoses in oncology. Complex current treatment results in a median survival of 15 months. Resistance to treatment is associated with the presence of cancer stem cells (CSCs). The present review aimed to analyze the mechanisms of CSC plasticity, showing the particular role of β-catenin in regulating vital functions of CSCs, and to describe the molecular mechanisms of Wnt-independent increase of β-catenin levels, which is influenced by the local microenvironment of CSCs. The present review also analyzed the reasons for the low effectiveness of using medication in the regulation of CSCs, and proposed the development of immunotherapy scenarios with tumor cell vaccines, containing heterogenous cancer cells able of producing a multidirectional antineoplastic immune response. Additionally, the possibility of managing lymphopenia by transplanting hematopoietic stem cells from a healthy sibling and using clofazimine or other repurposed drugs that reduce β-catenin concentration in CSCs was discussed in the present study.

Nitric oxide synthase inhibitors as potential therapeutic agents for gliomas: A systematic review

INTRODUCTION

Gliomas represent the most prevalent form of brain tumors, among which glioblastomas are the most malignant subtype. Despite advances in comprehending their biology and treatment strategies, median survival remains disappointingly low. Inflammatory processes involving nitric oxide (NO), critically contribute to glioma formation. The inducible isoform of NO synthase (iNOS) is highly overexpressed in gliomas and has been linked to resistance against temozolomide (TMZ) treatment, neoplastic transformation, and modulation of immune response. While both in vitro and in vivo studies showed the potential of iNOS inhibitors as effective treatments for gliomas, no clinical trials on gliomas have been published. This review aims to summarize the available evidence regarding iNOS as a target for glioma treatment, focusing on clinically relevant data.

METHODS

Following PRISMA guidelines, we conducted a systematic review by searching PubMed/Medline, and Embase databases in May 2023. We included studies that investigated the impact of NOS inhibitors on glioma cells using L-NMMA, CM544, PBN, 1400W or l-NAME either alone or combined with TMZ. We extracted data on the NOS inhibitor used, subtype, study setting, animal model or cell lines employed, obtained results, and safety profile. Our inclusion criteria encompassed original articles in English or Spanish, studies with an untreated control group, and a primary outcome focused on the biological effects on glioma cells.

RESULTS

Out of 871 articles screened from the aforementioned databases, 37 reports were assessed for eligibility. After excluding studies that did not utilize glioma cells or address the designated outcome, 11 original articles satisfied the inclusion and exclusion criteria. Although no NOS inhibitor has been tested in a published clinical trial, three inhibitors have been evaluated using in vivo models of intracranial gliomas. l-NAME, 1400W, and CM544 were tested in vitro. Co-administration of l-NAME, or CM544 with TMZ showed superior results in vitro compared to individual agent testing.

CONCLUSION

Glioblastomas remain a challenging therapeutic target. iNOS inhibitors exhibit substantial potential as treatment options for oncologic lesions, and they have demonstrated a safe toxicity profile in humans for other pathological conditions. Research endeavors should be focused on investigating their potential effects on brain tumors.

Supramaximal resection based on en-bloc technique reduces tumor burden and prolongs survival in primary supratentorial lobar glioblastoma

PURPOSE

Resection beyond the contrast-enhanced zone contributed to reduce tumor burden and prolong survival in glioblastomas. The optimal extent of resection (EOR) and how to achieve it are worthy of continuous investigation for obtaining a satisfactory balance between maximal resection and the preservation of neurological function.

METHODS

A total of 340 adult supratentorial lobar glioblastomas (included astrocytoma, WHO 4, IDH mutation and glioblastoma) were retrospectively evaluated. The clinical data, EOR, technique of resection, postoperative complications, overall survival (OS) and progression-free survival (PFS) were assessed by univariate, multivariate and propensity score matched analysis. Histological staining was performed to comprehend the effect of the membranous structures and the cell distribution in tumoral and peritumoral regions.

RESULTS

Supramaximal resection (SMR) was confirmed as resection with 100% EORCE and > 50% EORnCE in glioblastomas by Cox proportional hazards model. Histological results showed SMR reduced the cell density of surgical edge compared to total resection. En-bloc technique based on membranous structures, which had blocking effect on tumoral invasion, contributed to achieve SMR. Moreover, applying en-bloc technique and achieving SMR did not additionally deteriorate neurological function and had similarly effects on the improvement of neurological function. Multivariate analysis confirmed that IDH1 status, technique of resection and EOR were independently correlated with PFS, and > 64 years old, IDH1 status, technique of resection, EOR and preoperative NIHSS were independently correlated with OS.

CONCLUSIONS

Applying en-bloc technique and achieving SMR, which could reduce tumor burden and did not increase additional complications, both had remarkedly positive effects on clinical outcomes in patients with primary supratentorial lobar glioblastomas.

Lobectomy versus gross total resection for glioblastoma multiforme: A systematic review and individual-participant data meta-analysis

Overall survival (OS)for glioblastoma multiforme (GBM) has a known association with the extent of tumor resection with gross total resection (GTR) typically considered as the upper limit. In certain regions such as the anterior temporal lobe, more extensive resection by means of a lobectomy may be feasible. In our systematic review and meta-analysis, we aimed to compare the outcomes of lobectomy and GTR for GBM. PubMed and Embase were queriedfor studies that compared the outcomes after lobectomy or GTR for GBM. The primary outcomes were OS, progression-free survival (PFS), and Karnofksy Performance Status (KPS) score at the latest follow-up. The secondary outcomes were seizure control at the latest follow-up and complication rates. Meta-analysis for OS and PFS was performed using individual-participant data reconstructed from published Kaplan-Meier curves. Random-effect meta-analysis was performed for KPS. The secondary outcomes were pooled using descriptive statistics. Of the 795 records screened, 6 were included in our study. Meta-analysis revealed that anterior temporal, frontal, or occipital lobectomy was associated with significantly better OS (p < 0.001) and PFS (p < 0.001) than GTR, but not KPS (MD = 6.37; 95% CI=(-13.80, 26.54); p = 0.536). Anterior temporal lobectomy was associated with significantly better seizure control rates than GTR for temporal GBM (OR = 27; 95% CI=(1.4, 515.9); p = 0.002). There was no statistically significant difference in complication rates between anterior temporal, frontal, or occipital lobectomy and GTR. In conclusion, lobectomy was associated with significantly better OS, PFS, and seizure control than GTR for GBM.

Supramaximal Resection Can Prolong the Survival of Patients with Cortical Glioblastoma: A Volumetric Study

We aimed to retrospectively determine the resection rate of fluid-attenuated inversion recovery (FLAIR) lesions to evaluate the clinical effects of supramaximal resection (SMR) on the survival of patients with glioblastoma (GBM). Thirty-three adults with newly diagnosed GBM who underwent gross total tumor resection were enrolled. The tumors were classified into cortical and deep-seated groups according to their contact with the cortical gray matter. Pre- and postoperative FLAIR and gadolinium-enhanced T1-weighted imaging tumor volumes were measured using a three-dimensional imaging volume analyzer, and the resection rate was calculated. To evaluate the association between SMR rate and outcome, we subdivided patients whose tumors were totally resected into the SMR and non-SMR groups by moving the threshold value of SMR in 10% increments from 0% and compared their overall survival (OS) change. An improvement in OS was observed when the threshold value of SMR was 30% or more. In the cortical group (n = 23), SMR (n = 8) tended to prolong OS compared with gross total resection (GTR) (n = 15), with the median OS of 69.6 and 22.1 months, respectively (p = 0.0945). Contrastingly, in the deep-seated group (n = 10), SMR (n = 4) significantly shortened OS compared with GTR (n = 6), with median OS of 10.2 and 27.9 months, respectively (p = 0.0221). SMR could help prolong OS in patients with cortical GBM when 30% or more volume reduction is achieved in FLAIR lesions, although the impact of SMR for deep-seated GBM must be validated in larger cohorts.

Tumor sound, auditory cues, and tissue pathology in glioma surgery: a proof-of-concept study

OBJECTIVE

Visual, tactile, and auditory cues are used during surgery to differentiate tissue type. Auditory cues in glioma surgery have not been studied previously. The objectives of this study were 1) to evaluate the feasibility of recording sound generated by the suction device during glioma surgery in matched tissue samples, and 2) to characterize the acoustic variation that occurs in different tissue samples.

METHODS

This was a prospective observational proof-of-concept study. Recordings were attempted in 20 patients in order meet the accrual target of 10 patients with matched sound and tissue data. For each patient, three 30- to 60-second recordings were made at these sites: normal white matter, infiltrative margin, and tumor. Tissue samples at each site were then reviewed by experienced neuropathologists, and agreement with surgical identification was estimated with the kappa statistic. Acoustic parameters were characterized for each sample.

RESULTS

Data from 20 patients were analyzed. Patient-related or technical issues resulted in missing data for 10 patients, but the final 10 patients had both audio and tissue data for analysis. Among all tissue samples, fair agreement was observed between surgeon identification and actual pathology (κ = 0.24, standard error 0.096, p = 0.006). Acoustic data suggested that 1) the acoustic stimulus is broadband, 2) acoustic features are somewhat consistent within cases, 3) high-entropy values indicate irregularity of sound over time, and 4) bimodal pitch distributions could differentially reflect cues of interest.

CONCLUSIONS

This study supports the feasibility of collecting intraoperative data on acoustic features during glioma surgery, and it provides an example of how an analysis could be performed to compare different types of tissues.

Perivascular invasion of primary human glioblastoma cells in organotypic human brain slices: human cells migrating in human brain

INTRODUCTION

Glioblastoma (GBM) is an aggressive primary brain cancer. Lack of effective therapy is related to its highly invasive nature. GBM invasion has been studied with reductionist systems that do not fully recapitulate the cytoarchitecture of the brain. We describe a human-derived brain organotypic model to study the migratory properties of GBM IDH-wild type ex vivo.

METHODS

Non-tumor brain samples were obtained from patients undergoing surgery (n = 7). Organotypic brain slices were prepared, and green fluorescent protein (GFP)-labeled primary human GBM IDH-wild type cells (GBM276, GBM612, GBM965) were placed on the organotypic slice. Migration was evaluated via microscopy and immunohistochemistry.

RESULTS

After placement, cells migrated towards blood vessels; initially migrating with limited directionality, sending processes in different directions, and increasing their speed upon contact with the vessel. Once merged, migration speed decreased and continued to decrease with time (p < 0.001). After perivascular localization, migration is limited along the blood vessels in both directions. The percentage of cells that contact blood vessels and then continue to migrate along the vessel was 92.5% (- 3.9/ + 2.9)% while the percentage of cells that migrate along the blood vessel and leave was 7.5% (- 2.9/ + 3.9) (95% CI, Clopper-Pearson (exact); n = 256 cells from six organotypic cultures); these percentages are significantly different from the random (50%) null hypothesis (z = 13.6; p < 10-7). Further, cells increase their speed in response to a decrease in oxygen tension from atmospheric normoxia (20% O2) to anoxia (1% O2) (p = 0.033).

CONCLUSION

Human organotypic models can accurately study cell migration ex vivo. GBM IDH-wild type cells migrate toward the perivascular space in blood vessels and their migratory parameters change once they contact vascular structures and under hypoxic conditions. This model allows the evaluation of GBM invasion, considering the human brain microenvironment when cells are removed from their native niche after surgery.

Supramaximal Resection for Glioblastoma: Redefining the Extent of Resection Criteria and Its Impact on Survival

Glioblastomas (GBMs) are the most common and aggressive primary brain tumors, and despite advances in treatment, prognosis remains poor. The extent of resection has been widely recognized as a key factor affecting survival outcomes in GBM patients. The surgical principle of "maximal safe resection" has been widely applied to balance tumor removal and neurological function preservation. Historically, T1-contrast enhanced (T1CE) extent of resection has been the focus of research; however, the "supramaximal resection" concept has emerged, advocating for even greater tumor resection while maintaining neurological function. Recent studies have demonstrated potential survival benefits associated with resection beyond T1CE extent in GBMs. This review explores the developing consensus and newly established criteria for "supramaximal resection" in GBMs, with a focus on T2-extent of resection. Systematic reviews and meta-analyses on supramaximal resection are summarized, and the Response Assessment in Neuro-Oncology (RANO) resect group classification for extent of resection is introduced. The evolving understanding of the role of supramaximal resection in GBMs may lead to improved patient outcomes and more objective criteria for evaluating the extent of tumor resection.

A Systematic Review and Meta-Analysis of Supramarginal Resection versus Gross Total Resection in Glioblastoma: Can We Enhance Progression-Free Survival Time and Preserve Postoperative Safety?

To date, gross total resection (GTR) of the contrast-enhancing area of glioblastoma (GB) is the benchmark treatment regarding surgical therapy. However, GB infiltrates beyond those margins, and most tumors recur in close proximity to the initial resection margin. It is unclear whether a supramarginal resection (SMR) enhances progression-free survival (PFS) time without increasing the incidence of postoperative surgical complications. The aim of the present meta-analysis was to investigate SMR with regard to PFS and postoperative surgical complications. We searched for eligible studies comparing SMR techniques with conventional GTR in PubMed, Cochrane Library, Web of Science, and Medline databases. From 3158 initially identified records, 11 articles met the criteria and were included in our meta-analysis. Our results illustrate significantly prolonged PFS time in SMR compared with GTR (HR: 11.16; 95% CI: 3.07–40.52, p = 0.0002). The median PFS of the SMR arm was 8.44 months (95% CI: 5.18–11.70, p < 0.00001) longer than the GTR arm. The rate of postoperative surgical complications (meningitis, intracranial hemorrhage, and CSF leaks) did not differ between the SMR group and the GTR group. SMR resulted in longer median progression-free survival without a negative postoperative surgical risk profile. Multicentric prospective randomized trials with a standardized definition of SMR and analysis of neurologic functioning and health-related quality of life are justified and needed to improve the level of evidence.

Oncological and functional neurosurgery: Perspectives for the decade regarding diffuse gliomas

For decades, diffuse glioma (DG) studies mostly focused on oncological considerations, whereas functional outcomes received less attention. Currently, because overall survival has increased in DG, especially in low-grade glioma (overall survival > 15 years), quality of life including neurocognitive and behavioral aspects should be assessed and preserved more systematically, particularly regarding surgery. Indeed, early maximal tumor removal results in greater survival in both high-grade and low-grade gliomas, leading to propose "supra-marginal" resection, with excision of the peritumoral zone in diffuse neoplasms. To minimize functional risks while maximizing the extent of resection, traditional "tumor-mass resection" is replaced by "connectome-guided resection" conducted under awake mapping, taking into account inter-individual brain anatomo-functional variability. A better understanding of the dynamic interplay between DG progression and reactional neuroplastic mechanisms is critical to adapt a personalized multistage therapeutic strategy, with integration of functional neurooncological (re)operation(s) in a multimodal management scheme including repeated medical therapies. Because the therapeutic armamentarium remains limited, the aims of this paradigmatic shift are to predict one/several step(s) ahead glioma behavior, its modifications, and compensatory neural networks reconfiguration over time in order to optimize the onco-functional benefit of each treatment - either in isolation or in combination with others - in human beings bearing a chronic tumoral disease while enjoying an active familial and socio-professional life as close as possible to their expectations. Thus, new ecological endpoints such as return to work should be incorporated into future DG trials. "Preventive neurooncology" might also be envisioned, by proposing a screening policy to discover and treat incidental glioma earlier.

Update for astrocytomas: medical and surgical management considerations

Astrocytomas include a wide range of tumors with unique mutations and varying grades of malignancy. These tumors all originate from the astrocyte, a star-shaped glial cell that plays a major role in supporting functions of the central nervous system (CNS), including blood-brain barrier (BBB) development and maintenance, water and ion regulation, influencing neuronal synaptogenesis, and stimulating the immunological response. In terms of epidemiology, glioblastoma (GB), the most common and malignant astrocytoma, generally occur with higher rates in Australia, Western Europe, and Canada, with the lowest rates in Southeast Asia. Additionally, significantly higher rates of GB are observed in males and non-Hispanic whites. It has been suggested that higher levels of testosterone observed in biological males may account for the increased rates of GB. Hereditary syndromes such as Cowden, Lynch, Turcot, Li-Fraumeni, and neurofibromatosis type 1 have been linked to increased rates of astrocytoma development. While there are a number of specific gene mutations that may influence malignancy or be targeted in astrocytoma treatment, O 6-methylguanine-DNA methyltransferase (MGMT) gene function is an important predictor of astrocytoma response to chemotherapeutic agent temozolomide (TMZ). TMZ for primary and bevacizumab in the setting of recurrent tumor formation are two of the main chemotherapeutic agents currently approved in the treatment of astrocytomas. While stereotactic radiosurgery (SRS) has debatable implications for increased survival in comparison to whole-brain radiotherapy (WBRT), SRS demonstrates increased precision with reduced radiation toxicity. When considering surgical resection of astrocytoma, the extent of resection (EoR) is taken into consideration. Subtotal resection (STR) spares the margins of the T1 enhanced magnetic resonance imaging (MRI) region, gross total resection (GTR) includes the margins, and supramaximal resection (SMR) extends beyond the margin of the T1 and into the T2 region. Surgical resection, radiation, and chemotherapy are integral components of astrocytoma treatment.

The in vitro and in vivo anticancer activities of Antrodia salmonea through inhibition of metastasis and induction of ROS-mediated apoptotic and autophagic cell death in human glioblastoma cells

BACKGROUND

Antrodia salmonea (AS) exhibits anticancer activities against various cancers.

OBJECTIVE

This study investigated the anticancer activities of AS on human glioblastoma (GBM8401 and U87MG) cells both in vitro and in vivo and explained the underlying molecular mechanism.

METHODS

MTT, colony formation, migration/invasion assay, immunoblotting, immunofluorescence, TUNEL, Annexin V/PI staining, AO staining, GFP-LC3 transfection, TEM, qPCR, siLC3, DCFH2-DA assay, and xenografted-nude mice were used to assess the potential of AS therapy.

RESULTS

AS treatment retarded growth and suppressed colony formation in glioblastoma cells. AS attenuates EMT by suppressing invasion and migration, increasing E-cadherin expression, decreasing Twist, Snail, and N-cadherin expression, and inhibiting Wnt/β-catenin pathways in GBM8401 and U87MG cells. Furthermore, AS induced apoptosis by activating caspase-3, cleaving PARP, and dysregulating Bax and Bcl-2 in both cell lines. TUNEL assay and Annexin V/PI staining indicated AS-mediated late apoptosis. Interestingly, AS induced autophagic cell death by LC3-II accumulation, AVO formation, autophagosome GFP-LC3 puncta, p62/SQSTM1 expression, and ATG4B inhibition in GBM8401 and U87MG cells. TEM data revealed that AS favored autophagosome and autolysosome formation. The autophagy inhibitors 3-MA/CQ and LC3 knockdown suppressed AS-induced apoptosis in glioblastoma cells, indicating that the inhibition of autophagy decreased AS-induced apoptosis. Notably, the antioxidant N-acetylcysteine (NAC) inhibited AS-mediated ROS production and AS-induced apoptotic and autophagic cell death. Furthermore, AS induced ROS-mediated inhibition of the PI3K/AKT/mTOR signaling pathway. AS reduced the tumor burden in GBM8401-xenografted nude mice and significantly modulated tumor xenografts by inducing anti-EMT, apoptosis, and autophagy. AS could be a potential antitumor agent in human glioblastoma treatment.

Radical supramaximal resection for newly diagnosed left-sided eloquent glioblastoma: safety and improved survival over gross-total resection

OBJECTIVE

Supramaximal resection (SMR) has arisen as a possible surrogate to gross-total resection (GTR) to improve survival in newly diagnosed glioblastoma (nGBM). However, SMR has traditionally been limited to noneloquent regions and its feasibility in eloquent nGBM remains unclear. The authors conducted a retrospective multivariate propensity-matched analysis comparing survival outcomes for patients with left-sided eloquent nGBM undergoing SMR versus GTR.

METHODS

A retrospective review was performed of all patients at our institution who underwent SMR or GTR of a left-sided eloquent nGBM during the period from 2011 to 2020. All patients underwent some form of preoperative or intraoperative functional mapping and underwent awake or asleep craniotomy (craniotomy under general anesthesia); however, awake craniotomy was performed in the majority of patients and the focus of the study was SMR achieved via awake craniotomy and functional mapping with lesionectomy and additional peritumoral fluid attenuated inversion recovery (FLAIR) resection. Propensity scores were generated controlling for age, tumor location, and preoperative Karnofsky Performance Status (KPS) score with the nearest-neighbor algorithm.

RESULTS

A total of 102 patients (48 SMR, 54 GTR) were included in this study. The median overall survival (OS) and progression-free survival (PFS) for patients receiving SMR were 22.9 and 5.1 months, respectively. Propensity matching resulted in a final cohort of 27 SMR versus 27 GTR patients. SMR conferred improved OS (21.55 vs 15.49 months, p = 0.0098) and PFS (4.51 vs 3.59 months, p = 0.041) compared to GTR. There was no significant difference in postoperative complication rates or KPS score in SMR compared with GTR patients (p = 0.236 and p = 0.736, respectively). In patients receiving SMR, improved OS and PFS showed a dose-dependent relationship with extent of FLAIR resection (EOFR) on log-rank test for trend (p < 0.001).

CONCLUSIONS

SMR by means of awake craniotomy with functional mapping for left-sided eloquent nGBM is safe and confers a survival benefit compared to GTR obtained with lesionectomy alone while preserving postoperative neurological integrity. When tolerated, greater EOFR with SMR may be associated with improved survival.

Surgical Treatment of Glioblastoma: State-of-the-Art and Future Trends

Glioblastoma (GBM) is a highly aggressive disease and is associated with poor prognosis despite treatment advances in recent years. Surgical resection of tumor remains the main therapeutic option when approaching these patients, especially when combined with adjuvant radiochemotherapy. In the present study, we conducted a comprehensive literature review on the state-of-the-art and future trends of the surgical treatment of GBM, emphasizing topics that have been the object of recent study.

A consensus definition of supratotal resection for anatomically distinct primary glioblastoma: an AANS/CNS Section on Tumors survey of neurosurgical oncologists

INTRODUCTION

Supratotal resection (SpTR) of glioblastoma may be associated with improved survival, but published results have varied in part from lack of consensus on the definition and appropriate use of SpTR. A previous small survey of neurosurgical oncologists with expertise performing SpTR found resection 1-2 cm beyond contrast enhancement was an acceptable definition and glioblastoma involving the right frontal and bilateral anterior temporal lobes were considered most amenable to SpTR. The general neurosurgical oncology community has not yet confirmed the practicality of this definition.

METHODS

Seventy-six neurosurgical oncology members of the AANS/CNS Tumor Section were surveyed, representing 34.0% of the 223 members who were administered the survey. Participants were presented with 11 definitions of SpTR and rated each definition's appropriateness. Participants additionally reviewed magnetic resonance imaging for 10 anatomically distinct glioblastomas and assessed the tumor location's eloquence, perceived equipoise of enrolling patients in a randomized trial comparing gross total to SpTR, and their personal treatment plans.

RESULTS

Most neurosurgeons surveyed agree that gross total plus resection of some non-contrast enhancement (n = 57, 80.3%) or resection 1-2 cm beyond contrast enhancement (n = 52, 73.2%) are appropriate definitions for SpTR. Cases were divided into three anatomically distinct groups by perceived equipoise between gross total and SpTR. The best clinical trial candidates were thought to be right anterior temporal (n = 58, 76.3%) and right frontal (n = 55, 73.3%) glioblastomas.

CONCLUSION

Support exists among neurosurgical oncologists with varying familiarity performing SpTR to adopt the proposed consensus definition of SpTR of glioblastoma and to potentially investigate the utility of SpTR to treat right anterior temporal and right frontal glioblastomas in a clinical trial. A smaller proportion of general neurosurgical oncologists than SpTR experts would personally treat a left anterior temporal glioblastoma with SpTR.

Neurosurgical Clinical Trials for Glioblastoma: Current and Future Directions

The mainstays of glioblastoma treatment, maximal safe resection, radiotherapy preserving neurological function, and temozolomide (TMZ) chemotherapy have not changed for the past 17 years despite significant advances in the understanding of the genetics and molecular biology of glioblastoma. This review highlights the neurosurgical foundation for glioblastoma therapy. Here, we review the neurosurgeon’s role in several new and clinically-approved treatments for glioblastoma. We describe delivery techniques such as blood–brain barrier disruption and convection-enhanced delivery (CED) that may be used to deliver therapeutic agents to tumor tissue in higher concentrations than oral or intravenous delivery. We mention pivotal clinical trials of immunotherapy for glioblastoma and explain their outcomes. Finally, we take a glimpse at ongoing clinical trials and promising translational studies to predict ways that new therapies may improve the prognosis of patients with glioblastoma.

Use of virtual magnetic resonance imaging to compensate for brain shift during image-guided surgery: illustrative case

BACKGROUND

Maximal safe resection is the paramount objective in the surgical management of malignant brain tumors. It is facilitated through use of image-guided neuronavigation. Intraoperative image guidance systems use preoperative magnetic resonance imaging (MRI) as the navigational map. The accuracy of neuronavigation is limited by intraoperative brain shift and can become less accurate over the course of the procedure. Intraoperative MRI can compensate for dynamic brain shift but requires significant space and capital investment, often unavailable at many centers.

OBSERVATIONS

The authors described a case in which an image fusion algorithm was used in conjunction with an intraoperative computed tomography (CT) system to compensate for brain shift during resection of a brainstem hemorrhagic melanoma metastasis. Following initial debulking of the hemorrhagic metastasis, intraoperative CT was performed to ascertain extent of resection. An elastic image fusion (EIF) algorithm was used to create virtual MRI relative to both the intraoperative CT scan and preoperative MRI, which facilitated complete resection of the tumor while preserving critical brainstem anatomy.

LESSONS

EIF algorithms can be used with multimodal images (preoperative MRI and intraoperative CT) and create an updated virtual MRI data set to compensate for brain shift in neurosurgery and aid in maximum safe resection of malignant brain tumors.

IDH-wild-type glioblastoma cell density and infiltration distribution influence on supramarginal resection and its impact on overall survival: a mathematical model

OBJECTIVE

Recent studies have proposed resection of the T2 FLAIR hyperintensity beyond the T1 contrast enhancement (supramarginal resection [SMR]) for IDH-wild-type glioblastoma (GBM) to further improve patients' overall survival (OS). GBMs have significant variability in tumor cell density, distribution, and infiltration. Advanced mathematical models based on patient-specific radiographic features have provided new insights into GBM growth kinetics on two important parameters of tumor aggressiveness: proliferation rate (ρ) and diffusion rate (D). The aim of this study was to investigate OS of patients with IDH-wild-type GBM who underwent SMR based on a mathematical model of cell distribution and infiltration profile (tumor invasiveness profile).

METHODS

Volumetric measurements were obtained from the selected regions of interest from pre- and postoperative MRI studies of included patients. The tumor invasiveness profile (proliferation/diffusion [ρ/D] ratio) was calculated using the following formula: ρ/D ratio = (4π/3)2/3 × (6.106/[VT21/1 - VT11/1])2, where VT2 and VT1 are the preoperative FLAIR and contrast-enhancing volumes, respectively. Patients were split into subgroups based on their tumor invasiveness profiles. In this analysis, tumors were classified as nodular, moderately diffuse, or highly diffuse.

RESULTS

A total of 101 patients were included. Tumors were classified as nodular (n = 34), moderately diffuse (n = 34), and highly diffuse (n = 33). On multivariate analysis, increasing SMR had a significant positive correlation with OS for moderately and highly diffuse tumors (HR 0.99, 95% CI 0.98-0.99; p = 0.02; and HR 0.98, 95% CI 0.96-0.99; p = 0.04, respectively). On threshold analysis, OS benefit was seen with SMR from 10% to 29%, 10% to 59%, and 30% to 90%, for nodular, moderately diffuse, and highly diffuse, respectively.

CONCLUSIONS

The impact of SMR on OS for patients with IDH-wild-type GBM is influenced by the degree of tumor invasiveness. The authors' results show that increasing SMR is associated with increased OS in patients with moderate and highly diffuse IDH-wild-type GBMs. When grouping SMR into 10% intervals, this benefit was seen for all tumor subgroups, although for nodular tumors, the maximum beneficial SMR percentage was considerably lower than in moderate and highly diffuse tumors.

Supramarginal Resection for Glioblastoma: It Is Time to Set Boundaries! A Critical Review on a Hot Topic

Glioblastoma are the most common primary malignant brain tumors with a highly infiltrative behavior. The extent of resection of the enhancing component has been shown to be correlated to survival. Recently, it has been proposed to move the resection beyond the contrast-enhanced portion into the MR hyper intense tissue which typically surrounds the tumor, the so-called supra marginal resection (SMR). Though it should be associated with better overall survival (OS), a potential harmful resection must be avoided in order not to create new neurological deficits. Through this work, we aimed to perform a critical review of SMR in patients with Glioblastoma. A Medline database search and a pooled meta-analysis of HRs were conducted; 19 articles were included. Meta-analysis revealed a pooled OS HR of 0.64 (p = 0.052). SMR is generally considered as the resection of any T1w gadolinium-enhanced tumor exceeding FLAIR volume, but no consensus exists about the amount of volume that must be resected to have an OS gain. Equally, the role and the weight of several pre-operative features (tumor volume, location, eloquence, etc.), the intraoperative methods to extend resection, and the post-operative deficits, need to be considered more deeply in future studies.

Supratotal Resection of Gliomas With Awake Brain Mapping: Maximal Tumor Resection Preserving Motor, Language, and Neurocognitive Functions

Gliomas are a category of infiltrating glial neoplasms that are often located within or near the eloquent areas involved in motor, language, and neurocognitive functions. Surgical resection being the first-line treatment for gliomas, plays a crucial role in patient outcome. The role of the extent of resection (EOR) was evaluated, and we reported significant correlations between a higher EOR and better clinical prognosis of gliomas. However, recurrence is inevitable, even after aggressive tumor removal. Thus, efforts have been made to achieve extended tumor resection beyond contrast-enhanced mass lesions in magnetic resonance imaging (MRI)-defined areas, a process known as supratotal resection. Since it has been reported that tumor cells invade beyond regions visible as abnormal areas on MRI, imaging underestimates the true spatial extent of tumors. Furthermore, tumor cells have the potential to spread 10–20 mm away from the MRI-verified tumor boundary. The primary goal of supratotal resection is to maximize EOR and prolong the progression-free and overall survival of patients with gliomas. The available data, as well as our own work, clearly show that supratotal resection of gliomas is a feasible technique that has improved with the aid of awake functional mapping using intraoperative direct electrical stimulation. Awake brain mapping has enabled neurosurgeons achieve supratotal resection with favorable motor, language, and neurocognitive outcomes, ensuring a better quality of life in patients with gliomas.

Postmortem brain donations vs premortem surgical resections for glioblastoma research: viewing the matter as a whole

There have been limited improvements in diagnosis, treatment, and outcomes of primary brain cancers, including glioblastoma, over the past 10 years. This is largely attributable to persistent deficits in understanding brain tumor biology and pathogenesis due to a lack of high-quality biological research specimens. Traditional, premortem, surgical biopsy samples do not allow full characterization of the spatial and temporal heterogeneity of glioblastoma, nor capture end-stage disease to allow full evaluation of the evolutionary and mutational processes that lead to treatment resistance and recurrence. Furthermore, the necessity of ensuring sufficient viable tissue is available for histopathological diagnosis, while minimizing surgically induced functional deficit, leaves minimal tissue for research purposes and results in formalin fixation of most surgical specimens. Postmortem brain donation programs are rapidly gaining support due to their unique ability to address the limitations associated with surgical tissue sampling. Collecting, processing, and preserving tissue samples intended solely for research provides both a spatial and temporal view of tumor heterogeneity as well as the opportunity to fully characterize end-stage disease from histological and molecular standpoints. This review explores the limitations of traditional sample collection and the opportunities afforded by postmortem brain donations for future neurobiological cancer research.

Ventricle wall resection contributes to supramaximal resection and prognosis in SVZ-involved frontal gliomas: A single center retrospective study

BACKGROUND

Frontal glioma frequently invaded the subventricular zone (SVZ), which existed glioma stem cells and might be involved in the development of primary and recurrent gliomas. We attempted to identify whether ventricle wall resection contributed to the maximal extent of resection (EOR) and increased the patient's survival during frontal glioma resection.

METHODS

A total of 151 adult patients with primary SVZ-involved frontal gliomas were obtained between January 2012 and December 2018. We analyzed clinical data, EOR, complications and survival profiles between the ventricle wall group and the ventricle intact/opening group.

RESULTS

Applying ventricle wall removal had similar effect on the improvement of neurological function compared to applying ventricle intact/opening and did not increase the incidence of new neurological deficits, hydrocephalus, and ependymal dissemination in SVZ-involved frontal gliomas. A positive correlation was identified between EOR and the ventricle wall handling (r = 0.487, P < 0.001), which indicated that ventricle wall resection could contribute to achieve supramaximal resection. Applying supramaximal resection and ventricle wall resection could significantly prolong overall survival and progression free survival. Ventricle wall resection could be regarded as an independent prognostic indicator for both overall survival and progression free survival in patients with SVZ-involved frontal gliomas.

CONCLUSIONS

Ventricle wall resection in SVZ-involved frontal gliomas could contribute to achieve supramaximal resection and could significantly prolong overall survival and progression free survival.

Glioblastoma with deep supratentorial extension is associated with a worse overall survival

Glioblastoma (GBM) with deep-supratentorial extension (DSE) involving the thalamus, basal ganglia and corpus collosum, poses significant challenges for clinical management. In this study, we present our outcomes in patients who underwent resection of supratentorial GBM with associated involvement of deep brain structures. We conducted a retrospective review of patients who underwent resection of GBM at our institution between 2012 and 2018. A total of 419 patients were included whose pre-operative MRI scans were reviewed. Of these, 143 (34.1%) had GBM with DSE. There were similar rates of IDH-1 mutation (9% versus 7.6%, p = 0.940) and MGMT methylation status (35.7% versus 45.2%, p = 0.397) between the two cohorts. GBM patients without evidence of DSE had higher rates of radiographic gross total resection (GTR) compared to those with DSE: 70.6% versus 53.1%, respectively (p = 0.002). The presence of DSE was not associated with decreased progression-free survival (PFS) compared to patients without DSE (mean 7.24 ± 0.97 versus 8.89 ± 0.76 months, respectively; p = 0.276), but did portend a worse overall survival (OS) (mean 10.55 ± 1.04 versus 15.02 ± 1.05 months, respectively; p = 0.003). There was no difference in PFS or OS amongst DSE and non-DSE patients who underwent GTR, but patients who harbored DSE and underwent subtotal resection had worse OS (mean 8.26 ± 1.93 versus 12.96 ± 1.59 months, p = 0.03). Our study shows that GBM patients with DSE have lower OS compared to those without DSE. This survival difference appears to be primarily related to the limited surgical extent of resection owing to the neurological deficits that may be incurred with involvement of eloquent deep brain structures.

Neural stem cell delivery of an oncolytic adenovirus in newly diagnosed malignant glioma: a first-in-human, phase 1, dose-escalation trial

BACKGROUND

Malignant glioma is the most common and lethal primary brain tumour, with dismal survival rates and no effective treatment. We examined the safety and activity of NSC-CRAd-S-pk7, an engineered oncolytic adenovirus delivered by neural stem cells (NSCs), in patients with newly diagnosed high-grade glioma.

METHODS

This was a first-in-human, open-label, phase 1, dose-escalation trial done to determine the maximal tolerated dose of NSC-CRAd-S-pk7, following a 3 + 3 design. Patients with newly diagnosed, histologically confirmed, high-grade gliomas (WHO grade III or IV) were recruited. After neurosurgical resection, NSC-CRAd-S-pk7 was injected into the walls of the resection cavity. The first patient cohort received a dose starting at 6·25 × 10¹⁰ viral particles administered by 5·00 × 10⁷ NSCs, the second cohort a dose of 1·25 × 10¹¹ viral particles administered by 1·00 × 10⁸ NSCs, and the third cohort a dose of 1·875 × 10¹¹ viral particles administered by 1·50 × 10⁸ NSCs. No further dose escalation was planned. Within 10-14 days, treatment with temozolomide and radiotherapy was initiated. Primary endpoints were safety and toxicity profile and the maximum tolerated dose for a future phase 2 trial. All analyses were done in all patients who were included in the trial and received the study treatment and were not excluded from the study. Recruitment is complete and the trial is finished. The trial is registered with ClinicalTrials.gov, NCT03072134.

FINDINGS

Between April 24, 2017, and Nov 13, 2019, 12 patients with newly diagnosed, malignant gliomas were recruited and included in the safety analysis. Histopathological evaluation identified 11 (92%) of 12 patients with glioblastoma and one (8%) of 12 patients with anaplastic astrocytoma. The median follow-up was 18 months (IQR 14-22). One patient receiving 1·50 × 10⁸ NSCs loading 1·875 × 10¹¹ viral particles developed viral meningitis (grade 3) due to the inadvertent injection of NSC-CRAd-S-pk7 into the lateral ventricle. Otherwise, treatment was safe as no formal dose-limiting toxicity was reached, so 1·50 × 10⁸ NSCs loading 1·875 × 10¹¹ viral particles was recommended as a phase 2 trial dose. There were no treatment-related deaths. The median progression-free survival was 9·1 months (95% CI 8·5-not reached) and median overall survival was 18·4 months (15·7-not reached).

INTERPRETATION

NSC-CRAd-S-pk7 treatment was feasible and safe. Our immunological and histopathological findings support continued investigation of NSC-CRAd-S-pk7 in a phase 2/3 clinical trial.

FUNDING

US National Institutes of Health.

Feasibility, Safety and Impact on Overall Survival of Awake Resection for Newly Diagnosed Supratentorial IDH-Wildtype Glioblastomas in Adults

Simple Summary

A few studies have suggested the benefits of awake surgery by maximizing the extent of resection while preserving neurological function and improving survival in high-grade glioma patients. However, the histomolecular heterogeneity in these series, mixing grade 3 with grade 4, and IDH-mutated with IDH-wildtype gliomas, represents a major selection bias that may influence survival analyses. For the first time, in a large homogeneous single-institution cohort of newly diagnosed supratentorial IDH-wildtype glioblastoma in adult patients, we assessed feasibility, safety and efficacy of awake surgery using univariate, multivariate and case-matched analysis. Awake surgery was associated with higher resection rates, lower residual tumor rates, and more supratotal resections than asleep resections, allowed standard radiochemotherapy to be performed systematically within a short time between surgery and radiotherapy, and was an independent predictor of progression-free survival and overall survival in the whole series, together with the extent of resection, MGMT promoter methylation status, and standard.

Abstract

Background: Although awake resection using intraoperative cortico-subcortical functional brain mapping is the benchmark technique for diffuse gliomas within eloquent brain areas, it is still rarely proposed for IDH-wildtype glioblastomas. We have assessed the feasibility, safety, and efficacy of awake resection for IDH-wildtype glioblastomas. Methods: Observational single-institution cohort (2012–2018) of 453 adult patients harboring supratentorial IDH-wildtype glioblastomas who benefited from awake resection, from asleep resection, or from a biopsy. Case matching (1:1) criteria between the awake group and asleep group: gender, age, RTOG-RPA class, tumor side, location and volume and neurosurgeon experience. Results: In patients in the awake resection subgroup (n = 42), supratotal resections were more frequent (21.4% vs. 3.1%, p < 0.0001) while partial resections were less frequent (21.4% vs. 40.1%, p < 0.0001) compared to the asleep (n = 222) resection subgroup. In multivariable analyses, postoperative standard radiochemistry (aHR = 0.04, p < 0.0001), supratotal resection (aHR = 0.27, p = 0.0021), total resection (aHR = 0.43, p < 0.0001), KPS score > 70 (HR = 0.66, p = 0.0013), MGMT promoter methylation (HR = 0.55, p = 0.0031), and awake surgery (HR = 0.54, p = 0.0156) were independent predictors of overall survival. After case matching, a longer overall survival was found for awake resection (HR = 0.47, p = 0.0103). Conclusions: Awake resection is safe, allows larger resections than asleep surgery, and positively impacts overall survival of IDH-wildtype glioblastoma in selected adult patients.

Influence of supramarginal resection on survival outcomes after gross-total resection of IDH-wild-type glioblastoma

OBJECTIVE

The authors' goal was to use a multicenter, observational cohort study to determine whether supramarginal resection (SMR) of FLAIR-hyperintense tumor beyond the contrast-enhanced (CE) area influences the overall survival (OS) of patients with isocitrate dehydrogenase-wild-type (IDH-wt) glioblastoma after gross-total resection (GTR).

METHODS

The medical records of 888 patients aged ≥ 18 years who underwent resection of GBM between January 2011 and December 2017 were reviewed. Volumetric measurements of the CE tumor and surrounding FLAIR-hyperintense tumor were performed, clinical variables were obtained, and associations with OS were analyzed.

RESULTS

In total, 101 patients with newly diagnosed IDH-wt GBM who underwent GTR of the CE tumor met the inclusion criteria. In multivariate analysis, age ≥ 65 years (HR 1.97; 95% CI 1.01-2.56; p < 0.001) and contact with the lateral ventricles (HR 1.59; 95% CI 1.13-1.78; p = 0.025) were associated with shorter OS, but preoperative Karnofsky Performance Status ≥ 70 (HR 0.47; 95% CI 0.27-0.89; p = 0.006), MGMT promotor methylation (HR 0.63; 95% CI 0.52-0.99; p = 0.044), and increased percentage of SMR (HR 0.99; 95% CI 0.98-0.99; p = 0.02) were associated with longer OS. Finally, 20% SMR was the minimum percentage associated with beneficial OS (HR 0.56; 95% CI 0.35-0.89; p = 0.01), but > 60% SMR had no significant influence (HR 0.74; 95% CI 0.45-1.21; p = 0.234).

CONCLUSIONS

SMR is associated with improved OS in patients with IDH-wt GBM who undergo GTR of CE tumor. At least 20% SMR of the CE tumor was associated with beneficial OS, but greater than 60% SMR had no significant influence on OS.

Neuropsychological outcomes following supratotal resection for high-grade glioma: a review

PURPOSE

Supratotal resection (SpTR) of high-grade glioma (HGG), in which surgical removal of the tumor is extended outside the margins of the preoperative radiographic abnormality, has been suggested to improve overall survival (OS) and progression free survival (PFS) in patients harboring tumors of non-eloquent cortex when compared to gross total resection (GTR). While current literature demonstrates these findings without an increase in post-operative complications or neurological deficits, there remains a paucity of data examining the neuropsychological outcomes of SpTR for HGG. As quality of life dramatically influences survival rates in these patients, it is crucial for neurosurgeons, neuro-oncologists, and neuropsychiatrists to understand the behavioral and cognitive outcomes following SpTR, such that optimal treatment strategies can be tailored for each patient.

METHODS

We performed a comprehensive review of the available literature regarding survival, neuropsychological, and quality of life (QOL) outcomes following SpTR for HGG. We also review neuropsychological and QOL outcomes following GTR for HGG to serve as a framework for better understanding potential implications of SpTR.

RESULTS

While results are limited following SpTR for HGG, available data suggests similar outcomes to those seen in patients undergoing GTR of HGG, as well as low-grade glioma. These include a short-term decline in neuropsychological functioning post-surgically with a return to baseline across most neurocognitive domains occurring within several months. Memory and attention remain relatively diminished at long term follow-up.

CONCLUSIONS

Limited data exist examining postoperative cognitive and behavioral outcomes following SpTR for HGG. While the available data suggests a return to baseline for many neurocognitive domains, attention and memory deficits may persist. However, sample sizes are relatively small and have not been examined in the context of QOL and OS/PFS. More rigorous pre- and post-surgical neuropsychological assessment will help shed light on the long-term cognitive and behavioral effects of SpTR in the setting of HGG and inform clinical care and counseling when SpTR is considered.

Updated perspectives on awake neurosurgery with cognitive and emotional assessment for patients with low-grade gliomas

Introduction: Thanks to early extensive surgical resection combined with medical oncological therapies, life expectancy dramatically increased in low-grade glioma (LGG), with an overall survival currently over 15 years. Therefore, patients should be able to maintain valuable family and socio-professional activities.Areas covered: For many decades, cognitive and emotional aspects were neglected by surgical and medical neurooncologists. The goal of surgery was to avoid hemiplegia and/or aphasia, with no considerations regarding behavior. However, because LGG patients live longer, they must be cognitively and affectively able to make long-term projects. Preservation of higher-order functions should be considered systematically in LGG surgery by means of awake cognitive/emotional mapping and monitoring.Expert opinion: The aim is to incorporate recent advances in neurosciences, which proposed revisited models of cerebral processing relying on a meta-network perspective, into the pre-, intra- and postoperative procedure. In this connectomal approach, brain functions result from complex interactions within and between neural networks. This improved understanding of a constant instability of the neural system allows a better cognitive/emotional assessment before and after each treatment over years, in order to preserve personality and adaptive behavior for each LGG patient, based on his/her own definition of quality of life. It is time to create oncological neurosciences.

Advancing Imaging to Enhance Surgery: From Image to Information Guidance

Conventional magnetic resonance imaging (cMRI) has an established role as a crucial disease parameter in the multidisciplinary management of glioblastoma, guiding diagnosis, treatment planning, assessment, and follow-up. Yet, cMRI cannot provide adequate information regarding tissue heterogeneity and the infiltrative extent beyond the contrast enhancement. Advanced magnetic resonance imaging and PET and newer analytical methods are transforming images into data (radiomics) and providing noninvasive biomarkers of molecular features (radiogenomics), conveying enhanced information for improving decision making in surgery. This review analyzes the shift from image guidance to information guidance that is relevant for the surgical treatment of glioblastoma.