Return to Work Following Surgery for Incidental Diffuse Low-Grade Glioma: A Prospective Series With 74 Patients

The capability to successfully study and to be graduated in students who underwent awake surgical resection for a low-grade glioma

PURPOSE

Although low-grade glioma (LGG) patients are young with a long-life expectancy, their capacity to study received less attention. Here, the ability to complete studies and to pass examination in students following awake surgery (AS) was investigated.

METHODS

Students who underwent AS with mapping-based resection for LGG were consecutively selected, with analysis of their capability to continue studies and to obtain diploma.

RESULTS

Twenty-one patients fulfilled the inclusion criteria (5 men/16 women, mean age 22.9 ± 5.71 years), 4 high-school students and 17 university students - including 6 medical students, 4 masters (social work, management, human resource, civic service), 1 insurance BTS, business, engineering, secretarial, physiotherapy, police and accounting studies. The preoperative median KPS score was 95.2 ± 8.1. The mean tumor volume [TV] was 47.6 ± 49.6 cm3. No permanent deficits were generated (postoperative median KPS score 96.6 ± 5.7). The 21 patients continued their studies after surgery, with all patients except one (95%) who successfully passed their examination and were graduated. The mean EOR was 93.5 ± 10.8% (mean residual TV 5.8 ± 11.7 cm3). Pathology revealed 18 astrocytomas and 3 oligodendrogliomas. No early adjuvant therapy was administrated. Twelve patients (57.1%) underwent subsequent AS. The mean follow-up duration was 8.6 ± 4.4 years, with 16 patients (76.1%) still alive. In high-school students, the preoperative TV (p = 0.01) and postoperative TV (p = 0.03) were lower, with a higher EOR (p = 0.01).

CONCLUSION

This is the first series showing that AS preserves the ability to acquire new competences in students with LGG, who were able to complete their studies and to be graduated in 95% of cases.

Influence of supratotal resection on overall survival and progression of tumor in gliomas grade 2 and 3: a systematic review and meta-analysis

BACKGROUND

Recurrence after resection is a major factor in poor prognosis for grade 2 and 3 gliomas. The effect of Supratotal Resection (STR) on recurrence timing remains debated. This meta-analysis examines overall survival (OS) and tumor progression in grade 2 and 3 gliomas after supratotal resection.

METHODS

Studies on patients with grade II and III gliomas who underwent supratotal resection were included, with comparisons to subtotal, partial, and total resections. The primary outcomes were overall survival (OS) and tumor progression, while secondary outcomes included return-to-work (RTW) rates, malignant transformations and cognitive impairments.

RESULTS

We included 954 patients from 8 studies, mean age was 39 (± 16) years. The mean OS for patients undergoing supratotal resection was 17.45 (95% CI: 3.39 to 89.74, p < 0.05) compared to TR. The OR for RTW in the STR group versus TR group was 0.12 (95% CI: 0.01 to 1.28, p = 0.08). Tumor progression OR was, no statistical significantly, 0.15 (95% CI: 0.00 to 38.00, p = 0.5), and the likelihood of malignancy was reduced 0.03 (95% CI: 0.01 to 0.18, p < 0.01) compared to the TR group. In the immediate pos-operatory, when comparing STR with TR, the OR of language impairment was 5.47 (95% CI: 2.73 to 10.97, p < 0.01) and cognitive impairment was 0.38 (95% CI: 0.17 to 0.58). During the follow-up, the OR of language impairment was 0.68 (95% CI: 0.25 to 1.81, p = 0.44) and cognitive impairment was 0.34 (95% CI: 0.03 to 3.61, p = 0.37) comparing STR with TR.

CONCLUSION

Patients with grade 2 and 3 gliomas undergoing supratotal resection showed significantly higher overall survival, fewer malignant transformations and language impairments in immediate pos-operatory. While there was a trend towards higher return-to-work rates, progression of tumor and better cognitive status during the follow-up, it was not statistically significant. Further studies are needed for definitive conclusions.

CLINICAL TRIAL NUMBER

Not applicable.

The inferior fronto-occipital fasciculus: bridging phylogeny, ontogeny and functional anatomy

The inferior-fronto-occipital fasciculus is a long-range white matter tract that connects the prefrontal cortex with parietal, posterior temporal and occipital cortices. First identified in the nineteenth century through the pioneering studies of Mayo and Meynert using blunt dissection, its anatomy and function remain contentious topics. Structurally, its projections are well-documented in human blunt dissection and tractography literature, yet its existence has been questioned by tract-tracing studies in macaques. Functionally, while traditional results from direct white matter stimulation during awake surgery suggested a contribution to language, recent evidence from stimulation and lesion data may indicate a broader role in executive control, extending to attention, motor cognition, memory, reading, emotion recognition, and theory of mind. This review begins by examining anatomical evidence suggesting that the inferior fronto-occipital fasciculus evolved in non-human primates to connect temporal and occipital cortices to prefrontal regions involved in context-dependent selection of visual features for action. We then integrate developmental, electrophysiological, functional and anatomical evidence for the human inferior fronto-occipital fasciculus to propose it has a similar role in manipulation of visual features in our species-particularly when inhibition of overriding but task-irrelevant stimuli is required to prioritize a second, task-relevant stimulus. Next, we introduce a graded model in which dorsal (orbitofrontal, superior and middle frontal to precuneal, angular and supero-occipital projections) and ventral (inferior frontal to posterotemporal, basal temporal and infero-occipital) projections of the inferior fronto-occipital fasciculus support perceptual or conceptual control of visual representations for action, respectively. Leveraging this model, we address controversies in the current literature regarding language, motor cognition, attention and emotion under the unifying view of cognitive control. Finally, we discuss surgical implications for this model and its impact on predicting and preventing neurological deficits in neurosurgery.

The Alcatraz-Strategy: a roadmap to break the connectivity barrier in malignant brain tumours

In recent years, the discovery of functional and communicative cellular tumour networks has led to a new understanding of malignant primary brain tumours. In this review, the authors shed light on the diverse nature of cell-to-cell connections in brain tumours and propose an innovative treatment approach to address the detrimental connectivity of these networks. The proposed therapeutic outlook revolves around three main strategies: (a) supramarginal resection removing a substantial portion of the communicating tumour cell front far beyond the gadolinium-enhancing tumour mass, (b) morphological isolation at the single cell level disrupting structural cell-to-cell contacts facilitated by elongated cellular membrane protrusions known as tumour microtubes (TMs), and (c) functional isolation at the single cell level blocking TM-mediated intercellular cytosolic exchange and inhibiting neuronal excitatory input into the malignant network. We draw an analogy between the proposed therapeutic outlook and the Alcatraz Federal Penitentiary, where inmates faced an impassable sea barrier and experienced both spatial and functional isolation within individual cells. Based on current translational efforts and ongoing clinical trials, we propose the Alcatraz-Strategy as a promising framework to tackle the harmful effects of cellular brain tumour networks.

Global health status and fatigue score in isocitrate dehydrogenase-mutant diffuse glioma grades 2 and 3: A longitudinal population-based study from surgery to 12-month follow-up

Background

At the group level, health-related quality of life (HRQoL) in patients with IDH-mutant diffuse glioma grades 2 and 3 seems to remain stable over time. However, clinical experience indicates that there are patients with unfavorable outcomes on key HRQoL subdomains. The aim of this longitudinal population-based study, following patients over a period of 12 months from surgery, was to describe individual-level data on global health status and fatigue score and explore possible predictors of deterioration.

Methods

All patients undergoing surgery for presumed glioma grades 2 or 3 at the Sahlgrenska University Hospital during 2017-2022, were screened for the study. Patients were invited to complete the European Organization of Research and Treatment of Cancer core questionnaires and brain module at baseline, 3 and 12 months postoperatively. Data is reported with respect to minimal clinical important difference (MCID).

Results

We included 51 patients with IDH-mutant diffuse glioma grades 2 or 3. There was no difference in group-level data of either global health status or fatigue score from baseline to the 12-month follow-up (P-value > .05). Unfavorable individual changes (beyond MCID) in global health status and fatigue score were observed in 12 and in 17 patients, respectively (23.5% and 33.3%). A lower proportion of proton radiotherapy was found in patients with unfavorable changes in fatigue (10/15, 66.7%) compared to all other patients undergoing radiotherapy (22/23, 95.7%, P-value .03).

Conclusions

Deterioration beyond MCID was seen in approximately one-third of patients. Changes in global health status could not be predicted, but changes in fatigue may be influenced by tumor-targeted and symptomatic treatment.

An update on tests used for intraoperative monitoring of cognition during awake craniotomy

PURPOSE

Mapping higher-order cognitive functions during awake brain surgery is important for cognitive preservation which is related to postoperative quality of life. A systematic review from 2018 about neuropsychological tests used during awake craniotomy made clear that until 2017 language was most often monitored and that the other cognitive domains were underexposed (Ruis, J Clin Exp Neuropsychol 40(10):1081-1104, 218). The field of awake craniotomy and cognitive monitoring is however developing rapidly. The aim of the current review is therefore, to investigate whether there is a change in the field towards incorporation of new tests and more complete mapping of (higher-order) cognitive functions.

METHODS

We replicated the systematic search of the study from 2018 in PubMed and Embase from February 2017 to November 2023, yielding 5130 potentially relevant articles. We used the artificial machine learning tool ASReview for screening and included 272 papers that gave a detailed description of the neuropsychological tests used during awake craniotomy.

RESULTS

Comparable to the previous study of 2018, the majority of studies (90.4%) reported tests for assessing language functions (Ruis, J Clin Exp Neuropsychol 40(10):1081-1104, 218). Nevertheless, an increasing number of studies now also describe tests for monitoring visuospatial functions, social cognition, and executive functions.

CONCLUSIONS

Language remains the most extensively tested cognitive domain. However, a broader range of tests are now implemented during awake craniotomy and there are (new developed) tests which received more attention. The rapid development in the field is reflected in the included studies in this review. Nevertheless, for some cognitive domains (e.g., executive functions and memory), there is still a need for developing tests that can be used during awake surgery.

Focus on current and emerging treatment options for glioma: A comprehensive review

This comprehensive review delves into the current updates and challenges associated with the management of low-grade gliomas (LGG), the predominant primary tumors in the central nervous system. With a general incidence rate of 5.81 per 100000, gliomas pose a significant global concern, necessitating advancements in treatment techniques to reduce mortality and morbidity. This review places a particular focus on immunotherapies, discussing promising agents such as Zotiraciclib and Lerapolturev. Zotiraciclib, a CDK9 inhibitor, has demonstrated efficacy in glioblastoma treatment in preclinical and clinical studies, showing its potential as a therapeutic breakthrough. Lerapolturev, a viral immunotherapy, induces inflammation in glioblastoma and displays positive outcomes in both adult and pediatric patients. Exploration of immunotherapy extends to Pembrolizumab, Nivolumab, and Entrectinib, revealing the challenges and variabilities in patient responses. Despite promising preclinical data, the monoclonal antibody Depatuxizumab has proven ineffective in glioblastoma treatment, emphasizing the critical need to understand resistance mechanisms. The review also covers the success of radiation therapy in pediatric LGG, with evolving techniques, such as proton therapy, showing potential improvements in patient quality of life. Surgical treatment is discussed in the context of achieving a balance between preserving the patient's quality of life and attaining gross total resection, with the extent of surgical resection significantly influencing the survival outcomes. In addition to advancements in cancer vaccine development, this review highlights the evolving landscape of LGG treatment, emphasizing a shift toward personalized and targeted therapies. Ongoing research is essential for refining strategies and enhancing outcomes in the management of LGG.

Verbal fluency predicts work resumption after awake surgery in low-grade glioma patients

BACKGROUND

Resuming professional activity after awake surgery for diffuse low-grade glioma (DLGG) is an important goal, which is not reached in every patient. Cognitive deficits can occur and persist after surgery. In this study, we analyzed the impact of mild cognitive impairments on the work resumption.

METHODS

Fifty-four surgeries (including five redo surgeries) performed between 2012 and 2020 for grade 2 (45) and 3 (nine) DLGG in 49 professionally active patients (mean age 40 [range 23-58.) were included. We retrospectively extracted the results of semantic and phonemic verbal fluency tests from preoperative and 4-month postoperative cognitive assessments. Patients were interviewed about their working life after surgery, between April and June 2021.

RESULTS

Patients (85%) returned to work, most within 3 to 6 months. Patients (76%) reported subjective complaints (primarily fatigue). Self-reported symptoms and individual and clinical variables had no impact on the work resumption. Late-postoperative average Z-scores in verbal fluency tasks were significantly lower than preoperative for the entire cohort (Wilcoxon test, p < 0.001 for semantic and p = 0.008 for phonemic fluency). The decrease in Z-scores was significantly greater (Mann Whitney U-test, semantic, p = 0.018; phonemic, p = 0.004) in the group of patients who did not return to work than in the group of patients who did.

CONCLUSION

The proportion of patients returning to work was comparable to similar studies. A decrease in verbal fluency tasks could predict the inability to return to work.

Oncological and functional outcomes support early resection of incidental IDH-mutated glioma

PURPOSE

The main objective was to assess the neuropsychological, epileptical, and oncological outcomes in a series of patients operated on for a IDH-mutated diffuse low-grade glioma (DLGG) of incidental discovery (iDLGG).

METHODS

We retrospectively reviewed a consecutive series of surgically treated adults with DLGG and selected cases incidentally discovered. Tumor volumes, growth rates, and extents of resection (EOR) were assessed by volumetric measures of fluid-attenuated inversion recovery magnetic resonance imaging. The data on oncological, functional, and epileptical results were retrieved from the patients' digital files.

RESULTS

Among all patients with DLGG resected at our center between June 2011 and April 2022, we found eleven cases with an incidental discovery. Resection was supratotal, gross total, and subtotal in 45.5%, 26.4%, and 18.1% of cases, respectively. The rate of epileptic seizures after the surgery was 9.1%. There were 45.4% of patients that had tumor progressions and the overall mean time to tumor progression was 42 months. After the surgery, 3 (27.3%) patients had mild neurocognitive deteriorations, which impeded the return to work in one patient (9.1%). There were no differences with previous series regarding clinical, radiological, and molecular characteristics. Similar results were also found for functional, surgical, epileptical, and oncological outcomes.

CONCLUSION

Although the right approach for iDLGG is still a matter of debate, our data support the safety and effectiveness of early surgical resection. More studies are needed to firmly ground this early "preventive" surgery approach.

Development of an educational method to rethink and learn oncological brain surgery in an "a la carte" connectome-based perspective

BACKGROUND

Understanding the structural connectivity of white matter tracts (WMT) and their related functions is a prerequisite to implementing an "a la carte" "connectomic approach" to glioma surgery. However, accessible resources facilitating such an approach are lacking. Here we present an educational method that is readily accessible, simple, and reproducible that enables the visualization of WMTs on individual patient images via an atlas-based approach.

METHODS

Our method uses the patient's own magnetic resonance imaging (MRI) images and consists of three main steps: data conversion, normalization, and visualization; these are accomplished using accessible software packages and WMT atlases. We implement our method on three common cases encountered in glioma surgery: a right supplementary motor area tumor, a left insular tumor, and a left temporal tumor.

RESULTS

Using patient-specific perioperative MRIs with open-sourced and co-registered atlas-derived WMTs, we highlight the critical subnetworks requiring specific surgical monitoring identified intraoperatively using direct electrostimulation mapping with cognitive monitoring. The aim of this didactic method is to provide the neurosurgical oncology community with an accessible and ready-to-use educational tool, enabling neurosurgeons to improve their knowledge of WMTs and to better learn their oncologic cases, especially in glioma surgery using awake mapping.

CONCLUSIONS

Taking no more than 3-5 min per patient and irrespective of their resource settings, we believe that this method will enable junior surgeons to develop an intuition, and a robust 3-dimensional imagery of WMT by regularly applying it to their cases both before and after surgery to develop an "a la carte" connectome-based perspective to glioma surgery.

Brain Plasticity Profiling as a Key Support to Therapeutic Decision-Making in Low-Grade Glioma Oncological Strategies

The ability of neural circuits to compensate for damage to the central nervous system is called postlesional plasticity. In diffuse low-grade gliomas (LGGs), a crosstalk between the brain and the tumor activates modulations of plasticity, as well as tumor proliferation and migration, by means of paracrine and electrical intercommunications. Such adaptative mechanisms have a major impact on the benefits and risks of oncological treatments but are still disregarded by current neuro-oncological guidelines. In this review, the authors first aimed to highlight clinical, radiological, and oncological markers that robustly reflect the plasticity potentials and limitations in LGG patients, including the location of the tumor and the degree of critical white matter tract infiltration, the velocity of tumor expansion, and the reactional changes of neuropsychological performances over time. Second, the interactions between the potential/limitations of cerebral plasticity and the efficacy/tolerance of treatment options (i.e., surgery, chemotherapy, and radiotherapy) are reviewed. Finally, a longitudinal and multimodal treatment approach accounting for the evolutive profiles of brain plasticity is proposed. Such an approach integrates personalized predictive models of plasticity potentials with a step-by-step therapeutic decision making and supports onco-functional balanced strategies in patients with LGG, with the ultimate aim of optimizing overall survival and quality of life.

Advances in molecular and imaging biomarkers in lower-grade gliomas

INTRODUCTION

Lower-grade (grade 2-3) gliomas (LGGs) constitutes a group of primary brain tumors with variable clinical behaviors and treatment responses. Recent advancements in molecular biology have redefined their classification, and novel imaging modalities emerged for the noninvasive diagnosis and follow-up.

AREAS COVERED

This review comprehensively analyses the current knowledge on molecular and imaging biomarkers in LGGs. Key molecular alterations, such as IDH mutations and 1p/19q codeletion, are discussed for their prognostic and predictive implications in guiding treatment decisions. Moreover, the authors explore theranostic biomarkers for the potential of tailored therapies. Additionally, they also describe the utility of advanced imaging modalities, including widely available techniques, as dynamic susceptibility contrast perfusion-weighted imaging and less validated, emerging approaches, for the noninvasive LGGs characterization and follow-up.

EXPERT OPINION

The integration of molecular markers enhanced the stratification of LGGs, leading to the new concept of integrated histomolecular classification. While the IDH mutation is an established key prognostic and predictive marker, recent results from IDH inhibitors trials showed its potential value as a theranostic marker. In this setting, advanced MRI techniques such as 2-D-hydroxyglutarate spectroscopy are very promising for the noninvasive diagnosis and monitoring of LGGs. This progress offers exciting prospects for personalized medicine and improved treatment outcomes in LGGs.

Supratotal Surgical Resection for Low-Grade Glioma: A Systematic Review

Low-grade gliomas (LGGs) are optimally treated with up-front maximal safe surgical resection, typically defined as maximizing the extent of tumor resection while minimizing neurologic risks of surgery. Supratotal resection of LGG may improve outcomes beyond gross total resection by removing tumor cells invading beyond the tumor border as defined on MRI. However, the evidence regarding supratotal resection of LGG, in terms of impact on clinical outcomes, such as overall survival and neurologic morbidities, remains unclear. Authors independently searched the PubMed, Medline, Ovid, CENTRAL (Cochrane Central Register of Controlled Trials), and Google Scholar databases for studies evaluating overall survival, time to progression, seizure outcomes, and postoperative neurologic and medical complications of supratotal resection/FLAIRectomy of WHO-defined LGGs. Papers in languages other than English, lacking full-text availability, evaluating supratotal resection of WHO-defined high-grade gliomas only, and nonhuman studies were excluded. After literature search, reference screening, and initial exclusions, 65 studies were screened for relevancy, of which 23 were evaluated via full-text review, and 10 were ultimately included in the final evidence review. Studies were evaluated for quality using the MINORS criteria. After data extraction, a total of 1301 LGG patients were included in the analysis, with 377 (29.0%) undergoing supratotal resection. The main measured outcomes were extent of resection, pre- and postoperative neurological deficits, seizure control, adjuvant treatment, neuropsychological outcomes, ability to return to work, progression-free survival, and overall survival. Overall, low- to moderate-quality evidence was supportive of aggressive, functional boundary-based resection of LGGs due to improvements in progression-free survival and seizure control. The published literature provides a moderate amount of low-quality evidence supporting supratotal surgical resection along functional boundaries for low-grade glioma. Among patients included in this analysis, the occurrence of postoperative neurological deficits was low, and nearly all patients recovered within 3 to 6 months after surgery. Notably, the surgical centers represented in this analysis have significant experience in glioma surgery in general, and supratotal resection specifically. In this setting, supratotal surgical resection along functional boundaries appears to be appropriate for both symptomatic and asymptomatic low-grade glioma patients. Larger clinical studies are needed to better define the role of supratotal resection in LGG.

A single-center prospective study regarding time to return to activities of daily living after craniotomy for brain tumors

BACKGROUND

There are few studies on the time to return to activities of daily living (ADL) after craniotomy in patients with brain tumors. This study aimed to investigate the duration before returning to ADLs after craniotomy for brain tumors and present data that can provide information and guidelines on the appropriate time needed.

METHODS

Patients (n = 183 of 234) who underwent craniotomy for brain tumors between April 2021 and July 2021 capable of self-care upon discharge were enrolled, and data of 158 were collected. The start time of 85 ADL items was prospectively investigated for 4 months postoperatively, using the self-recording sheet.

RESULTS

Over 89% and 87% of the patients performed basic ADL items within a month and instrumental ADL items within 2 months (medians: within 18 days), except for a few. Regarding work, 50% of the patients returned within 4 months. Washing hair with a wound was performed at 18 days of median value, after 4 months of dyeing/perming hair, 6 days of drinking coffee/tea, after 4 months of air travel, and 40 days of complementary and alternative medicine. In patients with infratentorial tumors or surgical problems, return times were much later for various items.

CONCLUSIONS

It is possible to provide practical information and guidelines on the duration to return to ADL after craniotomy in brain tumor patients. These study findings also reduce uncertainty about recovery and daily life and help patients return to their daily life at the appropriate time, thereby maintaining function and daily well-being after surgery.

Occurrence of non-central nervous system cancers during postoperative follow-up of patients who underwent surgery for a WHO grade II glioma: implications for therapeutic management

PURPOSE

Survival is currently prolonged in WHO grade II glioma (GIIG). Although exceptionally described, long-term survivors may develop second primary cancers outside the central nervous system (CNS). Here, a consecutive series explored the association between non-CNS cancers (nCNSc) and GIIG in patients who underwent glioma resection.

METHODS

Inclusion criteria were adult patients operated for a GIIG who experienced nCNSc following cerebral surgery.

RESULTS

Nineteen patients developed nCNSc after GIIG removal (median time 7.3 years, range 0.6-17.3 years), including breast cancers (n = 6), hematological cancers (n = 2), liposarcomas (n = 2), lung cancers (n = 2), kidney cancers (n = 2), cardia cancers (n = 2), bladder cancer (n = 1), prostate cancer (n = 1) and melanoma (n = 1). The mean extent of GIIG resection was 91.68 ± 6.39%, with no permanent neurological deficit. Fifteen oligodendrogliomas and 4 IDH-mutated astrocytomas were diagnosed. Adjuvant treatment was administrated in 12 patients before nCNSc onset. Moreover, 5 patients underwent reoperation. The median follow-up from initial GIIG surgery was 9.4 years (range 2.3-19.9 years). Nine patients (47%) died in this period. The 7 patients who deceased from the second tumor were significantly older at nCNSc diagnosis than the 2 patients who died from the glioma (p = 0.022), with a longer time between GIIG surgery and the occurrence of nCNSc (p = 0.046).

CONCLUSION

This is the first study investigating the combination between GIIG and nCNSc. Because GIIG patients are living longer, the risk to experience second neoplasm and to die from it is increasing, especially in older patients. Such data may be helpful for tailoring the therapeutic strategy in neurooncological patients developing several cancers.

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.

Molecular characteristics of incidental lower-grade glioma for treatment decision-making

OBJECTIVE

Several limitations are associated with the early diagnosis and treatment of incidental lower-grade glioma (iLGG), and due to its unknown molecular features, its management is categorized as either the "wait-and-see" strategy or immediate treatment. Therefore, in this study the authors explored iLGG's clinical and molecular landscape to improve its management.

METHODS

The authors retrospectively assessed the differences between the molecular and clinical characteristics of iLGG and symptomatic lower-grade glioma (sLGG) samples filtered based on symptom data corresponding to The Cancer Genome Atlas cohort with mutations. Thereafter, genomic and transcriptomic analysis was performed.

RESULTS

There was no significant difference between iLGG and sLGG with respect to mutation status; however, there was an increase in the interaction between major mutations in sLGG, depending on the histological subtype and the IDH1 mutation status. Furthermore, the IDH1 mutation characteristics corresponding to wild-type glioma were much more obvious in sLGG than in iLGG. Additionally, in sLGG, genes associated with malignancy, including cell proliferation-related, cell migration-related, epithelial-to-mesenchymal transition-related, and negative regulation of cell death-related genes, were significantly upregulated, and groups showing higher expression levels of these genes were associated with worse prognosis. Also, 8 of the 75 identified upregulated genes showed positive correlation with resistance to the drugs that are normally used for glioma treatment, including procarbazine, carmustine, vincristine, and temozolomide.

CONCLUSIONS

The new insights regarding the different molecular features of iLGG and sLGG indicated that the immediate management of iLGG could result in better prognosis than the wait-and-see strategy.

Association of extent of resection and functional outcomes in diffuse low-grade glioma: systematic review & meta-analysis

BACKGROUND

Surgical resection offers survival benefits in patients with diffuse low-grade glioma (DLGG) but its association with functional outcomes is uncertain. This systematic review assessed functional outcomes associated with extent of resection (EoR) in adults with DLGG.

METHODS

We searched Medline, Embase and CENTRAL on the 19th of February 2021 for observational studies reporting functional outcomes after surgical resection for patients aged ≥ 18 years with a new diagnosis of supratentorial DLGG according to any World Health Organization classification of primary brain tumors. The Newcastle-Ottawa Scale (NOS) informed our risk of bias assessments. The proportion of patients returning to work within 12 months entered a random-effects meta-analysis. PROSPERO registration number CRD42021238387.

RESULTS

There were seven eligible moderate to high-quality (NOS > 6) observational studies identified from 1,183 records involving 234 patients with DLGG. Functional outcomes reported included neurocognition (n = 2 studies), performance status (n = 3), quality of life (QoL) (n = 1) and return to work (n = 6). The proportion of patients who returned to work within 12 months of surgery was 84% (95% confidence interval [CI] 50-96%, I-squared = 38%, 5 studies) for gross total resection, 66% (95% CI 14-96%, I2 = 57%, 5 studies) for subtotal resection, and 31% (95% CI 4-82%, I2 = 0%, 4 studies) for partial resection. There was insufficient data on other functional outcomes for quantitative synthesis.

CONCLUSION

A higher proportion of DLGG patients returned to work following gross total resection compared with those who had a subtotal or partial resection. Further studies with standardized assessments can clarify the association between EoR and different functional outcomes.

Dynamics in cognition and health-related quality of life in grade 2 and 3 gliomas after surgery

BACKGROUND

The focus of clinical management and research in gliomas has been on survival, but the interest in the treatment effects on cognition and health-related quality of life (HRQoL) is emerging. The primary aim of this study was to investigate the dynamics in cognition after brain tumor surgery for astrocytomas and oligodendrogliomas grade 2 and 3. The secondary aim was to investigate the association of postoperative changes in cognition with changes HRQoL.

METHODS

In this observational study, 48 patients operated for an astrocytoma or oligodendrogliomas, grade 2 or 3, at the Department of Neurosurgery, Uppsala, Sweden, 2016-2021, were included. Cognitive and language skills were assessed with a selected test battery and HRQoL was patient-reported as assessed with RAND-36 pre- and approximately 3 months postoperatively.

RESULTS

There was a significant postoperative decrease in attention span and verbal learning, but the patients improved in the test for visual memory. There was no change in visual attention, executive function, verbal memory, visual organization and construction, verbal fluency, and confrontation naming. The RAND-36 variables physical function, role physical, general health, vitality, and social functioning decreased significantly after surgery. Patients operated for tumor recurrence exhibited greater deterioration in attention and a greater extent of resection correlated with a less pronounced decrease in verbal memory, but there were otherwise weak associations between the dynamics in cognition and patient-, tumor-, and treatment-variables. A decline in cognitive variables was not associated with worse HRQoL.

CONCLUSIONS

Although both several cognitive and HRQoL domains deteriorated postoperatively, these changes did not correlate with each other. This highlights the complexity of cognitive and HRQoL dynamics in the early postoperative phase.

The need to consider return to work as a main outcome in patients undergoing surgery for diffuse low-grade glioma: a systematic review

OBJECTIVE

For a long time, return to work (RTW) has been neglected in patients harboring a diffuse low-grade glioma (LGG). However, a majority of LGG patients worked at time of diagnosis. Moreover, these patients now live longer given current treatment paradigms, especially thanks to early maximal surgery.

METHODS

We systematically searched available medical databases for studies that reported data on RTW in patients who underwent resection for LGG.

RESULTS

A total of 30 studies were selected: 19 considered RTW (especially rate and timing) as an outcome and 11 used scales of health-related quality of life (HRQoL) which included work-related aspects. Series that considered RTW as a main endpoint were composed of 1014 patients, with postoperative RTW rates ranging from 31 to 97.1% (mean 73.1%). Timing to RTW ranged from 15 days to 22 months (mean 6.3 months). Factors related to an increased proportion of RTW were: younger age, better neurologic status, having a white-collar occupation, working pre-operatively, being the sole breadwinner, the use of awake surgery, and greater extent of resection. Female sex, older age, poor neurologic status, pre-operative history of work absences, slow lexical access speed, and postoperative seizures were negatively related to RTW. No studies that used HRQoL scales directly investigated RTW rate or timing.

CONCLUSIONS

RTW was scarcely analyzed in LGG patients who underwent resection. However, because they are usually young, with no or only mild functional deficits and have a longer life expectancy, postoperative RTW should be assessed more systematically and accurately as a main outcome. As majority (61.5-100%) of LGG patients were working at time of surgery, the responsibility of neurosurgeons is to bring these patients back to their previous activities according to his/her wishes. RTW might also be included as a critical endpoint for future prospective studies and randomized control trials on LGGs.

A Personalized Longitudinal Strategy in Low-Grade Glioma Patients: Predicting Oncological and Neural Interindividual Variability and Its Changes over Years to Think One Step Ahead

Diffuse low-grade glioma (LGG) is a rare cerebral cancer, mostly involving young adults with an active life at diagnosis. If left untreated, LGG widely invades the brain and becomes malignant, generating neurological worsening and ultimately death. Early and repeat treatments for this incurable tumor, including maximal connectome-based surgical resection(s) in awake patients, enable postponement of malignant transformation while preserving quality of life owing to constant neural network reconfiguration. Due to considerable interindividual variability in terms of LGG course and consecutive cerebral reorganization, a multistage longitudinal strategy should be tailored accordingly in each patient. It is crucial to predict how the glioma will progress (changes in growth rate and pattern of migration, genetic mutation, etc.) and how the brain will adapt (changes in patterns of spatiotemporal redistribution, possible functional consequences such as epilepsy or cognitive decline, etc.). The goal is to anticipate therapeutic management, remaining one step ahead in order to select the optimal (re-)treatment(s) (some of them possibly kept in reserve), at the appropriate time(s) in the evolution of this chronic disease, before malignization and clinical worsening. Here, predictive tumoral and non-tumoral factors, and their ever-changing interactions, are reviewed to guide individual decisions in advance based on patient-specific markers, for the treatment of LGG.

The Aftercare Survey: Assessment and intervention practices after brain tumor surgery in Europe

Background

People with gliomas need specialized neurosurgical, neuro-oncological, psycho-oncological, and neuropsychological care. The role of language and cognitive recovery and rehabilitation in patients' well-being and resumption of work is crucial, but there are no clear guidelines for the ideal timing and character of assessments and interventions. The goal of the present work was to describe representative (neuro)psychological practices implemented after brain surgery in Europe.

Methods

An online survey was addressed to professionals working with individuals after brain surgery. We inquired about the assessments and interventions and the involvement of caregivers. Additionally, we asked about recommendations for an ideal assessment and intervention plan.

Results

Thirty-eight European centers completed the survey. Thirty of them offered at least one postsurgical (neuro)psychological assessment, mainly for language and cognition, especially during the early recovery stage and at long term. Twenty-eight of the participating centers offered postsurgical therapies. Patients who stand the highest chances of being included in evaluation and therapy postsurgically are those who underwent awake brain surgery, harbored a low-grade glioma, or showed poor recovery. Nearly half of the respondents offer support programs to caregivers, and all teams recommend them. Treatments differed between those offered to individuals with low-grade glioma vs those with high-grade glioma. The figure of caregiver is not yet fully recognized in the recovery phase.

Conclusion

We stress the need for more complete rehabilitation plans, including the emotional and health-related aspects of recovery. In respondents' opinions, assessment and rehabilitation plans should also be individually tailored and goal-directed (eg, professional reinsertion).

Repeated Awake Surgical Resection(s) for Recurrent Diffuse Low-Grade Gliomas: Why, When, and How to Reoperate?

Early maximal surgical resection is the first treatment in diffuse low-grade glioma (DLGG), because the reduction of tumor volume delays malignant transformation and extends survival. Awake surgery with intraoperative mapping and behavioral monitoring enables to preserve quality of life (QoL). However, because of the infiltrative nature of DLGG, relapse is unavoidable, even after (supra)total resection. Therefore, besides chemotherapy and radiotherapy, the question of reoperation(s) is increasingly raised, especially because patients with DLGG usually enjoy a normal life with long-lasting projects. Here, the purpose is to review the literature in the emerging field of iterative surgeries in DLGG. First, long-term follow-up results showed that patients with DLGG who underwent multiple surgeries had an increased survival (above 17 years) with preservation of QoL. Second, the criteria guiding the decision to reoperate and defining the optimal timing are discussed, mainly based on the dynamic intercommunication between the glioma relapse (including its kinetics and pattern of regrowth) and the reactional cerebral reorganization—i.e., mechanisms underpinning reconfiguration within and across neural networks to enable functional compensation. Third, how to adapt medico-surgical strategy to this individual spatiotemporal brain tumor interplay is detailed, by considering the perpetual changes in connectome. These data support early reoperation in recurrent DLGG, before the onset of symptoms and before malignant transformation. Repeat awake resection(s) should be integrated in a global management including (neo)adjuvant medical treatments, to enhance long-lasting functional and oncological outcomes. The prediction of potential and limitation of neuroplasticity at each step of the disease must be improved to anticipate personalized multistage therapeutic attitudes.

Constant Multi-Tasking With Time Constraint to Preserve Across-Network Dynamics Throughout Awake Surgery for Low-Grade Glioma: A Necessary Step to Enable Patients Resuming an Active Life

Awake surgery for brain gliomas improves resection while minimizing morbidity. Although intraoperative mapping was originally used to preserve motor and language functions, the considerable increase of life expectancy, especially in low-grade glioma, resulted in the need to enhance patients’ long-term quality of life. If the main goal of awake surgery is to resume normal familial and socio-professional activities, preventing hemiparesis and aphasia is not sufficient: cognitive and emotional functions must be considered. To monitor higher-order functions, e.g., executive control, semantics or mentalizing, further tasks were implemented into the operating theater. Beyond this more accurate investigation of function-specific neural networks, a better exploration of the inter-system communication is required. Advances in brain connectomics led to a meta-network perspective of neural processing, which emphasizes the pivotal role of the dynamic interplay between functional circuits to allow complex and flexible, goal-directed behaviors. Constant multi-tasking with time constraint in awake patients may be proposed during intraoperative mapping, since it provides a mirror of the (dys)synchronization within and across neural networks and it improves the sensitivity of behavioral monitoring by increasing cognitive demand throughout the resection. Electrical mapping may hamper the patient to perform several tasks simultaneously whereas he/she is still capable to achieve each task in isolation. Unveiling the meta-network organization during awake mapping by using a more ecological multi-demand testing, more representative of the real-life conditions, constitutes a reliable way to tailor the surgical onco-functional balance based upon the expectations of each patient, enabling him/her to resume an active life with long-lasting projects.

Modern surgical management of incidental gliomas

Purpose

Gliomas are the most common primary tumors of the central nervous system and are categorized by the World Health Organization into either low-grade (grades 1 and 2) or high-grade (grades 3 and 4) gliomas. A subset of patients with glioma may experience no tumor-related symptoms and be incidentally diagnosed. These incidental low-grade gliomas (iLGG) maintain controversial treatment course despite scientific advancements. Here we highlight the recent advancements in classification, neuroimaging, and surgical management of these tumors.

Methods

A review of the literature was performed. The authors created five subtopics of focus: histological criteria, diagnostic imaging, surgical advancements, correlation of surgical resection and survival outcomes, and clinical implications.

Conclusions

Alternating studies suggest that these tumors may experience higher mutational rates than their counterparts. Significant progress in management of gliomas, regardless of the grade, has been made through modern neurosurgical treatment modalities, diagnostic neuroimaging, and a better understanding of the genetic composition of these tumors. An optimal treatment approach for patients with newly diagnosed iLGG remains ill-defined despite multiple studies arguing in favor of safe maximal resection. Our review emphasizes the not so benign nature of incidental low grade glioma and further supports the need for future studies to evaluate survival outcomes following surgical resection.

Awake Mapping With Transopercular Approach in Right Insular-Centered Low-Grade Gliomas Improves Neurological Outcomes and Return to Work

BACKGROUND

Asleep vs awake surgery for right insula-centered low-grade glioma (LGG) is still debated.

OBJECTIVE

To compare neurological outcomes and return to work after resection for right insular/paralimbic LGG performed without vs with awake mapping.

METHODS

A personal surgical experience of right insula-centered LGG was analyzed, by comparing 2 consecutive periods. In the first period (group 1), patients underwent asleep surgery with motor mapping. In the second period (group 2), patients underwent intraoperative awake mapping of movement and cognitive functions.

RESULTS

This consecutive series included 143 LGGs: 41 in group 1 (1999-2009) and 102 in group 2 (2009-2020). There were no significant difference concerning preoperative clinicoradiological characteristics and histopathology results between both groups. Intraoperative motor mapping was positive in all cases in group 1. In group 2, beyond motor mapping, somatosensory, visuospatial, language, and/or cognitive functions were identified during cortical-subcortical stimulation. Postoperatively, 3 patients experienced a long-lasting deterioration with 2 hemiparesis due to deep stroke (1.3%) and 1 severe depressive syndrome, all of them in group 1 vs none in group 2 (P = .022). The rate of RTW was 81.5% in group 1 vs 95.5% in group 2 (P = .016). The tumor volume and extent of resection did not significantly differ across both groups.

CONCLUSION

This is the first study comparing asleep vs awake surgery for right insula-centered LGG. Despite similar extent of resection, functional outcomes were significantly better in awake patients by avoiding permanent neurological impairment and by increasing RTW. These results support the mapping of higher-order functions during awake procedure.

Factors Associated With Long-term Survival in Women Who Get Pregnant After Surgery for WHO Grade II Glioma

BACKGROUND AND OBJECTIVES

Women with a WHO grade II glioma (GIIG) often question clinicians on the effects of pregnancy on their disease. Previous reports have indicated a higher risk of glioma progression during and after pregnancy. Here, the aim was to investigate post-pregnancy outcomes and predictive factors impacting overall survival in female patients who underwent GIIG surgery.

METHODS

Inclusion criteria were adult women who have been pregnant after a GIIG resection and with a stable oncological status at the time of pregnancy (no ongoing oncological treatment, no contrast enhancement, no debilitating clinical condition). Relevant cases were identified from a databank (1998-2021) of patients who underwent surgical resection for a histologically-confirmed GIIG in our department.

RESULTS

Among 345 GIIG women within their reproductive years (age<45y), 16 patients (4.6%, mean age at delivery: 30.9±5.1 years) were pregnant (twice in 5 cases). The mean interval between the last oncological treatment (surgery alone in 11 patients while followed by chemotherapy and/or radiotherapy in 5 patients) and pregnancy was 3.5 years (range 0.75-10 years). Two patients experienced seizures during pregnancy. The delivery was vaginal and uneventful in all cases but one (1 caesarean). All children had normal mental and physical development. The glioma behavior changed in 7 patients (43.7%), with an acceleration of the velocity of diameter expansion (VDE) and/or the occurrence of a contrast enhancement during or within the 3 months after pregnancy, resulting in medical treatment and/or reoperation in the early post-partum period in 7 cases. The median clinical follow-up from delivery was 5.3 years (range 1.25-11.6 years). Four other patients received delayed adjuvant therapy for glioma progression. Seven patients (43.7%) died at a median time from delivery of 3.9 years (range 1.25-5.9 years). Overall, the median survival from delivery was 5.75 years. Crucially, patients who underwent a complete surgical resection and patients with stable lesions before pregnancy lived longer (log rank, p=0.046 and p=0.0026, respectively).

CONCLUSIONS

Tumor residual volume and tumor speed growth are strong predictive factors conditioning post-pregnancy long-term survival in patients with GIIG. Identifying patients at risk is critical to provide relevant counsel to GIIG women with a desire for motherhood.

Early Surgery Prolongs Professional Activity in IDH Mutant Low-Grade Glioma Patients: A Policy Change Analysis

Background

Until 2015, Dutch guidelines recommended follow-up and biopsy rather than surgery as initial care for suspected low-grade gliomas (LGG). Given evidence that surgery could extend patient survival, our center stopped following this guideline on January 1, 2010 and opted for early maximal safe resection of LGG. The effects of early surgery on the ability of patients to work remains little documented.

Methods

A total of 104 patients operated on at our center between January 2000 and April 2013 and diagnosed with the WHO 2016 grade 2 astrocytoma, IDH mutant or oligodendroglioma, IDH mutant and deleted 1p19q were included. The clinical characteristics, survival, and work history of patients operated on before or after January 2010 were obtained from the patients' records and compared. The minimal follow-up was 8 years.

Results

As per policy change, the interval between radiological diagnosis and first surgery decreased significantly after 2010. Likewise, before 2010, 25.8% of tumors were initially biopsied, 51.6% were resected under anesthesia, and 22.5% under awake conditions versus 14.3%, 23.8%, and 61.9% after this date (p < 0.001). The severity of permanent postoperative neurological deficits decreased after 2010. In total, 82.5% of the patients returned to work postoperatively before 2010 versus 100% after 2010. The postoperative control of epilepsy increased significantly after 2010 (74.4% vs. 47.9%). The median time from diagnosis to a definitive incapacity to work increased by more than 2 years after 2010 (88.7 vs. 62.2 months).

Conclusion

A policy shift towards early aggressive surgical treatment of IDH mutant LGG is safe and prolongs the patients' ability to work.

Quality of life and return to work and sports after spinal ependymoma resection

Adult spinal ependymoma presents a rare low-grade tumor entity. Due to its incidence peak in the fourth decade of life, it mostly affects patients during a professionally and physically active time of life. We performed a retrospective monocentric study, including all patients operated upon for spinal ependymoma between 2009 and 2020. We prospectively collected data on professional reintegration, physical activities and quality-of-life parameters using EQ-5D and SF-36. Issues encountered were assessed using existing spinal-cord-specific questionnaires and free-text questions. In total, 65 of 114 patients agreed to participate. Most patients suffered from only mild pre- and postoperative impairment on the modified McCormick scale, but 67% confirmed difficulties performing physical activities in which they previously engaged due to pain, coordination problems and fear of injuries after a median follow-up of 5.4 years. We observed a shift from full- to part-time employment and patients unable to work, independently from tumor dignity, age and neurological function. Despite its benign nature and occurrence of formal only mild neurological deficits, patients described severe difficulties returning to their preoperative physical activity and profession. Clinical scores such as the McCormick grade and muscle strength may not reflect the entire self-perceived impairment appropriately.

White Matter Tracts and Diffuse Lower-Grade Gliomas: The Pivotal Role of Myelin Plasticity in the Tumor Pathogenesis, Infiltration Patterns, Functional Consequences and Therapeutic Management

For many decades, interactions between diffuse lower-grade glioma (LGG) and brain connectome were neglected. However, the neoplasm progression is intimately linked to its environment, especially the white matter (WM) tracts and their myelin status. First, while the etiopathogenesis of LGG is unclear, this tumor seems to appear during the adolescence, and it is mostly located within anterior and associative cerebral areas. Because these structures correspond to those which were myelinated later in the brain maturation process, WM myelination could play a role in the development of LGG. Second, WM fibers and the myelin characteristics also participate in LGG diffusion, since glioma cells migrate along the subcortical pathways, especially when exhibiting a demyelinated phenotype, which may result in a large invasion of the parenchyma. Third, such a migratory pattern can induce functional (neurological, cognitive and behavioral) disturbances, because myelinated WM tracts represent the main limitation of neuroplastic potential. These parameters are critical for tailoring an individualized therapeutic strategy, both (i) regarding the timing of active treatment(s) which must be proposed earlier, before a too wide glioma infiltration along the WM bundles, (ii) and regarding the anatomic extent of surgical resection and irradiation, which should take account of the subcortical connectivity. Therefore, the new science of connectomics must be integrated in LGG management, based upon an improved understanding of the interplay across glioma dissemination within WM and reactional neural networks reconfiguration, in order to optimize long-term oncological and functional outcomes. To this end, mechanisms of activity-dependent myelin plasticity should be better investigated.

Classification of Adverse Events Following Surgery in Patients With Diffuse Lower-Grade Gliomas

Background

Recently, the Therapy-Disability-Neurology (TDN) was introduced as a multidimensional reporting system to detect adverse events in neurosurgery. The aim of this study was to compare the novel TDN score with the Landriel–Ibanez classification (LIC) grade in a large cohort of patients with diffuse lower-grade glioma (dLGG). Since the TDN score lacks validation against patient-reported outcomes, we described health-related quality of life (HRQoL) change in relation to TDN scores in a subset of patients.

Methods

We screened adult patients with a surgically treated dLGG World Health Organization (WHO) grade 2 and 3 between 2010 and 2020. Up until 2017, it consists of a retrospective cohort (n = 158). From 2017 and onwards, HRQoL was registered using EuroQoL-5-dimension, three levels of response (EQ-5D 3L) questionnaire at baseline and 3 months follow-up, in a prospectively recruited cohort (n = 102). Both the LIC grade and TDN score were used to classify adverse events.

Results

In total, 231 patients were included. In 110/231 (47.6%) of the surgical procedures, a postoperative complication was registered. When comparing the TDN score to LIC grades, only a minor shift towards complications of higher order could be observed. EQ-5D 3L was reported for 45 patients. Patients with complications related to surgery had pre- to postoperative changes in EQ-5D 3L index values (n = 27; mean 0.03, 95% CI −0.06 to 0.11) that were comparable to patients without complications (n = 18; mean −0.06, 95% CI −0.21 to 0.08). In contrast, patients with new-onset neurological deficit had a deterioration in HRQoL at follow-up, with a mean change in the EQ-5D 3L index value of 0.11 (n = 13, 95% CI 0.0 to 0.22) compared to −0.06 (n = 32, 95% CI −0.15 to 0.03) for all other patients.

Conclusions

In patients with dLGG, TDN scores compared to the standard LIC tend to capture more adverse events of higher order. There was no clear relation between TDN severity and HRQoL. However, new-onset neurological deficit caused impairment in HRQoL. For the TDN score to better align with patient-reported outcomes, more emphasis on neurological deficit and function should be considered.

Quality of life following awake surgery depends on ability of executive function, verbal fluency, and movement

INTRODUCTION

The outcome of awake surgery has been evaluated based on functional factors, return to work, and oncological aspects, and there have been no reports directly examining QOL. This study aimed to investigate the outcome of QOL following awake surgery and to determine the functional factors influencing QOL.

METHODS

Seventy patients with WHO grade II/III gliomas were included. For the assessment of QOL, we used the SF-36 and calculated summary and sub-component scores. Three summary component scores, including physical (PCS), mental (MCS), and role/social summary (RCS) component scores, were computed based on sub-component scores. Additionally, various assessments of neurological/neuropsychological function were performed. We performed univariate and multiple regression analyses to investigate the functional factors influencing the SF-36.

RESULTS

PCS and MCS were maintained, but only RCS was low to 42.0 ± 16.1. We then focused on the RCS and its sub-components: general health (GH), role physical (RP), social functioning (SF), and role emotional (RE). Multiple regression analysis showed following significant correlations between the sub-component scores and brain functions: GH to executive function and movement (p = 0.0033 and 0.032), RP to verbal fluency and movement (p = 0.0057 and 0.0010), and RE to verbal fluency (p = 0.020). Furthermore, when the sub-component scores were compared between groups with and without functional deficits related to GH, RP, and RE, each score was significantly lower in the groups with functional deficits (p = 0.012, 0.014, and 0.0049, respectively).

CONCLUSIONS

In patients who underwent awake surgery, a subset of patients had low QOL because of poor RCS. Functional factors influencing QOL included executive function, verbal fluency, and movement.

The death of localizationism: The concepts of functional connectome and neuroplasticity deciphered by awake mapping, and their implications for best care of brain-damaged patients

Although clinical neurology was mainly erected on the dogma of localizationism, numerous reports have described functional recovery after lesions involving presumed non-compensable areas in an inflexible view of brain processing. Here, the purpose is to review new insights into the functional connectome and the mechanisms underpinning neural plasticity, gained from intraoperative direct electrostimulation mapping and real-time behavioral monitoring in awake patients, combined with perioperative neuropsychological and neuroimaging data. Such longitudinal anatomo-functional correlations resulted in the reappraisal of classical models of cognition, especially by highlighting the dynamic interplay within and between neural circuits, leading to the concept of meta-network (network of networks), as well as by emphasizing that subcortical connectivity is the main limitation of neuroplastic potential. Beyond their contribution to basic neurosciences, these findings might also be helpful for an optimization of care for brain-damaged patients, such as in resective oncological or epilepsy neurosurgery in structures traditionally deemed inoperable (e.g., in Broca's area) as well as for elaborating new programs of functional rehabilitation, eventually combined with transcranial brain stimulation, aiming to change the connectivity patterns in order to enhance cognitive competences following cerebral injury.

Dynamic Interplay between Lower-Grade Glioma Instability and Brain Metaplasticity: Proposal of an Original Model to Guide the Therapeutic Strategy

The behavior of lower-grade glioma (LGG) is changing over time, spontaneously, and in reaction to treatments. First, due to genomic instability and clonal expansion, although LGG progresses slowly during the early period of the disease, its growth velocity will accelerate when this tumor will transform to a higher grade of malignancy. Furthermore, its pattern of progression may change following therapy, e.g., by switching from a proliferative towards a more diffuse profile, in particular after surgical resection. In parallel to this plasticity of the neoplasm, the brain itself is constantly adapting to the tumor and possible treatment(s) thanks to reconfiguration within and between neural networks. Furthermore, the pattern of reallocation can also change, especially by switching from a perilesional to a contrahemispheric functional reorganization. Such a reorientation of mechanisms of cerebral reshaping, related to metaplasticity, consists of optimizing the efficiency of neural delocalization in order to allow functional compensation by adapting over time the profile of circuits redistribution to the behavioral modifications of the glioma. This interplay between LGG mutations and reactional connectomal instability leads to perpetual modulations in the glioma-neural equilibrium, both at ultrastructural and macroscopic levels, explaining the possible preservation of quality of life despite tumor progression. Here, an original model of these dynamic interactions across LGG plasticity and the brain metanetwork is proposed to guide a tailored step-by-step individualized therapeutic strategy over years. Integration of these new parameters, not yet considered in the current guidelines, might improve management of LGG patients.

Extending the multistage surgical strategy for recurrent initially low-grade gliomas: functional and oncological outcomes in 31 consecutive patients who underwent a third resection under awake mapping

OBJECTIVE

Maximal safe resection is the first treatment in diffuse low-grade glioma (DLGG). Due to frequent tumor recurrence, a second surgery has already been reported, with favorable results. This study assesses the feasibility and functional and oncological outcomes of a third surgery in recurrent DLGG.

METHODS

Patients with DLGG who underwent a third functional-based resection using awake mapping were consecutively selected. They were classified into group 1 in cases of slow tumor regrowth or group 2 if a radiological enhancement occurred during follow-up. All data regarding clinicoradiological features, histomolecular results, oncological treatment, and survival were collected.

RESULTS

Thirty-one patients were included, with a median age of 32 years. There were 20 astrocytomas and 11 oligodendrogliomas in these patients. Twenty-one patients had medical oncological treatment before the third surgery, consisting of chemotherapy in 19 cases and radiotherapy in 8 cases. No neurological deficit persisted after the third resection except mild missing words in 1 patient, with 84.6% of the patients returning to work. The median follow-up duration was 13.1 ± 3.4 years since diagnosis, and 3.1 ± 2.9 years since the third surgery. The survival rates at 7 and 10 years were 100% and 89.7%, respectively, with an estimated median overall survival of 17.8 years since diagnosis. A comparison between the groups showed that the Karnofsky Performance Scale score dropped below 80 earlier in group 2 (14.3 vs 17.1 years, p = 0.01). Median residual tumor volume at the third surgery was smaller (2.8 vs 14.4 cm3, p = 0.003) with a greater extent of resection (89% vs 70%, p = 0.003) in group 1.

CONCLUSIONS

This is the first consecutive series showing evidence that, in select patients with progressive DLGG, a third functional-based surgery can be achieved using awake mapping with low neurological risk and a high rate of total resection, especially when reoperation is performed before malignant transformation.

The benefit of early surgery on overall survival in incidental low grade glioma patients: a multicenter study

BACKGROUND

The role of surgery for incidentally discovered diffuse low-grade gliomas (iLGGs) is debatable and poorly documented in current literature.

OBJECTIVE

The aim was to identify factors that influence survival for patients that underwent surgical resection of iLGGs in a large multicenter population.

METHODS

Clinical, radiological, and surgical data were retrospectively analyzed in 267 patients operated for iLGG from 4 neurosurgical Centers. Univariate and multivariate analyses were performed to identify predictors of overall survival (OS) and tumor recurrence (TR).

RESULTS

The OS rate was 92.41%. The 5- and 10-year estimated OS rates were 98.09% and 93.2% respectively. OS was significantly longer for patients with a lower preoperative tumor volume (p=0.001) and higher extent of resection (EOR) (p=0.037), regardless the WHO defined molecular class (p=0.2). In the final model, OS was influenced only by the preoperative tumor volume (p=0.006), while TR by early surgery (p=0.028). A negative association was found between preoperative tumor volumes and EOR (rs = -0.44, p<0.001).The median preoperative tumor volume was 15 cm 3. The median EOR was 95%. Total or supratotal resection of FLAIR abnormality was achieved in 61.62% of cases.Second surgery was performed in 26.22%. The median time between surgeries was 5.5 years. Histological evolution to high grade glioma was detected in 22.85% of cases (16/70). Permanent mild deficits were observed in 3.08% of cases.

CONCLUSIONS

This multicenter study confirms the results of previous studies investigating surgical management of iLGGs and thereby strengthens the evidence in favour of early surgery for these lesions.

Neuropsychological assessments before and after awake surgery for incidental low-grade gliomas

OBJECTIVE

Early surgery in presumed asymptomatic patients with incidental low-grade glioma (ILGG) has been suggested to improve maximal resection rates and overall survival. However, no study has reported on the impact of such preventive treatment on cognitive functioning. The aim of this study was to investigate neuropsychological outcomes in patients with ILGG who underwent preventive surgery.

METHODS

This was a retrospective analysis of a consecutive series of patients with ILGG who underwent awake surgery and who had presurgical and 3-month postsurgical neuropsychological assessments. Data were normalized into z-scores and regrouped by cognitive domains. Clinicoradiological data, histomolecular profile, and differences in z-scores (Δz-scores) were analyzed.

RESULTS

Forty-seven patients were included (mean age 39.2 ± 11.3 years). Twenty-eight patients (59.6%) underwent supratotal or total resections. All patients were still alive after a mean follow-up of 33.0 ± 30.8 months. Forty-one patients (87.2%) had stable (n = 34, 72.3%) or improved (Δz-score > 1; n = 7, 14.9%) neurocognitive outcomes after surgery. Six patients (12.8%) presented a slight impairment (Δz-score < -1) in at least one cognitive domain. The mean presurgical and postsurgical z-scores were comparable except in the psychomotor speed and attention domain. A significant correlation between presurgical executive functioning and tumor volume was reported, whereas the extent of resection and histomolecular profile did not impact neuropsychological outcomes.

CONCLUSIONS

Early surgical treatment in presumed asymptomatic patients with ILGG was associated with stable or improved neuropsychological outcomes in 87.2% of patients at 3 months, with only mild cognitive decline observed in 6 patients. In return, supratotal or total resections were achieved in most patients, and all patients were still alive at the end of the follow-up.

Presence of a translator in the operating theater for awake mapping in foreign patients with low-grade glioma: a surgical experience based on 18 different native languages

OBJECTIVE

Intraoperative brain mapping with neurocognitive monitoring during awake surgery is currently the standard pattern of care for patients with diffuse low-grade glioma (DLGG), allowing a maximization of the extent of resection (EOR) while preserving quality of life. This study evaluated the feasibility of DLGG resections performed with intraoperative cognitive monitoring via the assistance of a translator for patients speaking foreign languages, and compared the surgical functional and oncological outcomes according to the possibility of direct communication with the surgical team.

METHODS

Foreign patients who underwent awake surgery with intraoperative electrical mapping with the assistance of a translator for the resection of a DLGG in the authors' institution between January 2010 and December 2020 were included. Patients whose native language included one of the three languages spoken by the surgical team (i.e., French, English, or Spanish) were excluded. The patients were classified into two groups. Group 1 was composed of patients able to communicate in at least one of these three languages in addition to their own native language. Group 2 was composed of patients who spoke none of these languages, and therefore were unable to communicate directly with the operating staff. The primary outcome was the patients' ability to return to work 3 months after surgery.

RESULTS

Eighty-four patients were included, of whom 63 were classified in group 1 and 21 in group 2. Eighteen different native languages were tested in the operating theater. Awake mapping was successful, with elicitation of transitory disturbances in all patients. There was no significant difference in the 3-month return-to-work status between the two groups (95% in group 1 [n = 58/61] vs 88% in group 2 [n = 15/17]; p = 0.298). Similarly, no significant difference between the two groups was found regarding the intraoperative tasks performed, the mean duration of the surgery, and the rate of permanent postoperative deficit. A significantly greater EOR was observed in group 1 patients in comparison to group 2 patients (90.4% ± 10.6% vs 87.7% ± 6.1%; p = 0.029).

CONCLUSIONS

Real-time translation by an interpreter during awake resection of glioma is feasible and safe in foreign patients. Nonetheless, when no direct verbal communication is possible between the surgical team and the patient, the EOR is less.

Extent of resection in diffuse low-grade gliomas and the role of tumor molecular signature-a systematic review of the literature

There is a lack of class I evidence concerning the impact of surgery in the treatment of diffuse low-grade glioma; the early maximal resection with preservation of eloquent brain areas has been accepted as the first therapeutic option. We performed a systematic review of the literature using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and protocol. Inclusion criteria: only case series with at least 100 patients containing supratentorial hemispheric diffuse low-grade glioma (according to any of the WHO classification used in papers published between 2000 to 2019), with pre- and postoperative MRI study were included in the qualitative and quantitative analyses. The extent of resection should be defined based on MRI at least in two categories and correlated with patients' outcomes (with univariate or multivariate analyses) using overall survival (OS) or malignant progression-free survival (MPFS). A total of 18 series with 4386 patients, published in 20 papers, were included in this systematic review. All the series that evaluates the relation between the extent of resection (EOR) and OS showed a statistically significant improvement of OS at univariate and/or multivariate analyzes with a greater EOR. Six studies showed a statistically significant improvement of MPFS with a greater EOR. We demonstrate that when a more rigorous analysis of EOR is performed, a benefit of a more aggressive resection on OS and MPFS is observed. Our review about EOR in different molecular groups of DLGG also suggests a benefit of maximum safe resection for all different subtypes, even though "radical surgery" may be associated with better OS and MPFS in tumors with a more aggressive signature.

Functional Outcomes and Health-Related Quality of Life Following Glioma Surgery

Functional outcome following glioma surgery is defined as how the patient functions or feels. Functional outcome is a coprimary end point of surgery in patients with diffuse glioma, together with oncological outcome. In this review, we structure the functional outcome measurements following glioma surgery as reported in the last 5 yr. We review various perspectives on functional outcome of glioma surgery with available measures, and offer suggestions for their use. From the recent neurosurgical literature, 160 publications were retrieved fulfilling the selection criteria. In these publications, neurological outcomes were reported most often, followed by activities of daily living, seizure outcomes, neurocognitive outcomes, and health-related quality of life or well-being. In more than a quarter of these publications functional outcome was not reported. A minimum essential consensus set of functional outcome measurements would benefit comparison across neurosurgical reports. The consensus set should be based on a combination of clinician- and patient-reported outcomes, assessed at a predefined time before and after surgery. The selected measurements should have psychometric properties supporting the intended use including validity-related evidence, reliability, and sensitivity to detect meaningful change with minimal burden to ensure compliance. We circulate a short survey as a start towards reporting guidelines. Many questions remain to better understand, report, and improve functional outcome following glioma surgery.

Predictive Evolution Factors of Incidentally Discovered Suspected Low-Grade Gliomas: Results From a Consecutive Series of 101 Patients

BACKGROUND

Incidentally discovered suspected diffuse low-grade gliomas (LGGs) on brain imaging pose a challenge to neurosurgeons. Modern surgical series of LGGs favor early prophylactic surgery with a maximal extent of resection. However, some nonevolutive lesions may mimic LGGs on magnetic resonance imaging (MRI).

OBJECTIVE

To determine objective criteria to advocate surgical resection of an incidentally discovered suspected LGG based upon MRI findings.

METHODS

The prospective cohort of patients referred to our institution for an incidental finding suggestive of LGG was retrospectively reviewed. Stable lesions underwent systematic serial MRI follow-up, while evolutive lesions underwent prophylactic surgery under awake conditions. Initial clinico-radiological features were compared between stable and evolutive lesions in order to determine predictive criteria of further evolution.

RESULTS

Among 101 patients referred for surgical resection of incidentally discovered suspected LGG in our center, 19 patients (18.8%) had nonevolutive MRI lesions after a mean follow-up of 46.9 ± 34.9 mo. Insular topography (P = .003), higher mean volume at discovery (19.2 vs 5.2 cm3, P < .001), and adjacent sulcal effacement (P = .001) were associated with evolutive lesions. Histopathological diagnosis of LGG was confirmed in all surgical cases.

CONCLUSION

Increasing volume is an effective predictor of LGG diagnosis in incidental MRI findings, as all patients who subsequently underwent surgery had confirmed histopathological diagnosis of diffuse glioma. Approximately 18.8% of incidental findings were stable over time. Insular topography, adjacent sulcal effacement, and volume greater than 4.5 cm3 were predictive of further radiological progression. These significant elements will help neurosurgeons to define personalized strategies in this complex setting of incidental discovery.

Disrupting self-evaluative processing with electrostimulation mapping during awake brain surgery

Brain awake surgery with cognitive monitoring for tumor removal has become a standard of treatment for functional purpose. Yet, little attention has been given to patients' interpretation and awareness of their own responses to selected cognitive tasks during direct electrostimulation (DES). We aim to report disruptions of self-evaluative processing evoked by DES during awake surgery. We further investigate cortico-subcortical structures involved in self-assessment process and report the use of an intraoperative self-assessment tool, the self-confidence index (SCI). Seventy-two patients who had undergone awake brain tumor resections were selected. Inclusion criteria were the occurrence of a DES-induced disruption of an ongoing task followed by patient's failure to remember or criticize these impairments, or a dissociation between patient's responses to an ongoing task and patient's SCI. Disruptions of self-evaluation were frequently associated with semantic disorders and critical sites were mostly found along the left/right ventral semantic streams. Disconnectome analyses generated from a tractography-based atlas confirmed the high probability of the inferior fronto-occipital fasciculus to be transitory 'disconnected'. These findings suggest that white matters pathways belonging to the ventral semantic stream may be critically involved in human self-evaluative processing. Finally, the authors discuss the implementation of the SCI task during multimodal intraoperative monitoring.

Brain connectomics applied to oncological neuroscience: from a traditional surgical strategy focusing on glioma topography to a meta-network approach

The classical way for surgical selection and planning in cerebral glioma mainly focused on tumor topography. The emerging science of connectomics, which aims of mapping brain connectivity, resulted in a paradigmatic shift from a modular account of cerebral organization to a meta-network perspective. Adaptive behavior is actually mediated by constant changes in interactions within and across large-scale delocalized neural systems underlying conation, cognition, and emotion. Here, to optimize the onco-functional balance of glioma surgery, the purpose is to switch toward a connectome-based resection taking account of both relationships between the tumor and critical distributed circuits (especially subcortical pathways) as well as the perpetual instability of the meta-network. Such dynamic in the neural spatiotemporal integration permits functional reallocation leading to neurological recovery after massive resection in structures traditionally thought as "inoperable." This better understanding of connectome increases benefit/risk ratio of surgery (i) by selecting resection in areas deemed "eloquent" according to a localizationist dogma; (ii), conversely, by refining intraoperative awake cognitive mapping and monitoring in so-called non-eloquent areas; (iii) by improving preoperative information, enabling an optimal selection of intrasurgical tasks tailored to the patient's wishes; (iv) by developing an "oncological disconnection surgery"; (v) by defining a personalized multistep surgical strategy adapted to individual brain reshaping potential; and (vi) ultimately by preserving environmentally and socially appropriate behavior, including return to work, while increasing the extent of (possibly repeated) resection(s). Such a holistic vision of neural processing can enhance reliability of connectomal surgery in oncological neuroscience and may also be applied to restorative neurosurgery.

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.

Characteristics of Patients Returning to Work After Brain Tumor Surgery

Objective: To investigate the differences between patients returning to work and those who did not after brain tumor surgery.

Methods: Patients were evaluated before surgery and after 3 months. The Montreal Cognitive Assessment test, Trail-Making Test (parts A and B), 15-word Rey–Osterrieth Word List (immediate and delayed recall), F-A-S tests, and Karnosfky Performance Status were used to assess cognitive status, attention, executive functions, memory, word fluency, and functional status. Patient-reported outcome measures (PROMs) used to evaluate emotional distress and disability were the Hospital Anxiety and Depression Scale and World Health Organization Disability Assessment Schedule. Clinical and work-related variables, PROMs, and cognitive tests were compared using chi-squared, t-test or Mann–Whitney U test.

Results: Sixty patients were included. Patients returning to work were 61.3 and 31.0% among people with meningioma and glioma, respectively. They reported lower postoperative disability and lesser home-to-work travel time. Patients with meningioma also showed better preoperative and postoperative attention and executive functions, better postoperative functional and cognitive status, and lower frequency of treatments.

Conclusions: These variables should be considered in a clinical context to plan interventions for people who need support during return to work and in future research to investigate preoperative and postoperative predictive factors of going back to work.