Biopsy versus resection in the management of malignant gliomas: a systematic review and meta-analysis

Anti-glioblastoma Activity of Kaempferol via Programmed Cell Death Induction: Involvement of Autophagy and Pyroptosis

Glioblastoma is one of the most common and lethal intracranial malignant, and is still lack of ideal treatments. Kaempferol is a major nutrient found in various edible plants, which has exhibited the potential for the treatment of glioblastoma. However, the specific anti-glioma mechanism of kaempferol is yet to be studied. Herein, we aim to explore the mechanisms underlying the anti-glioma activity of kaempferol. Our results demonstrated that kaempferol suppresses glioma cell proliferation in vitro and inhibits tumor growth in vivo. Moreover, kaempferol raises ROS and decreases mitochondrial membrane potential in glioma cells. The high levels of ROS induce autophagy then ultimately trigger the pyroptosis of glioma cells. Interestingly, when we used 3-MA to inhibit autophagy, we found that the cleaved form of GSDME was also decreased, suggesting that kaempferol induces pyroptosis through regulating autophagy in glioma cells. In conclusion, this study revealed kaempferol possesses good anti-glioma activity by inducing ROS, and subsequently leads to autophagy and pyroptosis, highlighting its clinical potentials as a natural nutrient against glioblastoma.

Glioma surgery with awake language mapping versus generalized anesthesia: a systematic review

Awake craniotomy with language mapping is being increasingly applied to avoid postoperative language dysfunctions worldwide. However, the effectiveness and reliability of this technique remain unclear due to the paucity of studies comparing the awake craniotomy with general anesthesia. To determine the benefit of awake craniotomy for language, motor, and neurological functions, as well as other clinical outcomes, we searched Medline, Embase, the Cochrane Library, and the Chinese Biomedical Literature Database up to December 2019. Gray literatures were also searched. We included randomized and non-randomized controlled studies comparing awake craniotomy versus general anesthetic resection and reporting the language and neurological outcomes. Ten studies with 833 patients were included in the meta-analysis. The pooled risk ratio (RR) suggested no significant differences in language and neurological outcomes between general anesthesia group and awake craniotomy group without electrical stimulation. Awake craniotomy with electrical stimulation, however, was associated with improved late language and neurological outcomes (≥ 3 months) versus general anesthesia with pooled RR of 0.44 (95% CI = 0.20-0.96) and 0.49 (95% CI = 0.30-0.79), respectively. Awake craniotomy with electrical stimulation was also associated with better extent of resection with the pooled RR of 0.81 (95%CI = 0.71-0.92) and shorter hospital stay duration with the pooled weighted mean difference (WMD) of - 1.14 (95%CI = - 1.80 to - 0.48). This meta-analysis suggested that the application of awake craniotomy with electrical stimulation during glioma resection is associated with lower risks of long-term neurological and language deficits and higher extent of tumor resection, as well as shorter hospital stay duration.

Educational Case: Histologic and Molecular Features of Diffuse Gliomas

The following fictional cases are intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Proliferation-dominant high-grade astrocytoma: survival benefit associated with extensive resection of FLAIR abnormality region

OBJECTIVE

The aim of this study was to investigate the relationship between extent of resection (EOR) and survival in terms of clinical, molecular, and radiological factors in high-grade astrocytoma (HGA).

METHODS

Clinical and radiological data from 585 cases of molecularly defined HGA were reviewed. In each case, the EOR was evaluated twice: once according to contrast-enhanced T1-weighted images (CE-T1WI) and once according to fluid attenuated inversion recovery (FLAIR) images. The ratio of the volume of the region of abnormality in CE-T1WI to that in FLAIR images (VFLAIR/VCE-T1WI) was calculated and a receiver operating characteristic curve was used to determine the optimal cutoff value for that ratio. Univariate and multivariate analyses were performed to identify the prognostic value of each factor.

RESULTS

Both the EOR evaluated from CE-T1WI and the EOR evaluated from FLAIR could divide the whole cohort into 4 subgroups with different survival outcomes (p < 0.001). Cases were stratified into 2 subtypes based on VFLAIR/VCE-T1WI with a cutoff of 10: a proliferation-dominant subtype and a diffusion-dominant subtype. Kaplan-Meier analysis showed a significant survival advantage for the proliferation-dominant subtype (p < 0.0001). The prognostic implication has been further confirmed in the Cox proportional hazards model (HR 1.105, 95% CI 1.078-1.134, p < 0.0001). The survival of patients with proliferation-dominant HGA was significantly prolonged in association with extensive resection of the FLAIR abnormality region beyond contrast-enhancing tumor (p = 0.03), while no survival benefit was observed in association with the extensive resection in the diffusion-dominant subtype (p = 0.86).

CONCLUSIONS

VFLAIR/VCE-T1WI is an important classifier that could divide the HGA into 2 subtypes with distinct invasive features. Patients with proliferation-dominant HGA can benefit from extensive resection of the FLAIR abnormality region, which provides the theoretical basis for a personalized resection strategy.

Complete radiological response following subtotal resection in three glioblastoma patients under treatment with Tumor Treating Fields

Glioblastoma multiforme (GBM) treatment consists of surgery, radiotherapy and chemotherapy with Temozolomide (TMZ). After subtotal resection (STR), residual tumors rarely undergo spontaneous regression. Overall survival (OS) and progression-free survival (PFS) are reduced when compared with gross total resection. There is evidence that adding Tumor Treating Fields (TTFields) to standard management may lead to a significant increase in PFS and OS. In 2015 and 2016, STR was performed in 27 patients with GBM. Of these, four subsequently received TTFields therapy in addition to chemotherapy. The present study presents a series of three patients with GBM (44-54 years; isocitrate dehydrogenase wild-type, methylated O6-methylguanine-DNA methyltransferase promoter) that were treated with radiochemotherapy and TTFields after STR. Therapy with TTFields started concomitantly to TMZ following radiotherapy and was maintained for 14, 24 and 37 months. TTFields were used as monotherapy in one case, as TMZ treatment had to be stopped due to toxicity for 1 month. In all patients, TTFields therapy was well tolerated at high compliance levels, resulting in complete response (CR) after 4, 5 and 7 months, respectively. Two patients remain tumor-free at 16 and 40 months after STR. One patient exhibited multifocal recurrence 11 months after the beginning of TTFields treatment but remains alive, presenting a mild neurological decline 24 months after starting TTFields. All three presented patients gave written informed consent for their data to be published. In conclusion, the current report detailed three patients with GBM who underwent STR and were subsequently treated with TMZ and TTFields. TTFields treatment was tolerated well and was applied accurately and with high compliance by these patients, which may have contributed to the complete response. Four of the 27 patients treated with STR received additional TTFields treatment. Three of these 4 showed a CR, while a CR was observed only 2 of the remaining 23 patients without TTFields. The current series supports the effects in clinical practice, as demonstrated in recent clinical trials. The results also demonstrated that adjuvant TTFields therapy can structurally affect residual tumors after STR.

Hypofractionated stereotactic radiotherapy combined with chemotherapy or not in the management of recurrent malignant gliomas: A systematic review and meta-analysis

Hypofractionated stereotactic radiotherapy (HFSRT) is a common salvage treatment for recurrent malignant glioma (MG). However, it remains controversial whether the combination of HFSRT and chemotherapy could improve survival for patients with recurrent MG compared to HFSRT alone. The present systematic review and meta-analysis aims to investigate this question, and tries to determine to what extent the addition of chemotherapy to HFSRT affects survival. A systematic review was performed to analyse the survival for patients treated with HFSRT combined with chemotherapy or not. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were pooled with random effects; and standard mean difference (MD) with 95% CIs for OS were pooled using the same strategy. A total of 7 studies including 388 patients with recurrent MG were eligible for our study. The OS survival of patients receiving combination therapy ranged from 8.7 to 23 months, and the median OS of patients underwent HFSRT ranged from 3.9 to 12 months. The meta-analyses resulted in the pooled HR of 0.44 (95% CI 0.30-0.65, p < 0.0001) (Cochran Q statistic 4.70, P = 0.320, I² = 14.8%) and pooled standard MD of 0.80 months (95% CI 0.41-1.18, p < 0.001) (Cochran Q statistic 10.16, p = 0.71, I² = 50.8%). The present study suggests that HFSRT + chemotherapy confers a slight survival improvement for patients with recurrent MG as compared with sole HFSRT management. To draw a more solid conclusion, greater investigation is warranted.

Biopsy versus resection for high-grade glioma

BACKGROUND

This is an update of the original review published in the Cochrane Database of Systematic Reviews Issue 1, 2000 and updated in 2003, 2007 and 2010.People with a presumed high-grade glioma (HGG) identified by clinical evaluation and radiological investigation have two initial surgical options: biopsy or resection. In certain situations, such as severe raised intracranial pressure, surgical resection is clinically indicated. Where surgical resection is not feasible, biopsy is the only reasonable option. Most people fall somewhere between these extremes, and in such circumstances it is uncertain which procedure is the best surgical option for the patient. Opinion is divided regarding the relative risks and benefits of each procedure.

OBJECTIVES

To estimate the clinical effectiveness of surgical resection compared to biopsy in people with a new presumptive diagnosis of HGG.

SEARCH METHODS

We updated our searches of the following databases to 12 September 2018: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We also handsearched the Journal of Neuro-Oncology and Neuro-Oncology from 2010 to 2018 (including all conference abstracts).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving people of all ages with a presumed diagnosis of HGG based upon clinical and radiological investigation. Interventions included any form of biopsy or resection. Surgery was at the time of initial presentation and not for recurrence.

DATA COLLECTION AND ANALYSIS

Two reviews authors independently assessed the search results for relevance and undertook critical appraisal according to prespecified guidelines. Outcome measures included survival, time to progression/progression-free survival, quality of life, symptom control, adverse events, and mortality.

MAIN RESULTS

We identified a single RCT of biopsy versus resection in presumed HGG. No other articles met the inclusion criteria. Personal communication revealed that an RCT of biopsy versus resection in elderly people with HGG is underway. Further communication as part of this 2018 update revealed that the results of this study are due to be published in 2019.

AUTHORS' CONCLUSIONS

There is no high-quality evidence on biopsy versus resection for HGG that can be used to guide management. The single included RCT was of inadequate methodology to reach reliable conclusions. Further large, multicentred RCTs are required to conclusively answer the question of whether biopsy or resection is the best initial surgical management for HGG.

Improved treatment of glioblastoma - changes in survival over two decades at a single regional Centre

BACKGROUND

Glioblastoma (GBM) is an aggressive brain tumor with a short overall survival (OS) in general. The treatment of GBM has evolved over the last decades and is today multimodal including surgical resection followed by radiochemotherapy and adjuvant chemotherapy for patients in good performance status. The aim of this study was to evaluate the development of treatment and the outcome for GBM patients at a single regional center.

PATIENTS AND METHODS

Survival was studied for 571 patients in our region diagnosed with GBM between 1995 and 2015. Samples from 244 patients out of those treated 2005-2015 have been included in a tissue/blood bank and a clinical database has been set up with basic patient characteristics and details on surgery and non-surgical treatment.

RESULTS

The median OS for all patients from 1995 to 2015 was 9.3 months. There was a stepwise improvement from 6.9 to 10.3 months for patients diagnosed 1995-1996 and 2010-2015, respectively (p < .05). The 2-year survival for the same time periods improved from 7% to 18% (p < .01). After introduction of postoperative radiochemotherapy for patients in good performance status in 2005 an increased OS was noted and following implementation of intraoperative 5-aminolevulinic acid the number of tumor resection ≥95% did increase from 33% to 54% (p < .001). Positive prognostic factors for survival were young age, good performance status, absence of inflammatory disease, absence of diabetes or metabolic disease, tumor resection ≥95%, and completion of postoperative radiochemotherapy.

DISCUSSION

The results of this study are consistent with earlier results regarding survival and prognostic factors and confirm results from randomized controlled trials in a clinical setting. Despite the improvements made, the prognosis is still dismal and the need for further research on GBM treatment is great.

Biodegradable interstitial release polymer loading a novel small molecule targeting Axl receptor tyrosine kinase and reducing brain tumour migration and invasion

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumour. The neoplasms are difficult to resect entirely because of their highly infiltration property and leading to the tumour edge is unclear. Gliadel wafer has been used as an intracerebral drug delivery system to eliminate the residual tumour. However, because of its local low concentration and short diffusion distance, patient survival improves non-significantly. Axl is an essential regulator in cancer metastasis and patient survival. In this study, we developed a controlled-release polyanhydride polymer loading a novel small molecule, n-butylidenephthalide (BP), which is not only increasing local drug concentration and extending its diffusion distance but also reducing tumour invasion, mediated by reducing Axl expression. First, we determined that BP inhibited the expression of Axl in a dose- and time-dependent manner and reduced the migratory and invasive capabilities of GBM cells. In addition, BP downregulated matrix metalloproteinase activity, which is involved in cancer cell invasion. Furthermore, we demonstrated that BP regulated Axl via the extracellular signal-regulated kinases pathway. Epithelial-to-mesenchymal transition (EMT) is related to epithelial cells in the invasive migratory mesenchymal cells that underlie cancer progression; we demonstrated that BP reduced the expression of EMT-related genes. Furthermore, we used the overexpression of Axl in GBM cells to prove that Axl is a crucial target in the inhibition of GBM EMT, migration and invasion. In an in vivo study, we demonstrated that BP inhibited tumour growth and suppressed Axl expression in a dose-dependent manner according to a subcutaneous tumour model. Most importantly, in an intracranial tumour model with BP wafer in situ treatment, we demonstrated that the BP wafer not only significantly increased the survival rate but also decreased Axl expression, and inhibited tumour invasion. These results contribute to the development of a BP wafer for a novel therapeutic strategy for treating GBM invasion and increasing survival in clinical subjects.

Clinical management of grade III oligodendroglioma

Oligodendrogliomas represent the third most common type of glioma, comprising 4%-15% of all gliomas and can be classified by degree of malignancy into grade II and grade III, according to WHO classification. Only 30% of oligodendroglial tumors have anaplastic characteristics. Anaplastic oligodendroglioma (AO) is often localized as a single lesion in the white matter and in the cortex, rarely in brainstem or spinal cord. The management of AO is deeply changed in the recent years. Maximal safe surgical resection followed by radiotherapy (RT) was considered as the standard of care since paramount findings regarding molecular aspects, in particular co-deletion of the short arm of chromosome 1 and the long arm of chromosome 19, revealed that these subsets of AO, benefit in terms of overall survival (OS) and progression-free survival (PFS), from the addition of chemotherapy to RT. Allelic losses of chromosomes 1p and 19q occur in 50%-70% of both low-grade and anaplastic tumors, representing a strong prognostic factor and a powerful predictor of prolonged survival. Several other molecular markers have potential clinical significance as IDH1 mutations, confirming the strong prognostic role for OS. Malignant brain tumors negatively impacts on patients' quality of life. Seizures, visual impairment, headache, and cognitive disorders can be present. Moreover, chemotherapy and RT have important side effects. For these reasons, "health-related quality of life" is becoming a topic of growing interest, investigating on physical, mental, emotional, and social well-being. Understanding the impact of medical treatment on health-related quality of life will probably have a growing effect both on health care strategies and on patients.

Biopsy versus partial versus gross total resection in older patients with high-grade glioma: a systematic review and meta-analysis

BACKGROUND

Optimal extent of surgical resection (EOR) of high-grade gliomas (HGGs) remains uncertain in the elderly given the unclear benefits and potentially higher rates of mortality and morbidity associated with more extensive degrees of resection.

METHODS

We undertook a meta-analysis according to a predefined protocol and systematically searched literature databases for reports about HGG EOR. Elderly patients (≥60 y) undergoing biopsy, subtotal resection (STR), and gross total resection (GTR) were compared for the outcome measures of overall survival (OS), postoperative karnofsky performance status (KPS), progression-free survival (PFS), mortality, and morbidity. Treatment effects as pooled estimates, mean differences (MDs), or risk ratios (RRs) with corresponding 95% confidence intervals (CIs) were determined using random effects modeling.

RESULTS

A total of 12 607 participants from 34 studies met eligibility criteria, including our current cohort of 211 patients. When comparing overall resection (of any extent) with biopsy, in favor of the resection group were OS (MD 3.88 mo, 95% CI: 2.14-5.62, P < .001), postoperative KPS (MD 10.4, 95% CI: 6.58-14.22, P < .001), PFS (MD 2.44 mo, 95% CI: 1.45-3.43, P < .001), mortality (RR = 0.27, 95% CI: 0.12-0.61, P = .002), and morbidity (RR = 0.82, 95% CI: 0.46-1.46, P = .514) . GTR was significantly superior to STR in terms of OS (MD 3.77 mo, 95% CI: 2.26-5.29, P < .001), postoperative KPS (MD 4.91, 95% CI: 0.91-8.92, P = .016), and PFS (MD 2.21 mo, 95% CI: 1.13-3.3, P < .001) with no difference in mortality (RR = 0.53, 95% CI: 0.05-5.71, P = .600) or morbidity (RR = 0.52, 95% CI: 0.18-1.49, P = .223).

CONCLUSIONS

Our findings suggest an upward improvement in survival time, functional recovery, and tumor recurrence rate associated with increasing extents of safe resection. These benefits did not result in higher rates of mortality or morbidity if considered in conjunction with known established safety measures when managing elderly patients harboring HGGs.

Anaplastic oligodendroglioma: a new treatment paradigm and current controversies

OPINION STATEMENT

Anaplastic oligodendroglial tumors have gained increasing interest with the emerging role of molecular markers and systemic chemotherapy during the past years. The long-term results of two landmark trials, RTOG 9402 and EORTC 26961, have resulted in a reconsideration of the appropriate therapeutic approaches for patients with these tumors. Both trials indicate that patients whose tumors harbor a 1p/19q co-deletion benefit particularly from the addition of procarbazine/lomustine (CCNU)/vincristine (PCV) chemotherapy to radiation therapy (RT). The median survival of patients with co-deleted tumors treated within the RTOG trial with PCV before irradiation was 14.7 years compared with 7.3 years of patients who received RT alone. Median overall survival has not been reached in the RT plus PCV arm of the EORTC trial, but a similar difference can be anticipated after a follow-up of more than 12 years. In contrast, no such benefit was observed for patients with tumors lacking 1p/19q co-deletion. Outside clinical trials, patients with anaplastic oligodendroglial tumors, and 1p/19q co-deletion therefore should be offered a combined treatment modality regimen, including radio- and chemotherapy. PCV, however, is associated with significant hematological toxicity and also nonhematological side effects, which probably translate into reduced quality of life for long-term survivors. Therefore, it might be warranted to replace PCV by temozolomide, which displays a more favorable side effect profile. Data from the NOA-04 study suggest that PCV and temozolomide have similar effects. However, long-term data on the benefit from temozolomide are lacking, making a definite answer on the equivalence of temozolomide and PCV in anaplastic oligodendroglioma (AO) impossible. The current evidence precludes RT alone for AO patients. Neither the RTOG nor the EORTC trial defined the role of chemotherapy alone. A comparison of combined modality treatment with chemotherapy alone followed by RT at progression is pending. Long-term follow-up of NOA-04 patients and results from future trials may help to clarify these questions. With more and more AO patients living 10 years or more, particular attention must be paid to late side effects, such as neurotoxicity, and careful monitoring is required for all treated patients.

Methodology and reporting of meta-analyses in the neurosurgical literature

OBJECT

Neurosurgeons are inundated with vast amounts of new clinical research on a daily basis, making it difficult and time-consuming to keep up with the latest literature. Meta-analysis is an extension of a systematic review that employs statistical techniques to pool the data from the literature in order to calculate a cumulative effect size. This is done to answer a clearly defined a priori question. Despite their increasing popularity in the neurosurgery literature, meta-analyses have not been scrutinized in terms of reporting and methodology.

METHODS

The authors performed a literature search using PubMed/MEDLINE to locate all meta-analyses that have been published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Accepted checklists for reporting (PRISMA) and methodology (AMSTAR) were applied to each meta-analysis, and the number of items within each checklist that were satisfactorily fulfilled was recorded. The authors sought to answer 4 specific questions: Are meta-analyses improving 1) with time; 2) when the study met their definition of a meta-analysis; 3) when clinicians collaborated with a potential expert in meta-analysis; and 4) when the meta-analysis was the only focus of the paper?

RESULTS

Seventy-two meta-analyses were published in the JNS Publishing Group journals and Neurosurgery between 1990 and 2012. The number of published meta-analyses has increased dramatically in the last several years. The most common topics were vascular, and most were based on observational studies. Only 11 papers were prepared using an established checklist. The average AMSTAR and PRISMA scores (proportion of items satisfactorily fulfilled divided by the total number of eligible items in the respective instrument) were 31% and 55%, respectively. Major deficiencies were identified, including the lack of a comprehensive search strategy, study selection and data extraction, assessment of heterogeneity, publication bias, and study quality. Almost one-third of the papers did not meet our basic definition of a meta-analysis. The quality of reporting and methodology was better 1) when the study met our definition of a meta-analysis; 2) when one or more of the authors had experience or expertise in conducting a meta-analysis; 3) when the meta-analysis was not conducted alongside an evaluation of the authors' own data; and 4) in more recent studies.

CONCLUSIONS

Reporting and methodology of meta-analyses in the neurosurgery literature is excessively variable and overall poor. As these papers are being published with increasing frequency, neurosurgical journals need to adopt a clear definition of a meta-analysis and insist that they be created using checklists for both reporting and methodology. Standardization will ensure high-quality publications.

The treatment of glioblastomas: a systematic update on clinical Phase III trials

Glioblastomas (GBMs) are invariably associated with unavoidable tumor recurrence and overall poor prognosis. The present study is to summarize the results of clinical Phase III studies on GBMs over the past seven years. A systematic literature search was performed using major electronic databases and by screening meeting abstracts. Totally, 16 studies of patients with newly diagnosed GBMs, recurrent GBMs, and elderly patients with GBMs were selected for this review. Although the outcomes of the experimental therapies were not encouraging, these studies produced a considerable amount of potentially clinically relevant information. Such aspects as surgical outcomes, radiation schedules, temozolomide (TMZ) schedules, methylation status of the O6-methylguanine DNA methyltransferase (MGMT) gene, combination of therapies, novel drug delivery methods and use of targeted agents have come to light and are being addressed here. In addition, we discuss the existing controversies of (1) surgical studies, (2) evaluations of recurrence, (3) salvage treatment bias, and (4) studies on elderly patients.

[First intraoperative magnetic resonance imaging in a Spanish hospital of the public healthcare system: initial experience, feasibility and difficulties in our environment]

OBJECTIVE

Intraoperative MRI is considered the gold standard among all intraoperative imaging technologies currently available. Its main indication is in the intraoperative detection of residual disease during tumour resections. We present our initial experience with the first intraoperative low-field MRI in a Spanish hospital of the public healthcare system. We evaluate its usefulness and accuracy to detect residual tumours and compare its intraoperative results with images obtained postoperatively using conventional high-field devices.

MATERIAL AND METHODS

We retrospectively reviewed the first 21 patients operated on the aid of this technology. Maximal safe resection was the surgical goal in all cases. Surgeries were performed using conventional instrumentation and the required assistance in each case.

RESULTS

The mean number of intraoperative studies was 2.3 per procedure (range: 2 to 4). Intraoperative studies proved that the surgical goal had been achieved in 15 patients (71.4%), and detected residual tumour in 6 cases (28.5%). After comparing the last intraoperative image and the postoperative study, 2 cases (9.5%) were considered as "false negatives".

CONCLUSIONS

Intraoperative MRI is a safe, reliable and useful tool for guided resection of brain tumours. Low-field devices provide images of sufficient quality at a lower cost; therefore their universalisation seems feasible.

Anaplastic gliomas: radiation, chemotherapy, or both?

The optimal treatment of anaplastic gliomas is controversial. Options for treatment include radiation, chemotherapy or a combination of modalities. This article describes how treatment algorithms for anaplastic gliomas have evolved and interprets the results of recent studies. The available evidence indicates that patients can be treated with either chemotherapy or radiation as initial therapy, with use of the other treatment modality at relapse. Whether subpopulations exist for whom one treatment modality is superior to the other at initial diagnosis must be studied prospectively.

Intraoperative image guidance in neurosurgery: development, current indications, and future trends

Introduction. As minimally invasive surgery becomes the standard of care in neurosurgery, it is imperative that surgeons become skilled in the use of image-guided techniques. The development of image-guided neurosurgery represents a substantial improvement in the microsurgical treatment of tumors, vascular malformations, and other intracranial lesions. Objective. There have been numerous advances in neurosurgery which have aided the neurosurgeon to achieve accurate removal of pathological tissue with minimal disruption of surrounding healthy neuronal matter including the development of microsurgical, endoscopic, and endovascular techniques. Neuronavigation systems and intraoperative imaging should improve success in cranial neurosurgery. Additional functional imaging modalities such as PET, SPECT, DTI (for fiber tracking), and fMRI can now be used in order to reduce neurological deficits resulting from surgery; however the positive long-term effect remains questionable for many indications. Method. PubMed database search using the search term "image guided neurosurgery." More than 1400 articles were published during the last 25 years. The abstracts were scanned for prospective comparative trials. Results and Conclusion. 14 comparative trials are published. To date significant data amount show advantages in intraoperative accuracy influencing the perioperative morbidity and long-term outcome only for cerebral glioma surgery.

Malignant glioma grade 3 and 4: how relevant is timing of radiotherapy?

AIMS AND BACKGROUND

The aim of this study is to determine prognostic factors that influence further outcome in patients with glioma.

METHODS

Between 01/2002 and 08/2008, 153 patients with malignant gliomas of WHO-grade 3 or 4 who were treated with external beam radiotherapy with or without chemotherapy.

RESULTS

In univariate analysis, following factors were ascertained as statistically significant prognostic parameters: grade (p = 0.000), time between operation and radiotherapy >24 days (p = 0.044) for progression-free survival; grade (p = 0.000), age<58 years (p = 0.001), extent of surgery (p = 0.011), time between operation and radiotherapy >24 days (p = 0.009), overall treatment time >68 days (p = 0.003), use of chemotherapy (p = 0.015) for overall survival. A longer time period between resection and start of radiotherapy showed to be associated with improved outcome. After multivariate analysis, only grade (p = 0.000) remained a statistically significant factor for progression-free and grade (p = 0.000) and use of chemotherapy (p = 0.031) for overall survival.

CONCLUSIONS

We were able to recognize grade and use of chemotherapy as statistically significant prognostic determinants, but not time intervals or overall treatment time.

Temozolomide plus radiotherapy for glioblastoma in a Canadian province: Efficacy versus effectiveness and the impact of O6-methylguanine-DNA-methyltransferase promoter methylation

Background: Radiotherapy with concomitant and adjuvant temozolomide has been the standard of care for newly diagnosed glioblastoma in adults since the pivotal trial by Roger Stupp and colleagues. The effectiveness of this regimen has not been evaluated in Canada. Additionally, the impact of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation on patient survival has not been confirmed. Hence, survival outcomes and MGMT predictive value were compared for the patients in Alberta versus the Stupp trial population.

Methods: Retrospective chart review of 215 adult glioblastoma patients who started radiotherapy and temozolomide between January 2007 and December 2010 at the Cross Cancer Institute (Edmonton, Alberta) or the Tom Baker Cancer Centre (Calgary, Alberta).

Results: In the Alberta population, median overall survival was 14.3 months (vs. 14.6 months in trial, p = NS) and median progression-free survival was 5.8 months (vs. 6.9 months in trial, p = NS). However, unlike the trial, the Alberta MGMT subgroup analysis for overall survival was not statistically significant, despite a hazard ratio of 0.65 in favor of the methylated group. More Alberta patients received corticosteroids ( p < 0.0001) and fewer underwent complete resection ( p = 0.0001) or a postprogression second surgery ( p = 0.01) than the Stupp population, but characteristics were otherwise similar.

Conclusion: Current practice in Alberta enables patients to achieve overall and progression-free survival similar to the clinical trial. Further follow-up is required to confirm the predictive value of the MGMT assay. Until that is clarified or better treatments are developed, it is reasonable to continue offering this treatment regimen to patients regardless of MGMT methylation status.

Boron neutron capture therapy combined with fractionated photon irradiation for glioblastoma: a recursive partitioning analysis of BNCT patients

Eight patients to received Boron Neuron Capture Therapy (BNCT) were selected from 33 newly diagnosed glioblastoma patients (NCT(+) group). Serial 42 glioblastoma patients (NCT(-) group) were treated without BNCT. The median OS of the NCT(+) group and NCT (-) group were 24.4 months and 14.9 months. In the high risk patients (RPA class V), the median OS of the NCT(+) group tended to be better than that of NCT(-) group. 50% of BNCT patients were RPA class V.

Association between epidermal growth factor +61 G/A polymorphism and glioma risk in a Chinese Han population

The association between the +61 G/A polymorphism of the epidermal growth factor (EGF) gene and glioma risk remains controversial and unclear. The objective of this study was to investigate the association between the EGF +61 G/A polymorphism and glioma risk in a Chinese Han population. Peripheral blood samples were extracted from 160 glioma patients and 320 control subjects. Genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism method. Glioma patients had a significantly higher frequency of the AA genotype (odds ratio [OR] 1.93, 95% confidence intervals [CI] 1.08, 3.44) than control subjects and the frequency of the AA genotype was significantly higher in glioblastoma patients than in patients with other gliomas (OR 2.19, 95% CI 1.05, 4.57). Patients with grade IV gliomas had a significantly higher frequency of the AA genotype (OR 2.25, 95% CI 1.08, 4.71) than patients with lower grade gliomas. This study demonstrated that the EGF +61 AA genotype is associated with an increased risk of glioma in a Chinese Han population.

Biopsy versus resection for malignant glioma

BACKGROUND

Patients with isolated supratentorial brain tumours, presumed to be primary on imaging, have two surgical management options - biopsy or resection. Surgical opinions appear to be equally divided when considering the relative risks and benefits of these two procedures.

OBJECTIVES

To estimate the clinical effectiveness of radical surgical resection compared to simple biopsy in patients with malignant glioma.

SEARCH STRATEGY

Electronic database searches of COCHRANE CONTROLLED TRIALS REGISTER (including the Cochrane Cancer Network Specialised Register of Trials), MEDLINE, CANCERLIT, EMBASE, BIOSIS and SCIENCE CITATION INDEX. Hand searching the references of all identified studies; hand searching the Journal of Neuro-Oncology over the previous 10 years, including all conference abstracts; personal communication.

SELECTION CRITERIA

Randomised and clinical controlled trials were included if they compared biopsy to resection, or looked at effect of extent of resection on survival, time to progression or quality of life, for malignant glioma patients of all ages.

DATA COLLECTION AND ANALYSIS

Studies were to be identified, critically appraised and data extracted by the author (SEM). For dichotomous data, Peto odds ratios (OR) with 95% confidence intervals (CI) were hoped to have been estimated. Normal continuous data were to have been summated using the weighted mean difference (WMD).

MAIN RESULTS

The electronic database search yielded 2100 citations. Of these, two articles were identified for possible inclusion, however both were excluded. The hand search and personal communication were similarly unproductive. No studies were included in the review and no data was synthesised.

REVIEWER'S CONCLUSIONS

Given that no qualifying studies were identified and because this is an important issue, both in terms of patient risk and benefit and health economics, the author feels it important to conduct a randomised controlled trial in this subject.