Survival, prognostic factors, and therapeutic efficacy in low-grade glioma: a retrospective study in 379 patients

Neuropsychological longitudinal study of patients with low-grade gliomas: Cognitive impairment

This study is part of a longitudinal research program, in which patients diagnosed with low-grade gliomas (LGG: n = 13), as well as healthy controls (n = 13), were consecutively recruited and neuropsychologically followed for 7 years. The patients are followed up regardless of variations in treatment. A composite score is used (Global Deficit Score: GDS) included cognitive measures where at least five patients had a negative change: information processing speed, speed of naming, construction ability, verbal fluency, non-verbal thinking, and immediate non-verbal memory. The most important finding in this 7-year follow-up study is that two-thirds of the patients developed cognitive impairment. The remaining third of the patients showed stability in their cognitive ability and were still alive 17 years after diagnosis. Younger patients with tumors in the right frontal or posterior regions showed a more favorable development. Patients with frontal tumors and a declined GDS show also significant changes in executive functions. Given the limited number, no firm conclusions can be drawn regarding the impact of tumor localization. The impact of LGG on cognition and the survival time after diagnosis varies considerably between patients. However, most of the patients (69%) showed cognitive impairment during the seven years we followed them.

An analysis of prognostic factors in a cohort of low-grade gliomas and degree of consistency between RTOG and EORTC scores

Due to their rarity and heterogeneity and despite the introduction of molecular features in the current WHO classification, clinical criteria such as those from the European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) are still being used to make treatment decisions in low-grade gliomas (LGG). Patients with diffuse low-grade glioma treated at our institution between 2002 and 2018 were analyzed, retrieving and assessing the degree of consistency between the EORTC and RTOG criteria, as well as the isocitrate dehydrogenase 1 and 2 (IDH) gene mutational status. Likewise, multivariate analyses were performed to ascertain the superiority of any of the factors over the others. One hundred and two patients were included. The degree of consistency between the RTOG and EORTC criteria was 71.6% (K = 0.426; p = 0.0001). Notably, 51.7% of those assigned to low risk by the EORTC were classified as high risk according to the RTOG classification. In multivariate analysis, only complete resection, age > 40 years, size and IDH mutation status were independently correlated with OS. When the RTOG and EORTC scores were entered into the model, only the EORTC model was independently associated with mortality. The degree of consistency between the EORT and RTOG criteria is low. Therefore, there is a need to integrate clinical-molecular scores to improve treatment decisions in LGG.

Targeted metabolomics analyses for brain tumor margin assessment during surgery

MOTIVATION

Identification and removal of micro-scale residual tumor tissue during brain tumor surgery are key for survival in glioma patients. For this goal, High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) spectroscopy-based assessment of tumor margins during surgery has been an effective method. However, the time required for metabolite quantification and the need for human experts such as a pathologist to be present during surgery are major bottlenecks of this technique. While machine learning techniques that analyze the NMR spectrum in an untargeted manner (i.e. using the full raw signal) have been shown to effectively automate this feedback mechanism, high dimensional and noisy structure of the NMR signal limits the attained performance.

RESULTS

In this study, we show that identifying informative regions in the HRMAS NMR spectrum and using them for tumor margin assessment improves the prediction power. We use the spectra normalized with the ERETIC (electronic reference to access in vivo concentrations) method which uses an external reference signal to calibrate the HRMAS NMR spectrum. We train models to predict quantities of metabolites from annotated regions of this spectrum. Using these predictions for tumor margin assessment provides performance improvements up to 4.6% the Area Under the ROC Curve (AUC-ROC) and 2.8% the Area Under the Precision-Recall Curve (AUC-PR). We validate the importance of various tumor biomarkers and identify a novel region between 7.97 ppm and 8.09 ppm as a new candidate for a glioma biomarker.

AVAILABILITY AND IMPLEMENTATION

The code is released at https://github.com/ciceklab/targeted_brain_tumor_margin_assessment. The data underlying this article are available in Zenodo, at https://doi.org/10.5281/zenodo.5781769.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Prognostic Factors Associated With Survival in Patients With Diffuse Astrocytoma

Background: Diffuse astrocytoma (DA) is a rare disease with inadequately understood epidemiological characteristics and prognosis. Identification of the factors associated with the survival in DA patients is therefore necessary. In this study, we aim to investigate the clinicopathological characteristics of DA to delineate factors influencing the survival of DA. Methods: A population-based cohort study was conducted, utilizing prospectively extracted data from the Surveillance, Epidemiology and End Results (SEER) database. Patients with histological diagnosis of DA in the SEER database from 1973 to 2017 were included. Results: A total of 799 participants with DA were included, consisting of 95.9% fibrillary astrocytoma and 4.1% protoplasmic variants. The average age of participants was 41.9 years, with 57.2% being male. The majority of the population was white (87.5%). More than half (53.9%) of the patients were married. DA arose mostly in the cerebrum (63.8%). Around 71.6% of the population had received surgical treatment. The overall 1-, 3-, 5-, and 10-year survival rate were 73.7, 55.2, 49.4, and 37.6%, respectively. Kaplan-Meier analysis showed that age at diagnosis, marital status, primary tumor site, tumor size, and surgery was possibly associated with cancer-specific survival (CSS) (p < 0.05). Multivariate Cox proportional hazard analysis indicated that surgery was a protective factor whereas older age, larger tumor size, and tumor in the brainstem were harmful factors for patients with DA. Moreover, a nomogram predicting 5- and 10-year survival probability for DA was developed. Conclusions: Age, primary tumor site, tumor size, and surgery were associated with the survival of patients with DA.

Midline Astrocytic Tumors in Children: A Retrospective Study of 152 Cases

The aim of this study was to analyze the various midline structures having preponderance for astrocytoma, their incidence, clinical features, operative approach, prognosis, and outcomes in children. It is a retrospective analysis of 152 cases with midline astrocytic tumors in children admitted between January 1995 and December 2012 in the Department of Neurosurgery at Sanjay Gandhi Postgraduate Institute of Medical sciences Lucknow, India. The mean age of the cases with midline astrocytic tumors was 9.29 ± 4.56 years. Majority of these tumors occurred in the age group of 6 to 10 years (n = 58, 38.16%), with male to female ratio being 1.66:1. Out of 152 cases, tumors located at midline cerebellum constituted majority of the cases (n = 38, 25%) followed by brain stem (n = 28, 18.42%), thalamic region (n = 24, 15.79%), corpus callosum (n = 18, 11.82%), pineal region (n = 12, 7.89%), optic nerve (n = 12, 7.89%), chiasmo-hypothalamic (n = 10, 6.58%), and septum pellucidum astrocytomas (n = 10, 6.58%). Majority of these tumors were of low-grade type (n = 136, 89.47%), and pilocytic astrocytomas were the commonest subtypes. Out of 152 cases, 136 (89.47%) cases had improved outcomes, 8 (5.26%) remained as they were in preoperative state, and mortality was seen in 8 (5.26%) of the cases at 3 to 77 months (mean 26.70 ± 9.70) of follow-up. Midline structures having preponderance for astrocytomas were midline cerebellum, brain stem, thalamus, corpus callosum, pineal region, optic nerve, chiasmo-hypothalamic, and septum pellucidum. Cerebellum was the commonest site. Most of these astrocytomas were of low grade with pilocytic astrocytoma being the commonest subtype. With meticulous presurgical planning, most of these tumors have good outcome with significant reduction in mortality and morbidity.

Toxicity Profile of Procarbazine Lomustine and Vincristine Chemotherapy in Low-Grade Glioma - Retrospective Review

Background

The role of Procarbazine Lomustine and Vincristine (PCV) chemotherapy is already established in terms of improving survival in low-grade glioma (LGG). This improved survival has led to the increasing administration of PCV to LGG patients over the past years. However, like other chemotherapies, serious hematological and non-hematological toxicities may occur. The purpose of this study was to evaluate the toxicity profile of PCV and its clinical relevance in our practice. 

Materials and Methods

We reviewed 63 patients of LGG retrospectively who received chemotherapy PCV between January 2015 and January 2018 at Shaukat Khanum Memorial Cancer Hospital & Research Centre, Lahore.

Results

Significant hematological toxicity as grade 3 anemia, thrombocytopenia, and neutropenia occurred in 19%, 27%, and 46% respectively with PCV. Other toxicities such as neurotoxicity, vomiting and derangement of liver enzymes occurred in 3.2%, 19%, and 19% respectively. Patients who were on concurrent anticonvulsants had no increase in PCV toxicity. Survival was not impacted by hematological toxicities up to grade 3.

Conclusion

PCV chemotherapy is associated with major hematological, hepatic, and clinical toxicities (vomiting, constipation, and neuropathy). Hematological toxicities influenced the course of treatment in terms of delays and interruptions.

A Case of Diffuse Astrocytoma with 32-year Survival after Boron Neutron Capture Therapy

A 39-year-old man had received boron neutron capture therapy (BNCT) for a grade II astrocytoma (compatible with diffuse astrocytoma, not otherwise specified in the WHO 2016 criteria). He returned to his previous work after surgery, but, 7 years later, he suddenly developed seizures, and his health condition deteriorated. Therefore, he underwent a second surgery. The mass removed in the second operation was mostly necrotic as a result of previous radiation treatment. He then showed no signs of recurrence and did not require any treatment other than antiepileptic drugs for 25 years. He was able to be employed by a listed company until the age of 65 years for light jobs as a physically handicapped individual. This case suggests the effectiveness of BNCT even for rather low-grade astrocytomas.

The Prognostic Value of MRI Subventricular Zone Involvement and Tumor Genetics in Lower Grade Gliomas

BACKGROUND AND PURPOSE

Glioblastomas (GBMs) that involve the subventricular zone (SVZ) have a poor prognosis, possibly due to recruitment of neural stem cells. The purpose of this study was to evaluate whether SVZ involvement by lower grade gliomas (LGG), WHO grade II and III, similarly predicts poorer outcomes. We further assessed whether tumor genetics and cellularity are associated with SVZ involvement and outcomes.

METHODS

Forty-five consecutive LGG patients with preoperative imaging and next generation sequencing were included in this study. Regional SVZ involvement and whole tumor apparent diffusion coefficient (ADC) values, as a measure of cellularity, were assessed on magnetic resonance imaging. Progression was determined by RANO criteria. Kaplan-Meier curves and Cox regression analyses were used to determine the hazard ratios (HR) for progression and survival.

RESULTS

Frontal, parietal, temporal, and overall SVZ involvement and ADC values were not associated with progression or survival (P ≥ .05). However, occipital SVZ involvement, seen in two patients, was associated with a higher risk of tumor progression (HR = 6.6, P = .016) and death (HR = 31.5, P = .015), CDKN2A/B mutations (P = .03), and lower ADC histogram values at the 5th (P = .026) and 10th percentiles (P = .046). Isocitrate dehydrogenase, phosphatase and tensin homolog, epidermal growth factor receptor, and cyclin-dependent kinase 4 mutations were also prognostic (P ≤ .05).

CONCLUSIONS

Unlike in GBM, overall SVZ involvement was not found to strongly predict poor prognosis in LGGs. However, occipital SVZ involvement, though uncommon, was prognostic and found to be associated with CDKN2A/B mutations and tumor hypercellularity. Further investigation into these molecular mechanisms underlying occipital SVZ involvement in larger cohorts is warranted.

Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

BACKGROUND

This is an update of the review originally published in 2011 and first updated in 2015. In most people with low-grade gliomas (LGG), the primary treatment regimen remains a combination of surgery followed by postoperative radiotherapy. However, the optimal timing of radiotherapy is controversial. It is unclear whether to use radiotherapy in the early postoperative period, or whether radiotherapy should be delayed until tumour progression occurs.

OBJECTIVES

To assess the effects of early postoperative radiotherapy versus radiotherapy delayed until tumour progression for low-grade intracranial gliomas in people who had initial biopsy or surgical resection.

SEARCH METHODS

Original searches were run up to September 2014. An updated literature search from September 2014 through November 2019 was performed on the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), MEDLINE via Ovid (September 2014 to November week 2 2019), and Embase via Ovid (September 2014 to 2019 week 46) to identify trials for inclusion in this Cochrane review update.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared early versus delayed radiotherapy following biopsy or surgical resection for the treatment of people with newly diagnosed intracranial LGG (astrocytoma, oligodendroglioma, mixed oligoastrocytoma, astroblastoma, xanthoastrocytoma, or ganglioglioma). Radiotherapy may include conformal external beam radiotherapy (EBRT) with linear accelerator or cobalt-60 sources, intensity-modulated radiotherapy (IMRT), or stereotactic radiosurgery (SRS).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed the trials for inclusion and risk of bias, and extracted study data. We resolved any differences between review authors by discussion. Adverse effects were also extracted from the study report. We performed meta-analyses using a random-effects model with inverse variance weighting.

MAIN RESULTS

We included one large, multi-institutional, prospective RCT, involving 311 participants; the risk of bias in this study was unclear. This study found that early postoperative radiotherapy was associated with an increase in time to progression compared to observation (and delayed radiotherapy upon disease progression) for people with LGG but did not significantly improve overall survival (OS). The median progression-free survival (PFS) was 5.3 years in the early radiotherapy group and 3.4 years in the delayed radiotherapy group (hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.45 to 0.77; P < 0.0001; 311 participants; 1 trial; low-quality evidence). The median OS in the early radiotherapy group was 7.4 years, while the delayed radiotherapy group experienced a median overall survival of 7.2 years (HR 0.97, 95% CI 0.71 to 1.33; P = 0.872; 311 participants; 1 trial; low-quality evidence). The total dose of radiotherapy given was 54 Gy; five fractions of 1.8 Gy per week were given for six weeks. Adverse effects following radiotherapy consisted of skin reactions, otitis media, mild headache, nausea, and vomiting. Rescue therapy was provided to 65% of the participants randomised to delayed radiotherapy. People in both cohorts who were free from tumour progression showed no differences in cognitive deficit, focal deficit, performance status, and headache after one year. However, participants randomised to the early radiotherapy group experienced significantly fewer seizures than participants in the delayed postoperative radiotherapy group at one year (25% versus 41%, P = 0.0329, respectively).

AUTHORS' CONCLUSIONS

Given the high risk of bias in the included study, the results of this analysis must be interpreted with caution. Early radiation therapy was associated with the following adverse effects: skin reactions, otitis media, mild headache, nausea, and vomiting. People with LGG who underwent early radiotherapy showed an increase in time to progression compared with people who were observed and had radiotherapy at the time of progression. There was no significant difference in overall survival between people who had early versus delayed radiotherapy; however, this finding may be due to the effectiveness of rescue therapy with radiation in the control arm. People who underwent early radiation had better seizure control at one year than people who underwent delayed radiation. There were no cases of radiation-induced malignant transformation of LGG. However, it remained unclear whether there were differences in memory, executive function, cognitive function, or quality of life between the two groups since these measures were not evaluated.

Isocitrate Dehydrogenase Mutations in Low-Grade Gliomas Correlate With Prolonged Overall Survival in Older Patients

BACKGROUND

Older age has been associated with worse outcomes in low-grade gliomas (LGGs). Given their rarity in the older population, determining optimal treatment plans and patient outcomes remains difficult.

OBJECTIVE

To retrospectively study LGG survival outcomes in an older population stratified by molecular genetic profiles.

METHODS

We included patients age ≥40 yr with pathologically confirmed World Health Organization grade II gliomas treated at a single institution between 1995 and 2015. We collected tumor genomic information when available.

RESULTS

Median overall survival for the entire group (n = 111, median age 51 yr, range 40-77 yr) was 15.75 yr with 5- and 10-yr survival rates of 84.3% and 67.7%, respectively. On univariate analysis, patients with isocitrate dehydrogenase (IDH) mutation had significantly increased survival compared to IDH wildtype (hazard ratio [HR] 0.17 [0.07-0.45], P < .001). Older age, seizure at presentation, larger tumor size, IDH wildtype, biopsy only, chemotherapy, and radiation were significantly associated with shorter survival based on univariate analyses. In patients with known IDH status (n = 73), bivariate analysis of IDH mutation status and age showed only IDH status significantly influenced overall survival (HR 0.22 [0.07-0.68], P = .008). Greater surgical resection was predictive of survival, although extent of resection significantly correlated with IDH mutation status (odds ratio 7.5; P < .001).

CONCLUSION

We show that genomic alterations in LGG patients ≥40 occur at high rates like the younger population and predict a similar survival advantage. Maximizing surgical resection may have survival benefit, although feasibility of resection is often linked to IDH status. Given the importance of molecular genetics, a redefinition of prognostic factors associated with these tumors is likely to emerge.

Butterfly Tumor of the Corpus Callosum: Clinical Characteristics, Diagnosis, and Survival Analysis

Background:

The pathologies implicate the bilateral corpus callosum that builds the butterfly pattern on axial view. These tumors have seldom been investigated for both clinical manifestations and outcome.

Objective:

The objective of this study was to describe the clinical characteristics and outcomes of the butterfly tumor and to identify the predictive factors associated with survival outcome.

Methods:

A retrospective study of 50 butterfly tumor was conducted between 2003 and 2016. The clinical characteristics, imaging, and outcome were assessed for the purpose of descriptive analysis. Using the Kaplan–Meier method, the median overall survival of the butterfly tumor was determined. Furthermore, the Cox proportional hazard regression was the estimated hazard ratio for death.

Results:

Diffuse large B-cell lymphoma was common of butterfly lesions. The mortality rate was 78% and overall median survival time was 16.03 months (95% confidence interval: 14.0–19.8). Using Cox proportional hazards regression, the independent prognostic factors were Karnofsky Performance Status score ≤70, splenium involvement, and butterfly glioblastoma.

Conclusions:

The butterfly tumor is a poor prognostic disease compared with each histology subgroup. Further molecular investigation is preferable to explore genetic variations associated with these tumors.

Concordance between RTOG and EORTC prognostic criteria in low-grade gliomas

Aim: European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) criteria are used to choose treatment in low-grade gliomas. However, no data exist on their concordance. Methods: Low-grade glioma patients treated at our institution from 1998 to 2015 and assessable for both RTOG and EORTC criteria were included to analyze their concordance. Surgery extension, postsurgical treatments, molecular characteristics (IDH mutation, MGMT methylation and 1p/19q codeletion) were recorded. Results: We included 99 patients. The concordance was low (50.5%; K = 0.127; p = 0.021) but for two subgroups: EORTC high-risk patients were also RTOG high-risk patients (concordance: 97.5%) and RTOG low-risk patients were also EORTC low-risk patients (concordance: 90.9%). Conclusion: The concordance between RTOG and EORTC criteria is low. Thus, clinical trials adopting different risk criteria are not comparable.

Sex is an important prognostic factor for glioblastoma but not for nonglioblastoma

Background

Glioblastoma (GBM) is the most common and most malignant glioma. Nonglioblastoma (non-GBM) gliomas (WHO Grades II and III) are invasive and also often fatal. The goal of this study is to determine whether sex differences exist in glioma survival.

Methods

Data were obtained from the National Cancer Database (NCDB) for years 2010 to 2014. GBM (WHO Grade IV; N = 2073) and non-GBM (WHO Grades II and III; N = 2963) were defined using the histology grouping of the Central Brain Tumor Registry of the United States. Non-GBM was divided into oligodendrogliomas/mixed gliomas and astrocytomas. Sex differences in survival were analyzed using Kaplan-Meier and multivariable Cox proportional hazards models adjusted for known prognostic variables.

Results

There was a female survival advantage in patients with GBM both in the unadjusted (P = .048) and adjusted (P = .003) models. Unadjusted, median survival was 20.1 months (95% CI: 18.7-21.3 months) for women and 17.8 months (95% CI: 16.9-18.7 months) for men. Adjusted, median survival was 20.4 months (95% CI: 18.9-21.6 months) for women and 17.5 months (95% CI: 16.7-18.3 months) for men. When stratifying by age group (18-55 vs 56+ years at diagnosis), this female survival advantage appeared only in the older group, adjusting for covariates (P = .017). Women (44.1%) had a higher proportion of methylated MGMT (O⁶-methylguanine-DNA methyltransferase) than men (38.4%). No sex differences were found for non-GBM.

Conclusions

Using the NCDB data, there was a statistically significant female survival advantage in GBM, but not in non-GBM.

Contrast-enhancement in supratentorial low-grade gliomas: a classic prognostic factor in the molecular age

BACKGROUND

Contrast enhancement (CE) is found in 10-60% of low-grade gliomas. Its prognostic significance is controversial, and its correlation with IDH mutations and 1p/19q codeletion is elusive. The aim of this study is to investigate whether CE is associated with molecular characteristics of low-grade gliomas and uncover its prognostic value.

MATERIALS AND METHODS

All confirmed histological cases of low-grade gliomas diagnosed at our institution between years 2000-2016 were reviewed (n = 102). Spinal and brainstem localization, only-biopsied tumours with ring-like enhancement and incomplete medical records were excluded.

RESULTS

Mean age was 42 years ( ± 13.9 years), and 63.6% were male. The median follow-up time was 79.8 months. CE was present on 25% of preoperative MRI, and 25% of patients were considered high-risk according to Pignatti score. Most were astrocytomas (67%) and 87.2% were surgically removed. IDH mutation was found in 64.6% of tumour samples, and 18.8% had a 1p/19q codeletion. No subgroup differences were observed according to CE except for presurgical performance status and postoperative chemotherapy. IDH status and 1p/19q codeletion were evenly distributed. On univariate analysis, age, size > 6 cm, CE, extent of resection, Pignatti score, IDH mutation and 1p/19q codeletion were significantly associated to OS. On multivariate analysis, only CE and IDH status were independently associated to OS. CE remained a significant prognostic factor in IDH-mutant non-codeleted tumours when analysed by tumour subtype.

CONCLUSION

CE in low-grade gliomas provides prognostic information in IDH-mutant non-codeleted tumours, although its meaning remains uncertain in IDH-wildtype gliomas.

Intratumoral temozolomide in spontaneous canine gliomas: feasibility of a novel therapy using implanted microcylinders

Entotherapy[Link] an image‐guided drug‐eluting microcylinder platform, has the potential to bypass the limitations of systemic chemotherapy use in the treatment of canine brain tumours. Gliomas, which are common in dogs and also represent the majority of fatal brain tumours in humans, can be amenable to chemotherapy with temozolomide. Biopolymer microcylinders conjugated with temozolomide and gadolinium were implanted into partially resected tumours of four client‐owned dogs with gliomas. All four dogs presented with generalized seizures and had mild to no neurologic deficits at the time of craniotomy. All dogs underwent craniotomy for implantation of the microcylinders into partially resected gliomas (glioblastoma multiforme {n = 1} or oligodendroglioma {n = 3}). All dogs recovered well from the craniotomy and implantation procedure. This novel procedure appears to be feasible and tolerated in tumour‐bearing dogs. A future controlled clinical study can now aim to evaluate the microcylinder implantation for long‐term efficacy.

Evidence for Improving Outcome Through Extent of Resection

Surgical resection plays a central role in the management of gliomas however many tumors are within areas resulting in sensorimotor and cognitive consequences. This article reviews the evidence in support of extent of resection to improve survival, symptom management, and time to malignant transformation in low-grade gliomas. The authors summarize the evolving literature regarding the role of maximal safe resection in light of WHO subclassification of low-grade gliomas. Long lasting neurological deficits following glioma resection may hinder both survival and quality of life. New insights into glioma related central nervous system plasticity impact both surgical planning and timing of interventions.

Brain Mapping as Helpful Tool in Brain Glioma Surgical Treatment-Toward the "Perfect Surgery"?

Gliomas are the most common primary malignant brain tumours in adults, representing nearly 80%, with poor prognosis in their high-grade forms. Several variables positively affect the prognosis of patients with high-grade glioma: young age, tumour location, radiological features, recurrence, and the opportunity to perform post-operative adjuvant therapy. Low-grade gliomas are slow-growing brain neoplasms of adolescence and young-adulthood, preferentially involving functional areas, particularly the eloquent ones. It has been demonstrated that early surgery and higher extent rate ensure overall longer survival time regardless of tumour grading, but nowadays, functional preservation that is as complete as possible is imperative. To achieve the best surgical results, along with the best functional results, intraoperative mapping and monitoring of brain functions, as well as different anaesthesiology protocols for awake surgery are nowadays being widely adopted. We report on our experience at our institution with 28 patients affected by malignant brain tumours who underwent brain mapping-aided surgical resection of neoplasm: 20 patients underwent awake surgical resection and 8 patients underwent asleep surgical resection. An analysis of the results and a review of the literature has been performed.

The Risk Assessment in Low-Grade Gliomas: An Analysis of the European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) criteria

Diffuse low-grade gliomas (LGG) are rare tumors that affect young adult patients. The European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) have both developed their own clinical prognostic scores to assist clinicians in treatment decision-making. These criteria have been used to include patients in phase III studies. To date, it is unknown which is the best score to define the prognosis of LGG. Additionally, a pure clinical classification is probably not a sufficiently informative basis for choosing the proper treatment in different situations. A combined score with both clinical and molecular features will likely be indispensable.

Surgical Considerations in the Optimal Management of Patients with Malignant Brain Tumors

OPINION STATEMENT

Advances in technology are revolutionizing medicine and the limits of what we can offer to our patients. In neurosurgery, technology continues to reduce morbidity, increase surgical accuracy, facilitate tissue acquisition, and promote novel techniques for prolonging survival in patients with neuro-oncologic disease. Surgery has been the backbone of glioma diagnosis and treatment by providing adequate, high quality material for precise histologic diagnosis, and genomic characterization in the setting of significant intratumoral heterogeneity, thus allowing personalized treatment selection in the clinic. The ability to obtain and accurately measure the maximal extent of resection in glioma surgery also remains a central role of the neurosurgeon in managing this cancer. To meet these goals, today's operating room has transformed from the traditional operating table and anesthesia machine to include neuronavigation instrumentation, intraoperative computed tomography, and magnetic resonance imaging scanners, advanced surgical microscopes fitted with fluorescent light filters, and electrocorticography machines. While surgeons, oncologists, and radiation oncologists all play unique critical roles in the care of patients with malignant gliomas, familiarity with developing techniques in complimentary subspecialties can enhance coordination of patient care, research productivity, professional interactions, and patient confidence and comfort with the physician team. Herein, we provide a summary of the advances in the field of neurosurgical oncology which allow more precise and optimal surgical resection for patients with malignant gliomas.

Surgical Management of Incidental Gliomas

Detailed brain imaging studies discover gliomas incidentally before clinical symptoms or signs show. These tumors represent an early stage in the natural history of gliomas. Left untreated, they are likely to progress to a symptomatic stage and transform to malignant gliomas. A greater extent of resection delays the onset of malignant transformation and prolongs patient survival. Because incidental gliomas are typically smaller and less likely to be in eloquent brain locations, there is a strong case for early surgical intervention to maximize resection and improve outcomes. This article discusses developments in the surgical management of low-grade gliomas.

Oligodendroglioma resection: a Surveillance, Epidemiology, and End Results (SEER) analysis

OBJECTIVE

The available evidence suggests that the clinical benefits of extended resection are limited for chemosensitive tumors, such as primary CNS lymphoma. Oligodendroglioma is generally believed to be more sensitive to chemotherapy than astrocytoma of comparable grades. In this study the authors compare the survival benefit of gross-total resection (GTR) in patients with oligodendroglioma relative to patients with astrocytoma.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) Program (1999–2010) database, the authors identified 2378 patients with WHO Grade II oligodendroglioma (O2 group) and 1028 patients with WHO Grade III oligodendroglioma (O3 group). Resection was defined as GTR, subtotal resection, biopsy only, or no resection. Kaplan-Meier and multivariate Cox regression survival analyses were used to assess survival with respect to extent of resection.

RESULTS

Cox multivariate analysis revealed that the hazard of dying from O2 and O3 was comparable between patients who underwent biopsy only and GTR (O2: hazard ratio [HR] 1.06, 95% confidence interval [CI] 0.73–1.53; O3: HR 1.18, 95% CI 0.80–1.72). A comprehensive search of the published literature identified 8 articles without compelling evidence that GTR is associated with improved overall survival in patients with oligodendroglioma.

CONCLUSIONS

This SEER-based analysis and review of the literature suggest that GTR is not associated with improved survival in patients with oligodendroglioma. This finding contrasts with the documented association between GTR and overall survival in anaplastic astrocytoma and glioblastoma. The authors suggest that this difference may reflect the sensitivity of oligodendroglioma to chemotherapy as compared with astrocytomas.

Procarbazine, lomustine and vincristine toxicity in low-grade gliomas

Background

Procarbazine, lomustine, and vincristine (pcv) significantly improve survival outcomes in lgg (low-grade gliomas). Administration of pcv to lgg patients increased tremendously over the past years as it went from 2 patients per year between 2005 and 2012 to 23 patients in 2015 only in our centre. However, serious hematological and non-hematological adverse events may occur. The purpose of this study was to evaluate the toxicity of pcv and its clinical relevance in our practice.

Methods

We retrospectively reviewed the charts of 57 patients with lgg who received pcv at the Centre hospitalier de l'Université de Montréal between 1 January 2005 and 27 July 2016.

Results

Procarbazine, lomustine, and vincristine were associated with severe hematological toxicity as clinically significant grade 3 anemia, neutropenia, and thrombocytopenia occurred in 7%, 10%, and 28% of patients, respectively. Other frequent adverse events such as the increase of liver enzymes, cutaneous rash, neurotoxicity, and vomiting occurred in 65%, 26%, 60%, and 40% of patients, respectively. Patients with prophylactic trimethoprim/sulfamethoxazole had more grade 3 hematological toxicity with pcv, especially anemia (p = 0.040) and thrombocytopenia (p = 0.003) but we found no increase in pcv toxicity in patients on concurrent anticonvulsants. Patients with grade 3 neutropenia had a significantly lower survival (median survival 44.0 months vs. 114.0 months, p = 0.001). Patients who were given pcv at diagnosis had more grade 3 anemia than those who received it at subsequent lines of treatment (p = 0.042).

Conclusion

Procarbazine, lomustine, and vincristine increase survival in lgg but were also associated with major hematologic, hepatic, neurologic, and cutaneous toxicity. Anti-Pneumocystis jiroveci pneumonia (pjp) prophylaxis, but not anticonvulsants, enhances hematologic toxicity.

Prognostic markers for survival in patients with oligodendroglial tumors; a single-institution review of 214 cases

Background

In the 2016 WHO classification, the diagnosis of oligodendroglioma has been restricted to IDH mutated, 1p19q codeleted tumors (IDHmut-codel). IDHmut oligoastrocytoma is now classified either as oligodendroglioma or astrocytoma based on presence of 1p19q codeletion. There is growing evidence that this molecular classification more closely reflects patient outcome. Due to the strong association between IDHmut-codel with oligodendroglial morphology, the additional impact of these markers on prognostic accuracy is largely unknown. Our aim was to assess the prognostic impact of IDHmut-codel in an unselected cohort of morphologically classified oligodendroglial tumors.

Methods

We performed a retrospective chart review of oligodendroglial tumors (WHO grade II and III) operated since 1983. A total of 214 tumors were included, and molecular information was available for 96 tumors. The prognostic impact of IDHmut-codel together with clinical parameters was analyzed by multivariate Cox regression.

Results

IDHmut-codel was registered in 64 tumors while for 150 tumors the molecular profile was negative for IDHmut-codel, unknown or incomplete. Comparison between the two groups showed that patients with IDHmut-codel tumors were younger (42 vs. 48 years), had more frequent frontal tumor location (48 vs. 33%) and presented more often with seizures (72 vs. 51%) and no signs of neurological impairment (14 vs. 30%) than patients harboring tumors with unknown or incomplete molecular profile. Multivariate survival analysis identified young age (HR 1.78 ≥ 40 years), the absence of neurological deficits or personality changes (HR 0.57), frontal tumor location (HR 0.64) and the presence of IDHmut-codel (HR 0.50) as independent predictors for longer survival, whereas tumor grade was not.

Conclusion

In this unselected single-institution cohort, the presence of IDHmut-codel was associated with more beneficial clinical parameters and was identified as an independent prognostic factor. We conclude that the classical oligodendroglioma genotype provides additional prognostic data beyond clinical characteristics, morphology and tumor grade.

Postoperative functional status in patients with supratentorial superficial low-grade glioma

Background

We investigated the functional status of adult supratentorial superficial low-grade glioma (ASS-LGG) after surgery and analyzed its relevant factors to guide the therapeutic strategy and improve the life quality of these patients.

Methods

Clinical materials from January 2008 to December 2010 in 104 adults with ASS-LGG were analyzed retrospectively. The follow-up period ranged from 6 months to 1.5 years. The logistic regression was used to evaluate the preoperative and postoperative variation of functional status in patients to disclose the relevant factors affecting postoperative functional status, such as age, gender, the duration of symptom, size and location of the tumor, hemisphere, resection degree, and tumor pathologic grade and preoperative Karnofsky performance status (Pre-KPS).

Results

Four out of nine candidate factors are related to the postoperative functional status. They are age less than 40 years, the size of tumor less than 5 cm in diameter, tumor located in the right hemisphere, and limited resection of tumor in the eloquent area.

Conclusions

It seems more meaningful to evaluate the functional status of the patients with ASS-LGG on the basis of these clinical features, involving age, tumor size, location, and extent of resection.

Intraoperative imaging techniques for glioma surgery

Gliomas are CNS neoplasms that infiltrate the surrounding brain parenchyma, complicating their treatment. Tools that increase extent of resection while preventing neurological deficit are essential to improve prognosis of patients diagnosed with gliomas. Tools such as intraoperative MRI, ultrasound and fluorescence-guided microsurgery have been used in the surgical resection of CNS gliomas with the goal of maximizing extent of resection to improve patient outcomes. In addition, emerging experimental techniques, for example, optical coherence tomography and Raman spectroscopy are promising techniques which could 1 day add to the increasing armamentarium used in the surgical resection of CNS gliomas. Here, we present the potential advantages and limitations of these imaging techniques for the purposes of identifying gliomas in the operating room.

Comparative volumetric analysis of the extent of resection of molecularly and histologically distinct low grade gliomas and its role on survival

The authors investigate the role of extent of resection (EOR) and genetic markers on patient outcome and survival for LGGs. We conducted a retrospective cohort between 2005 and 2015, of 109 adult patients who underwent surgery for a LGG by a single surgeon. Volumetric computations of MRI studies were conducted to evaluate the EOR, and genetic markers (IDH1, 1p/19q co-deletion, and p53) were assessed and their effects on survival and neurological outcome were evaluated. The median EOR was 88.1%. Permanent postoperative neurological deficits were seen in 4.6% of patients. EOR was a significant predictor for both overall survival (OS) (hazard ratio [HR] = 0.979, 95% CI 0.961-0.980, p = 0.029) and progression free survival (PFS) (HR = 0.982, 95% CI 0.968-0.997, p = 0.018). Malignant progression free survival (MPFS) was predicted by the 1p/19q co-deletion (HR = 0.148, 95% CI 0.019-1.148, p = 0.048). Patients with EOR of 100% had a significantly better OS than EOR less than 90% (p = 0.038). Patients with an EOR of at least 76% had a better OS than EOR less than 76% (p = 0.025). Patients with an EOR of at least 71% had a better PFS than EOR less than 71% (p = 0.030). Preoperative tumor volume was found to have significant association with EOR (R² = 0.049, p = 0.031). Increased EOR is associated with improved OS and PFS survival outcomes, while 1p/19q co-deletion provides improved MPFS. Understanding both surgical resections and molecular markers of the tumor are important for effective management of LGG patients.

Decline in executive functions and speed in suspected low-grade gliomas: A 3-year follow-up of a clinical cohort

Changes over time in information processing speed and executive functions (EFs) were studied in patients with suspected low-grade gliomas (LGG) 3 years after diagnosis. Using a person-oriented approach, the study aimed at focusing solely on two cognitive domains known to be significant in the understanding of the impact of white matter diseases. The Barkley's hybrid model of EFs was used as a theoretical framework for the evaluation of EFs. The majority of the patients showed a decline in at least one of these two cognitive domains indicating that the progress of diffuse brain injury cannot be neglected in understanding neuropsychological changes over time in patients with LGG. In our sample, higher age and radiological signs of radiotherapy-induced brain atrophy were seen in patients with a decline in both domains.

Serum endocan levels before and after surgery on low-grade gliomas

BACKGROUND

Endocan has been shown to be a marker for several cancers and may show degree of malignancy. The aim of this study is to assess serum levels of endocan before and after surgery on low-grade gliomas (LGGs).

METHODS

Endocan was assayed by commercially available enzyme-linked immunosorbent assay (ELISA) kits in a total of 19 patients and 12 controls. Serial serum samples were obtained before and after surgery (1^st day, 1^st week, and 1^st month of surgery). Control samples were collected from cord blood during cesarean section. The results were compared with control brain tissues.

RESULTS

Controls showed significantly lower serum endocan levels compared to before and after surgery (P < 0.05). There is a trend of increase in mean serum levels from before surgery and during the very early period after surgery (during first week); however, in the first month, mean serum levels became lower.

CONCLUSION

Endocan, a vital molecule for angiogenesis, is highly expressed before and after surgery in LGGs, but long-term data is needed. Furthermore, future studies should include high-grade gliomas to discuss whether endocan is associated with recurrence and response to treatment.

Connectomic profile and clinical phenotype in newly diagnosed glioma patients

Gliomas are primary brain tumors, originating from the glial cells in the brain. In contrast to the more traditional view of glioma as a localized disease, it is becoming clear that global brain functioning is impacted, even with respect to functional communication between brain regions remote from the tumor itself. However, a thorough investigation of glioma-related functional connectomic profiles is lacking. Therefore, we constructed functional brain networks using functional MR scans of 71 glioma patients and 19 matched healthy controls using the automated anatomical labelling (AAL) atlas and interregional Pearson correlation coefficients. The frequency distributions across connectivity values were calculated to depict overall connectomic profiles and quantitative features of these distributions (full-width half maximum (FWHM), peak position, peak height) were calculated. Next, we investigated the spatial distribution of the connectomic profile. We defined hub locations based on the literature and determined connectivity (1) between hubs, (2) between hubs and non-hubs, and (3) between non-hubs. Results show that patients had broader and flatter connectivity distributions compared to controls. Spatially, glioma patients particularly showed increased connectivity between non-hubs and hubs. Furthermore, connectivity distributions and hub-non-hub connectivity differed within the patient group according to tumor grade, while relating to Karnofsky performance status and progression-free survival. In conclusion, newly diagnosed glioma patients have globally altered functional connectomic profiles, which mainly affect hub connectivity and relate to clinical phenotypes. These findings underscore the promise of using connectomics as a future biomarker in this patient population.

The effect of pregnancy on survival in a low-grade glioma cohort

OBJECTIVE

The impact of pregnancy on survival in female patients with low-grade glioma (LGG) is unknown and controversial. The authors designed a retrospective cohort study on prospectively collected registry data to assess the influence of pregnancy and child delivery on the survival of female patients with LGG.

METHODS

In Norway, the reporting of all births and cancer diagnoses to the Medical Birth Registry of Norway (MBRN) and the Cancer Registry of Norway (CRN), respectively, is compulsory by law. Furthermore, every individual has a unique 11-digit identification number. The CRN was searched to identify all female patients with a histologically confirmed diagnosis of World Health Organization (WHO) Grade II astrocytoma, oligoastrocytoma, oligodendroglioma, or pilocytic astrocytoma who were 16–40 years of age at the time of diagnosis during the period from January 1, 1970, to December 31, 2008. Obstetrical information was obtained from the MBRN for each patient. The effect of pregnancy on survival was evaluated using a Cox model with parity as a time-dependent variable.

RESULTS

The authors identified 65 patients who gave birth to 95 children after an LGG diagnosis. They also identified 281 patients who did not give birth after an LGG diagnosis. The median survival was 14.3 years (95% CI 11.7–20.6 years) for the entire study population. The effect of pregnancy was insignificant in the multivariate model (HR 0.71, 95% CI 0.35–1.42).

CONCLUSIONS

Pregnancy does not seem to have an impact on the survival of female patients with LGG.

Astrocytic gliomas WHO grades II and III

World Health Organization grades II and III lower-grade astrocytomas are a challenging area in neuro-oncology. One the one hand, for proper diagnosis, the analysis of molecular factors, especially mutation status of isocitrate dehydrogenase and 1p/19q status in the tumor status needs to be done in addition to classical neuropathology. Further, the high clinical and prognostic value of a maximal safe resection requires a profound knowledge of presurgical diagnosis and surgical as well as imaging techniques to ensure optimal outcome for patients. Also medical treatment may be more intensive than previously believed, with randomized trials providing evidence for a benefit in overall survival by combined chemoradiation versus radiation alone. A critical problem concerns the considerable undesirable effects of therapeutic interventions on long-term health-related quality of life, cognitive and functional outcome as well as future developments in this still difficult disease that will need to be addressed in future trials.

Atypical pediatric ganglioglioma is common and associated with a less favorable clinical course

OBJECT Ganglioglioma (GG) is commonly recognized as a low-grade tumor located in the temporal lobe, often presenting with seizures. Most are amenable to complete resection and are associated with excellent oncological outcome. The authors encountered several GGs in various locations, which seem to have a less favorable clinical course than GGs in the temporal lobe. METHODS The authors performed a single-center retrospective review of all children with a histological diagnosis of GG who were treated at Children's Hospital Colorado between 1997 and 2013. Each tumor was categorized by 2 pediatric neuroradiologists as typical or atypical based on preoperative MRI appearance. Typical lesions were cortically based, within a single cerebral lobe, well-circumscribed, and solid or mixed solid/cystic. The treatment and clinical course of each patient was analyzed. RESULTS Thirty-seven children were identified, with a median age at presentation of 8.2 years and median follow-up of 38.0 months. Eighteen tumors (48.6%) were typical and 19 (51.4%) were atypical. All typical lesions presented with seizures, whereas no atypical lesions did so. Sixteen (88.9%) typical lesions were located in the temporal lobe. In the atypical group, tumor location was variable, including 11 (57.9%) in the brainstem. Death during follow-up was statistically more common in the atypical group (31.6% vs 0%, p = 0.02). Gross-total resection (GTR) was achieved for 15 of 16 typical tumors (93.8%), compared with 3 atypical tumors (15.8%, p < 0.0001). Presentation with seizure or non-brainstem location were each associated with survival (p = 0.02 and 0.004, respectively). The presence of mutation in BRAF exon 15 did not differ between the 2 groups. CONCLUSIONS Pediatric GG with typical imaging features is associated with excellent rates of GTR and overall survival. Atypical GG is commonly encountered, less amenable to GTR, and associated with a worse outcome. This may relate to anatomical or biological characteristics and merits further investigation.

Surgical approaches for the gliomas

Neurosurgical intervention remains the first step in effective glioma management. Mounting evidence suggests that cytoreduction for low- and high-grade gliomas is associated with a survival benefit. Beyond conventional neurosurgical principles, an array of techniques have been refined in recent years to maximize the effect of the neurosurgical oncologist and facilitate the impact of subsequent adjuvant therapy. With intraoperative mapping techniques, aggressive microsurgical resection can be safely pursued even when tumors occupy essential functional pathways. Other adjunct techniques, such as intraoperative magnetic resonance imaging, intraoperative ultrasonography, and fluorescence-guided surgery, can be valuable tools to safely reduce the tumor burden of low- and high-grade gliomas. Taken together, this collection of surgical strategies has pushed glioma extent of resection towards the level of cellular resolution.

The role of radiotherapy in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

QUESTIONS

(1) What is the optimal role of external beam radiotherapy in the management of adult patients with newly diagnosed low-grade glioma (LGG) in terms of improving outcome (i.e., survival, complications, seizure control or other reported outcomes of interest)? (2) Which radiation strategies (dose, timing, fractionation, stereotactic radiation, brachytherapy, chemotherapy) improve outcomes compared to standard external beam radiation therapy in the initial management of low grade gliomas in adults? (3) Do specific factors (e.g., age, volume, extent of resection, genetic subtype) identify subgroups with better outcomes following radiation therapy than the general population of adults with newly diagnosed low-grade gliomas?

TARGET POPULATION

These recommendations apply to adults with newly diagnosed diffuse LGG.

RECOMMENDATIONS

OUTCOMES IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level I Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong progression free survival, irrespective of extent of resection. Level II Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults as an equivalent alternative to observation in preserving cognitive function, irrespective of extent of resection. Level III Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults to improve seizure control in patients with epilepsy and subtotal resection. Level III Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong overall survival in patients with subtotal resection. Level III Consideration of the risk of radiation induced morbidity, including cognitive decline, imaging abnormalities, metabolic dysfunction and malignant transformation, is recommended when the delivery of radiotherapy is selected in the management of newly diagnosed low-grade glioma in adults. STRATEGIES OF RADIOTHERAPY IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA: Level I Lower dose radiotherapy is recommended as an equivalent alternative to higher dose immediate postoperative radiotherapy (45-50.4 vs. 59.4-64.8 Gy) in the management of newly diagnosed low-grade glioma in adults with reduced toxicity. Level III Delaying radiotherapy until recurrence or progression is recommended as an equivalent alternative to immediate postoperative radiotherapy in the management of newly diagnosed low-grade glioma in adults but may result in shorter time to progression. Level III The addition of chemotherapy to radiotherapy is not recommended over whole brain radiotherapy alone in the management of low-grade glioma, as it provides no additional survival benefit. Level III Limited-field radiotherapy is recommended over whole brain radiotherapy in the management of low-grade glioma. Level III Either stereotactic radiosurgery or brachytherapy are recommended as acceptable alternatives to external radiotherapy in selected patients. PROGNOSTIC FACTORS IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level II It is recommended that age greater than 40 years, astrocytic pathology, diameter greater than 6 cm, tumor crossing the midline and preoperative neurological deficit be considered as negative prognostic indicators when predicting overall survival in adult low grade glioma patients treated with radiotherapy. Level II It is recommended that smaller tumor size, extent of surgical resection and higher mini-mental status exam be considered as positive prognostic indicators when predicting overall survival and progression free survival in patients in adult low grade glioma patients treated with radiotherapy. Level III It is recommended that seizures at presentation, presence of oligodendroglial histological component and 1p19q deletion (along with additional relevant factors-see Table 1) be considered as positive prognostic indicators when predicting response to radiotherapy in adults with low grade gliomas. Level III It is recommended that increasing age, decreasing performance status, decreasing cognition, presence of astrocytic histological component (along with additional relevant factors (see Tables 1, 2) be considered as negative prognostic indicators when predicting response to radiotherapy.

The role of surgery in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

QUESTION

Should patients with imaging suggestive of low grade glioma (LGG) undergo observation versus treatment involving a surgical procedure?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

Surgical resection is recommended over observation to improve overall survival for patients with diffuse low-grade glioma (Level III) although observation has no negative impact on cognitive performance and quality of life (Level II).

QUESTION

What is the impact of extent of resection on progression free survival (PFS) or overall survival (OS) in LGG patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

IMPACT OF EXTENT OF RESECTION ON PFS:

LEVEL II

It is recommended that GTR or STR be accomplished instead of biopsy alone when safe and feasible so as to decrease the frequency of tumor progression recognizing that the rate of progression after GTR is fairly high.

IMPACT OF EXTENT OF RESECTION ON OS

LEVEL III

Greater extent of resection can improve OS in LGG patients.

QUESTION

What tools are available to increase extent of resection in LGG patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

INTRAOPERATIVE MRI DURING SURGERY:

LEVEL III

The use of intraoperative MRI should be considered as a method of increasing the extent of resection of LGGs.

QUESTION

What is the impact of surgical resection on seizure control and accuracy of pathology in low grade glioma patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

SURGICAL RESECTION AND SEIZURE CONTROL:

LEVEL III

After taking into account the patient's clinical status and tumor location, gross total resection is recommended for patients with diffuse LGG as a way to achieve more favorable seizure control.

ACCURACY OF DIAGNOSIS

LEVEL III

Taking into account the patient's clinical status and tumor location, surgical resection should be carried out to maximize the chance of accurate diagnosis.

QUESTION

What tools can improve the safety of surgery for LGGs in eloquent locations?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

PREOPERATIVE IMAGING:

LEVEL III

It is recommended that preoperative functional MRI and diffusion tensor imaging be utilized in the appropriate clinical setting to improve functional outcome after surgery for LGG.

INTRAOPERATIVE MAPPING OF TUMORS IN ELOQUENT AREAS

LEVEL III

Intraoperative mapping is recommended for patients with diffuse LGGs in eloquent locations compared to patients with non-eloquently located diffuse LGGs as a way of preserving function.

The Value of Pre- and Intraoperative Adjuncts on the Extent of Resection of Hemispheric Low-Grade Gliomas: A Retrospective Analysis

BACKGROUND

To achieve maximal resection with minimal risk of postoperative neurologic morbidity, different neurosurgical adjuncts are being used during low-grade glioma (LGG) surgery.

OBJECTIVES

To investigate the effect of pre- and intraoperative adjuncts on the extent of resection (EOR) of hemispheric LGGs.

METHODS

Medical records were reviewed to identify patients of any sex, ≥ 18 years of age, who underwent LGG surgery at X Hospital between January 2005 and July 2013. Patients were divided into eight subgroups based on the use of various combinations of a neuronavigation system alone (NN), functional MRI-diffusion tensor imaging (fMRI-DTI) guided neuronavigation (FD), intraoperative MRI (MR), and direct electrical stimulation (DES). Initial and residual tumors were measured, and mean EOR was compared between groups.

RESULTS

Of all 128 patients, gross total resection was achieved in 23.4%. Overall mean EOR was 81.3% ± 20.5%. Using DES in combination with fMRI-DTI (mean EOR: 86.7% ± 12.4%) on eloquent tumors improved mean EOR significantly after adjustment for potential confounders when compared with NN alone (mean EOR: 76.4% ± 25.5%; p = 0.001).

CONCLUSIONS

Using DES in combination with fMRI and DTI significantly improves EOR when LGGs are located in eloquent areas compared with craniotomies in which only NN was used.

Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

BACKGROUND

In most people with low-grade gliomas (LGG), the primary treatment regimen remains a combination of surgery followed by postoperative radiotherapy. However, the optimal timing of radiotherapy is controversial. It is unclear whether to use radiotherapy in the early postoperative period, or whether radiotherapy should be delayed until tumour progression occurs.

OBJECTIVES

To assess the effects of early postoperative radiotherapy versus radiotherapy delayed until tumour progression for low-grade intracranial gliomas in people who had initial biopsy or surgical resection.

SEARCH METHODS

We searched up to September 2014 the following electronic databases: the Cochrane Register of Controlled Trials (CENTRAL, Issue 8, 2014), MEDLINE (1948 to Aug week 3, 2014), and EMBASE (1980 to Aug week 3, 2014) to identify trials for inclusion in this Cochrane review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared early versus delayed radiotherapy following biopsy or surgical resection for the treatment of people with newly diagnosed intracranial LGG (astrocytoma, oligodendroglioma, mixed oligoastrocytoma, astroblastoma, xanthoastrocytoma, or ganglioglioma). Radiotherapy may include conformal external beam radiotherapy (EBRT) with linear accelerator or cobalt-60 sources, intensity-modulated radiotherapy (IMRT), or stereotactic radiosurgery (SRS).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed the trials for inclusion and risk of bias, and extracted study data. We resolved any differences between review authors by discussion. Adverse effects were also extracted from the study report. We performed meta-analyses using a random-effects model with inverse variance weighting.

MAIN RESULTS

We included one large, multi-institutional, prospective RCT, involving 311 participants; the risk of bias in this study was unclear. This study found that early postoperative radiotherapy is associated with an increase in time to progression compared to observation (and delayed radiotherapy upon disease progression) for people with LGG but does not significantly improve overall survival (OS). The median progression-free survival (PFS) was 5.3 years in the early radiotherapy group and 3.4 years in the delayed radiotherapy group (hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.45 to 0.77; P value < 0.0001; 311 participants; 1 trail; low quality evidence). The median OS in the early radiotherapy group was 7.4 years, while the delayed radiotherapy group experienced a median overall survival of 7.2 years (HR 0.97, 95% CI 0.71 to 1.33; P value = 0.872; 311 participants; 1 trail; low quality evidence). The total dose of radiotherapy given was 54 Gy; five fractions of 1.8 Gy per week were given for six weeks. Adverse effects following radiotherapy consisted of skin reactions, otitis media, mild headache, nausea, and vomiting. Rescue therapy was provided to 65% of the participants randomised to delayed radiotherapy. People in both cohorts who were free from tumour progression showed no differences in cognitive deficit, focal deficit, performance status, and headache after one year. However, participants randomised to the early radiotherapy group experienced significantly fewer seizures than participants in the delayed postoperative radiotherapy group at one year (25% versus 41%, P value = 0.0329, respectively).

AUTHORS' CONCLUSIONS

Given the high risk of bias in the included study, the results of this analysis must be interpreted with caution. Early radiation therapy was associated with the following adverse effects: skin reactions, otitis media, mild headache, nausea, and vomiting. People with LGG who undergo early radiotherapy showed an increase in time to progression compared with people who were observed and had radiotherapy at the time of progression. There was no significant difference in overall survival between people who had early versus delayed radiotherapy; however, this finding may be due to the effectiveness of rescue therapy with radiation in the control arm. People who underwent early radiation had better seizure control at one year than people who underwent delayed radiation. There were no cases of radiation-induced malignant transformation of LGG. However, it remains unclear whether there are differences in memory, executive function, cognitive function, or quality of life between the two groups since these measures were not evaluated.

Phase 2 study of temozolomide-based chemoradiation therapy for high-risk low-grade gliomas: preliminary results of Radiation Therapy Oncology Group 0424

PURPOSE

Radiation Therapy Oncology Group (RTOG) 0424 was a phase 2 study of a high-risk low-grade glioma (LGG) population who were treated with temozolomide (TMZ) and radiation therapy (RT), and outcomes were compared to those of historical controls. This study was designed to detect a 43% increase in median survival time (MST) from 40.5 to 57.9 months and a 20% improvement in 3-year overall survival (OS) rate from 54% to 65% at a 10% significance level (1-sided) and 96% power.

METHODS AND MATERIALS

Patients with LGGs with 3 or more risk factors for recurrence (age ≥40 years, astrocytoma histology, bihemispherical tumor, preoperative tumor diameter of ≥6 cm, or a preoperative neurological function status of >1) were treated with RT (54 Gy in 30 fractions) and concurrent and adjuvant TMZ.

RESULTS

From 2005 to 2009, 129 evaluable patients (75 males and 54 females) were accrued. Median age was 49 years; 91% had a Zubrod score of 0 or 1; and 69%, 25%, and 6% of patients had 3, 4, and 5 risk factors, respectively. Patients had median and minimum follow-up examinations of 4.1 years and 3 years, respectively. The 3-year OS rate was 73.1% (95% confidence interval: 65.3%-80.8%), which was significantly improved compared to that of prespecified historical control values (P<.001). Median survival time has not yet been reached. Three-year progression-free survival was 59.2%. Grades 3 and 4 adverse events occurred in 43% and 10% of patients, respectively. One patient died of herpes encephalitis.

CONCLUSIONS

The 3-year OS rate of 73.1% for RTOG 0424 high-risk LGG patients is higher than that reported for historical controls (P<.001) and the study-hypothesized rate of 65%.

Supratentorial low-grade diffuse astrocytoma: medical management

Diffuse astrocytomas (DAs) represent less than 10% of all gliomas. They are diffusely infiltrating World Health Organization (WHO) grade II neoplasms that have a median survival in the range of 5-7 years, generally with a terminal phase in which they undergo malignant transformation to glioblastoma (GBM). The goals of treatment in addition to prolonging survival are therefore to prevent progression and malignant transformation, as well as optimally managing symptoms, primarily tumor-associated epilepsy. Available data suggest that the course of this disease is only minimally impacted by adjuvant therapies and that there does not seem to be much difference in terms of outcome of whether patients are treated in the adjuvant setting with irradiation or chemotherapy. We review the experience with chemotherapy as a treatment modality and offer some guidelines for its usage and discuss medical management of arising symptoms.

Role of surgical resection in low- and high-grade gliomas

OPINION STATEMENT

Central nervous system tumors are a major cause of morbidity and mortality in the United States. Outside of brain metastasis, low- and high-grade gliomas are the most common intrinsic brain tumors. Low-grade gliomas have a 5- and 10-year survival rate of 97 % and 91 %, respectively, when extent of resection is greater than 90 %. High-grade gliomas are extremely aggressive with the vast majority of patients experiencing recurrence and a median survival of 1 to 3 years. Survival of patients with both low- and high-grade gliomas is enhanced with maximal tumor resection. The pursuit of more aggressive extent of resection must be balanced with preservation of functional pathways. Several innovations in neurosurgical oncology have expanded our understanding of individualized patient neuroanatomy, physiology, and function. Emerging imaging technologies as well as intraoperative techniques have expanded our ability to resect maximal amounts of tumor while preserving essential function. Stimulation mapping of language and motor pathways is well-established for the safe resection of intrinsic brain lesions. Additional techniques including neuro-navigation, fluorescence-guided microsurgery using 5-aminolevulinic acid, intraoperative magnetic resonance imaging, and high-frequency ultrasonography can all be used to improve extent of resection in glioma patients.

Predictors of functional recovery in adults with posterior fossa ependymomas

OBJECT

After complete resection and radiation therapy, the 10-year overall survival rates for adult patients with posterior fossa ependymomas approach 85%. This favorable outcome profile emphasizes the critical importance of functional preservation to this patient population. Here, the authors identify predictors of functional outcome following microsurgical resection of adult posterior fossa ependymomas.

METHODS

The authors identified adult patients with newly diagnosed WHO Grade II posterior fossa ependymomas who underwent microsurgical resection at the Barrow Neurological Institute from 1990 to 2011. Clinical and radiographic variables were collected, including volumetric extent of resection, foramen of Luschka extension, cystic changes, peritumoral T2 signal changes, Karnofsky Performance Scale (KPS) score, National Institutes of Health Stroke Scale (NIHSS) score, progression-free survival (PFS), and overall survival (OS).

RESULTS

Forty-five patients were identified, with a median clinical follow-up of 103 months. The median PFS and OS were 6.8 and 8.6 years, respectively. Extent of resection and adjuvant radiotherapy were predictive of improved PFS (p = 0.005) and were nonsignificantly associated with improved OS. Univariate analysis revealed that tumor size (p < 0.001), cystic changes (p < 0.01), postoperative T2 signal (p < 0.01), and CSF diversion (p = 0.048) predicted functional and neurological recovery rates, based on KPS and NIHSS scores, respectively. Multivariate regression analysis identified tumor size (p < 0.001), cystic changes (p = 0.01), and CSF diversion (p = 0.02) as independent predictors of slower functional recovery, while only tumor size (p = 0.007) was an independent predictor of neurological recovery. Specifically, by 6 weeks postoperatively, baseline KPS score was recovered by only 43.8% of patients with tumors larger than 30 cm(3) (vs 72.4% patients with tumors < 30 cm(3)), 35.3% of patients with cystic tumors (vs 78.6% of patients with noncystic tumors), and 46.7% of patients requiring CSF diversion (vs 70% of patients not requiring CSF diversion).

CONCLUSIONS

Greater extent of resection and adjuvant radiotherapy significantly improve PFS in adult patients with posterior fossa ependymomas. Tumor size, cystic changes, and the need for CSF diversion were independent predictors of the rate of functional recovery in this patient population. Taken together, these functional outcome predictors may guide preoperative estimations of recovery following microsurgical resection.