Racial Disparities in Outcomes After Spine Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: Racial disparities are a major issue in health care but the overall extent of the issue in spinal surgery outcomes is unclear. We conducted a systematic review/meta-analysis of disparities in outcomes among patients belonging to different racial groups who had undergone surgery for degenerative spine disease. METHODS: We searched Ovid MEDLINE, Scopus, Cochrane Review Database, and ClinicalTrials.gov from inception to January 20, 2021 for relevant articles assessing outcomes after spine surgery stratified by race. We included studies that compared outcomes after spine surgery for degenerative disease among different racial groups. RESULTS: We found 30 studies that met our inclusion criteria (28 articles and 2 published abstracts). We included data from 20 cohort studies in our meta-analysis (3,501,830 patients), which were assessed to have a high risk of observation/selection bias. Black patients had a 55% higher risk of dying after spine surgery compared with white patients (relative risk [RR], 1.55, 95% confidence interval [CI], 1.28-1.87; I2 = 70%). Similarly, black patients had a longer length of stay (mean difference, 0.93 days; 95% CI, 0.75-1.10; I2 = 73%), and higher risk of nonhome discharge (RR, 1.63; 95% CI, 1.47-1.81; I2 = 89%), and 30-day readmission (RR, 1.45; 95% CI, 1.03-2.04; I2 = 96%). No significant difference was noted in the pooled analyses for complication or reoperation rates. CONCLUSIONS: Black patients have a significantly higher risk of unfavorable outcomes after spine surgery compared with white patients. Further work in understanding the reasons for these disparities will help develop strategies to narrow the gap among the racial groups.

Improving the Usability of 5-Aminolevulinic Acid Fluorescence-Guided Surgery by Adding an Optimized Secondary Light Source.

BACKGROUND: Tumors that take up and metabolize 5-aminolevulinic acid emit bright pink fluorescence when illuminated with blue light, aiding surgeons in identifying the margin of resection. The adoption of this method is hindered by the blue light illumination, which is too dim to safely operate under and therefore necessitates switching back and forth from white-light mode. The aim of this study was to examine the addition of an optimized secondary illuminant adapter to improve usability of blue-light mode without degrading tumor contrast. METHODS: Color science methods were used to evaluate the color of the secondary illuminant and its impact on color rendering index as well as the tumor-to-background color contrast in data collected from 7 patients with high-grade gliomas (World Health Organization grade III and IV). A secondary illuminant adapter was built to provide 475-600 nm light the intensity of which can be controlled by the surgeon and was evaluated in 2 additional patients. RESULTS: Secondary illuminant color had opposing effects on color rendering index and tumor-to-background color contrast; providing surgeon control of intensity allows this trade-off to be balanced in real time. Demonstration in 2 high-grade glioma cases confirms this, showing that additional visibility adds value when intensity can be controlled by the surgeon. CONCLUSIONS: Addition of a secondary illuminant may mitigate surgeon complaints that the operative field is too dark under the blue light illumination required for 5-aminolevulinic acid fluorescence guidance by providing improved color rendering index without completely sacrificing tumor-to-background color contrast.

Congress of neurological surgeons systematic review and evidence-based clinical practice parameter guidelines for the treatment of adults with newly diagnosed glioblastoma: Introduction and Methods.

PURPOSE: This is an update of the evidence-based guideline for management of newly diagnosed glioblastomas sponsored by the American Association of Neurological Surgeons (AANS) and Congress of Neurological Surgeons (CNS) initially published in 2008. The objective is to update evidence-based management of newly diagnosed glioblastomas over all commonly used diagnostic and treatment modalities in regularly encountered clinical situations. METHODS: A multidisciplinary writing group was assembled to create documents related to imaging, cytoreductive surgery, neuropathology, radiation therapy, chemotherapy and emerging developments. Questions from the prior set of guidelines, and new and modified questions were used to guide a search of the scientific literature since the last guideline search was completed in June 2005. Citations were screened, classified and used as evidence to create recommendations addressing the questions in a manner that was directly linked to this evidence. RESULTS: The sixteen writers produced 34 questions resulting in eight Level I recommendations, eleven Level II recommendations, and 27 Level II recommendations across all the topics. In some instances, insufficient data was available to answer all or part of a question and this is stated and explained. CONCLUSIONS: This series of guidelines is based upon relevant evidence in the literature related to the management of newly diagnosed glioblastomas. They set a benchmark for the management of this disease while highlighting key areas of weakness in our knowledge and suggest directions for future basic and clinical research to improve evidence quality and recommendation strength.

Cytoreductive surgery in the management of newly diagnosed glioblastoma in adults: a systematic review and evidence-based clinical practice guideline update.

TARGET POPULATION: These recommendations apply to adults with newly diagnosed or suspected glioblastoma. QUESTION: What is the effect of extent of surgical resection on patient outcome in the initial management of adult patients with suspected newly diagnosed glioblastoma? RECOMMENDATION: Level II: Maximal cytoreductive surgery is recommended in adult patients with suspected newly diagnosed supratentorial glioblastoma with gross total resection defined as removal of contrast enhancing tumor. Level III: Biopsy, subtotal resection, or gross total resection is suggested depending on medical comorbidities, functional status, and location of tumor if maximal resection may cause significant neurologic deficit. QUESTION: What is the role of cytoreductive surgery in adults with newly diagnosed bi-frontal "butterfly" glioblastoma? RECOMMENDATION: Level III: Resection of newly diagnosed bi-frontal "butterfly" glioblastoma is suggested to improve overall survival over biopsy alone. QUESTION: What is the goal of cytoreductive surgery in elderly adult patients with newly diagnosed glioblastoma? RECOMMENDATION: Level III: Elderly patients (> 65 years) show survival benefit with gross total resection and it is suggested they undergo cytoreductive surgery. QUESTION: What is the role of advanced intraoperative guidance techniques in cytoreductive surgery in adults with newly diagnosed glioblastoma? RECOMMENDATION: Level III: The use of intraoperative guidance adjuncts such as intraoperative MRI (iMRI) or 5-aminolevulinic acid (5-ALA) are suggested to maximize extent of resection in newly diagnosed glioblastoma. There is insufficient evidence to make a suggestion on the use of fluorescein, indocyanine green, or intraoperative ultrasound.

The role of neuropathology in the management of newly diagnosed glioblastoma: a systematic review and evidence-based clinical practice guideline.

TARGET POPULATION: These recommendations apply to adult patients with newly diagnosed or suspected glioblastoma (GBM) QUESTION : For adult patients with newly diagnosed GBM does testing for Isocitrate Dehydrogenase 1 or 2 (IDH 1/2) mutations afford benefit beyond standard histopathology in providing accurate classification and outcome prognostication? Level III IDH 1/2 mutational status by immunohistochemistry (IHC) and/or sequencing is suggested for classification and prognostic information. Level III Non-canonical IDH 1/2 mutations are very rare in patients aged 55 or older and universal testing of variant mutations by sequence analysis is not suggested for this age range. QUESTION: For adult patients with lower grade infiltrating astrocytomas (WHO grades II and III) can the IDH-wildtype status designation supersede histopathology to predict prognosis and biologic relevance to eventual behavior as a GBM? Level III The designation of infiltrating astrocytomas (WHO grades II and III) as IDH-wildtype is not suggested as sufficient for a higher grade designation alone. Level III It is suggested that IDH-wildtype WHO grades II and III astrocytomas be tested for molecular-genetic alterations typical of IDH-wildtype GBM such as EGFR amplification, gain of chromosome 7/loss of chromosome 10 and TERT-p mutation to substantiate prediction of behavior similar to IDH-wildtype glioblastoma. Level III It is suggested that a diagnosis of diffuse astrocytic glioma, IDH-wildtype, with molecular features of GBM, WHO grade IV be rendered for infiltrating astrocytomas that lack histologic criteria of GBM but harbors molecular-genetic alterations of IDH-wildtype glioblastoma. QUESTION: For adult patients with newly diagnosed infiltrating glioma arising in the midline does testing for H3-K27M mutations provide information beyond that gained by histopathology for accurate classification and outcome prognostication? Level III It is suggested that infiltrating gliomas arising in midline anatomic locations be tested for the H3-K27M mutation as they tend to exhibit WHO grade IV behavior even if they lack histologic criteria for glioblastoma.

Determining an Appropriate Outcome Measure in Neurosurgical Research: Investigating Meaningful, Valid, and Practical Metrics.

Given the rapidly evolving pace of research and technology in the neurosurgical field, it is critical to consider the parameters of valid, practical, and meaningful study outcome measures. Here we review fundamental aspects of selecting outcome measures in the context of neurosurgical research. Exemplifying work in meningiomas and high-grade gliomas, we delineate a proposed framework for identifying an appropriate outcome measure. Four fundamental components of an outcome measure are defined and characterized: understanding characteristics of a good outcome measure; developing a research question to address an outcome measure; defining the outcome measure, and considering limitations of an outcome measure. This four-part framework enhances and promotes the methodology for determining if an outcome measure is valid, practical, and ultimately meaningful.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Steroids in the Treatment of Adults With Metastatic Brain Tumors.

QUESTION: Do steroids improve neurological symptoms and/or quality of life in patients with metastatic brain tumors compared to supportive care only or other treatment options? If steroids are given, what dose should be used? TARGET POPULATION: These recommendations apply to adults diagnosed with brain metastases. RECOMMENDATIONS: STEROID THERAPY VERSUS NO STEROID THERAPYAsymptomatic brain metastases patients without mass effectInsufficient evidence exists to make a treatment recommendation for this clinical scenario.Brain metastases patients with mild symptoms related to mass effect Level 3: Corticosteroids are recommended to provide temporary symptomatic relief of symptoms related to increased intracranial pressure and edema secondary to brain metastases. It is recommended for patients who are symptomatic from metastatic disease to the brain that a starting dose of 4 to 8 mg/d of dexamethasone be considered.Brain metastases patients with moderate to severe symptoms related to mass effect Level 3: Corticosteroids are recommended to provide temporary symptomatic relief of symptoms related to increased intracranial pressure and edema secondary to brain metastases. If patients exhibit severe symptoms consistent with increased intracranial pressure, it is recommended that higher doses such as 16 mg/d or more be considered. CHOICE OF STEROID: Level 3: If corticosteroids are given, dexamethasone is the best drug choice given the available evidence.Duration of Corticosteroid Administration Level 3: Corticosteroids, if given, should be tapered as rapidly as possible but no faster than clinically tolerated, based upon an individualized treatment regimen and a full understanding of the long-term sequelae of corticosteroid therapy.Given the very limited number of studies (2) which met the eligibility criteria for the systematic review, these are the only recommendations that can be offered based on this methodology.The full guideline can be found at https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_7.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for the Treatment of Adults With Metastatic Brain Tumors: Executive Summary.

BACKGROUND: The Congress of Neurological Surgeons systematic review and evidence-based clinical practice parameter guidelines for the treatment of adults with metastatic brain tumors was first published in 2010. Because of the time elapsed since that publication, an update of this set of guidelines based on literature published since is now indicated. OBJECTIVE: To establish the best evidence-based management of metastatic brain tumors over all commonly used diagnostic and treatment modalities in regularly encountered clinical situations. METHODS: Literature searches regarding management of metastatic brain tumors with whole brain radiation therapy, surgery, stereotactic radiosurgery, chemotherapy, prophylactic anticonvulsants, steroids, instances of multiple brain metastases, and emerging and investigational therapies were carried out to answer questions designed by consensus of a multidisciplinary writing group. RESULTS: Recommendations were created and their strength linked to the quality of the literature data available thus creating an evidence-based guideline. Importantly, shortcomings and biases to the literature data are brought out so as to provide guidance for future investigation and improvements in the management of patients with metastatic brain tumors. CONCLUSION: This series of guidelines was constructed to assess the most current and clinically relevant evidence for management of metastatic brain tumors. They set a benchmark regarding the current evidence base for this management while also highlighting important key areas for future basic and clinical research, particularly on those topics for which no recommendations could be formulated.The full guideline can be found at: https://www.cns.org/guidelines-treatment-adults-metastatic-brain-tumors/chapter_1.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Surgery in the Management of Adults With Metastatic Brain Tumors.

Please see the full-text version of this guideline https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_2) for the target population of each recommendation listed below. SURGERY FOR METASTATIC BRAIN TUMORS AT NEW DIAGNOSIS QUESTION: Should patients with newly diagnosed metastatic brain tumors undergo surgery, stereotactic radiosurgery (SRS), or whole brain radiotherapy (WBRT)? RECOMMENDATIONS: Level 1: Surgery + WBRT is recommended as first-line treatment in patients with single brain metastases with favorable performance status and limited extracranial disease to extend overall survival, median survival, and local control. Level 3: Surgery plus SRS is recommended to provide survival benefit in patients with metastatic brain tumors Level 3: Multimodal treatments including either surgery + WBRT + SRS boost or surgery + WBRT are recommended as alternatives to WBRT + SRS in terms of providing overall survival and local control benefits. SURGERY AND RADIATION FOR METASTATIC BRAIN TUMORS QUESTION: Should patients with newly diagnosed metastatic brain tumors undergo surgical resection followed by WBRT, SRS, or another combination of these modalities? RECOMMENDATIONS: Level 1: Surgery + WBRT is recommended as superior treatment to WBRT alone in patients with single brain metastases. Level 3: Surgery + SRS is recommended as an alternative to treatment with SRS alone to benefit overall survival. Level 3: It is recommended that SRS alone be considered equivalent to surgery + WBRT. SURGERY FOR RECURRENT METASTATIC BRAIN TUMORS QUESTION: Should patients with recurrent metastatic brain tumors undergo surgical resection? RECOMMENDATIONS: Level 3: Craniotomy is recommended as a treatment for intracranial recurrence after initial surgery or SRS. SURGICAL TECHNIQUE AND RECURRENCE QUESTION A: Does the surgical technique (en bloc resection or piecemeal resection) affect recurrence? RECOMMENDATION: Level 3: En bloc tumor resection, as opposed to piecemeal resection, is recommended to decrease the risk of postoperative leptomeningeal disease when resecting single brain metastases. QUESTION B: Does the extent of surgical resection (gross total resection or subtotal resection) affect recurrence? RECOMMENDATION: Level 3: Gross total resection is recommended over subtotal resection in recursive partitioning analysis class I patients to improve overall survival and prolong time to recurrence. The full guideline can be found at https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_2.

CD271+ Cells Are Diagnostic and Prognostic and Exhibit Elevated MAPK Activity in SHH Medulloblastoma.

The extensive heterogeneity both between and within the medulloblastoma subgroups underscores a critical need for variant-specific biomarkers and therapeutic strategies. We previously identified a role for the CD271/p75 neurotrophin receptor (p75NTR) in regulating stem/progenitor cells in the SHH medulloblastoma subgroup. Here, we demonstrate the utility of CD271 as a novel diagnostic and prognostic marker for SHH medulloblastoma using IHC analysis and transcriptome data across 763 primary tumors. RNA sequencing of CD271+ and CD271- cells revealed molecularly distinct, coexisting cellular subsets, both in vitro and in vivo MAPK/ERK signaling was upregulated in the CD271+ population, and inhibiting this pathway reduced endogenous CD271 levels, stem/progenitor cell proliferation, and cell survival as well as cell migration in vitro Treatment with the MEK inhibitor selumetinib extended survival and reduced CD271 levels in vivo, whereas, treatment with vismodegib, a well-known smoothened (SMO) inhibitor currently in clinical trials for the treatment of recurrent SHH medulloblastoma, had no significant effect in our models. Our study demonstrates the clinical utility of CD271 as both a diagnostic and prognostic tool for SHH medulloblastoma tumors and reveals a novel role for MEK inhibitors in targeting CD271+ SHH medulloblastoma cells.Significance: This study identifies CD271 as a specific and novel biomarker of SHH-type medulloblastoma and that targeting CD271+ cells through MEK inhibition represents a novel therapeutic strategy for the treatment of SHH medulloblastoma. Cancer Res; 78(16); 4745-59. ©2018 AACR.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Treatment of Adults With Vestibular Schwannomas: Executive Summary.

BACKGROUND: Vestibular schwannomas (VS) are uncommon lesions that are a substantial challenge to the neurosurgeons, otologists, and radiation oncologists who undertake their clinical management. A starting point to improving the current knowledge is to define the benchmarks of the current research studying VS management using evidence-based techniques in order to allow meaningful points of departure for future scientific and clinical research. OBJECTIVE: To establish the best evidence-based management of VS, including initial otologic evaluation, imaging diagnosis, use of surgical techniques, assessment of tumor pathology, and the administration of radiation therapy. METHODS: Multidisciplinary writing groups were identified to design questions, literature searches, and collection and classification of relevant findings. This information was then translated to recommendations based on the strength of the available literature. RESULTS: This guideline series yielded some level 2 recommendations and a greater number of level 3 recommendations directed at the management of VS. Importantly, in some cases, a number of well-designed questions and subsequent searches did not yield information that allowed creation of a meaningful and justifiable recommendation. CONCLUSION: This series of guidelines was constructed to assess the most current and clinically relevant evidence for the management of VS. They set a benchmark regarding the current evidence base for this type of tumor while also highlighting important key areas for future basic and clinical research, particularly on those topics for which no recommendations could be formulated. The full guidelines can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma.

Pharmacological Inhibition of the Protein Kinase MRK/ZAK Radiosensitizes Medulloblastoma.

Medulloblastoma is a cerebellar tumor and the most common pediatric brain malignancy. Radiotherapy is part of the standard care for this tumor, but its effectiveness is accompanied by significant neurocognitive sequelae due to the deleterious effects of radiation on the developing brain. We have previously shown that the protein kinase MRK/ZAK protects tumor cells from radiation-induced cell death by regulating cell-cycle arrest after ionizing radiation. Here, we show that siRNA-mediated MRK depletion sensitizes medulloblastoma primary cells to radiation. We have, therefore, designed and tested a specific small molecule inhibitor of MRK, M443, which binds to MRK in an irreversible fashion and inhibits its activity. We found that M443 strongly radiosensitizes UW228 medulloblastoma cells as well as UI226 patient-derived primary cells, whereas it does not affect the response to radiation of normal brain cells. M443 also inhibits radiation-induced activation of both p38 and Chk2, two proteins that act downstream of MRK and are involved in DNA damage-induced cell-cycle arrest. Importantly, in an animal model of medulloblastoma that employs orthotopic implantation of primary patient-derived UI226 cells in nude mice, M443 in combination with radiation achieved a synergistic increase in survival. We hypothesize that combining radiotherapy with M443 will allow us to lower the radiation dose while maintaining therapeutic efficacy, thereby minimizing radiation-induced side effects. Mol Cancer Ther; 15(8); 1799-808. ©2016 AACR.

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

QUESTION: What is the optimal role of biopsy in the initial management of presumptive low-grade glioma in adults? TARGET POPULATION: Adult patients with imaging suggestive of a low-grade glioma. LEVEL III: Stereotactic biopsy is recommended when definitive surgical resection is limited by lesions that are deep-seated, not resectable, and/or located within eloquent cortex, or in patients unable to undergo craniotomy due to medical co-morbidities to obtain the critical tissue diagnosis needed for targeted treatment planning for patients with low-grade gliomas. QUESTION: What is the best technique for brain biopsy? TARGET POPULATION: Adult patients with imaging suggestive of a low-grade glioma. LEVEL III: Frameless and frame-based stereotactic brain biopsy for low-grade gliomas are recommended based on clinical circumstances as they provide similar diagnostic yield, diagnostic accuracy, morbidity, and mortality. It is recommended the surgeon consider advanced imaging techniques (e.g., perfusion, spectroscopy, metabolic studies) to target specific regions of interest to potentially improve diagnostic accuracy.

The role of emerging therapy in the management of patients with diffuse low grade glioma.

QUESTION: What is the role of immunotherapy/tumor vaccines in the treatment of low grade gliomas? TARGET POPULATION: Adult patients with newly diagnosed WHO grade 2 astrocytoma, oligo-astroctyoma, or oligodendroglioma. RECOMMENDATIONS: There is no evidence to support a recommendation in regards to the efficacy of immunotherapy or tumor vaccines for the treatment of low grade gliomas. It is recommended that patients be enrolled in properly designed clinical trials to assess immunotherapies and tumor vaccines for low grade gliomas. QUESTION: What is the role of nutrition in the treatment of low grade gliomas? TARGET POPULATION: Adult patients with newly diagnosed WHO grade 2 astrocytoma, oligo-astroctyoma, or oligodendroglioma. RECOMMENDATIONS: There was no evidence to support a recommendation in regard to the efficacy of nutritional therapy for the treatment of low grade gliomas. It is recommended that patients be enrolled in properly designed clinical trials to assess the efficacy of nutrition for this target population. QUESTION: Is there a role for alternative or targeted therapies in the treatment of low grade gliomas? TARGET POPULATION: Adult patients with newly diagnosed WHO grade 2 astrocytoma, oligo-astroctyoma, or oligodendroglioma. RECOMMENDATION: There was no evidence to support a recommendation in regard to the efficacy of targeted or alternative agents for the treatment of low grade gliomas. It is recommended that patients be enrolled in properly designed clinical trials to assess alternative and targeted therapies for this target population.

The role of initial chemotherapy for the treatment of adults with diffuse low grade glioma : A systematic review and evidence-based clinical practice guideline.

TARGET POPULATION: Adult patients (older than 18 years of age) with newly diagnosed World Health Organization (WHO) Grade II gliomas (Oligodendroglioma, astrocytoma, mixed oligoastrocytoma). QUESTION: Is there a role for chemotherapy as adjuvant therapy of choice in treatment of patients with newly diagnosed low-grade gliomas? LEVEL III: Chemotherapy is recommended as a treatment option to postpone the use of radiotherapy, to slow tumor growth and to improve progression free survival (PFS), overall survival (OS) and clinical symptoms in adult patients with newly diagnosed LGG. QUESTION: Who are the patients with newly diagnosed LGG that would benefit the most from chemotherapy? LEVEL III: Chemotherapy is recommended as an optional component alone or in combination with radiation as the initial adjuvant therapy for all patients who cannot undergo gross total resection (GTR) of a newly diagnosed LGG. Patient with residual tumor >1 cm on post-operative MRI, presenting diameter of >4 cm or older than 40 years of age should be considered for adjuvant therapy as well. QUESTION: Are there tumor markers that can predict which patients can benefit the most from initial treatment with chemotherapy? LEVEL III: The addition of chemotherapy to standard RT is recommended in LGG patients that carry IDH mutation. In addition, temozolomide (TMZ) is recommended as a treatment option to slow tumor growth in patients who harbor the 1p/19q co-deletion. QUESTION: How soon should the chemotherapy be started once the diagnosis of LGG is confirmed? RECOMMENDATION: There is insufficient evidence to make a definitive recommendation on the timing of starting chemotherapy after surgical/pathological diagnosis of LGG has been made. However, using the 12 weeks mark as the latest timeframe to start adjuvant chemotherapy is suggested. It is recommended that patients be enrolled in properly designed clinical trials to assess the timing of chemotherapy initiation once diagnosis is confirmed for this target population. QUESTION: What chemotherapeutic agents should be used for treatment of newly diagnosed LGG? RECOMMENDATION: There is insufficient evidence to make a recommendation of one particular regimen. Enrollment of subjects in properly designed trials comparing the efficacy of these or other agents is recommended so as to determine which of these regimens is superior. QUESTION: What is the optimal duration and dosing of chemotherapy as initial treatment for LGG? RECOMMENDATION: Insufficient evidence exists regarding the duration of any specific cytotoxic drug regimen for treatment of newly diagnosed LGG. Enrollment of subjects in properly designed clinical investigations assessing the optimal duration of this therapy is recommended. QUESTION: Should chemotherapy be given alone or in conjunction with RT as initial therapy for LGG? RECOMMENDATION: Insufficient evidence exists to make recommendations in this regard. Hence, enrollment of patients in properly designed clinical trials assessing the difference between chemotherapy alone, RT alone or a combination of them is recommended. QUESTION: Should chemotherapy be given in addition to other type of adjuvant therapy to patients with newly diagnosed LGG? RECOMMENDATION: Level II: It is recommended that chemotherapy be added to the RT in patients with unfavorable LGG to improve their progression free survival.

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

TARGET POPULATION: Adult patients (age ≥18 years) who have suspected low-grade diffuse glioma. QUESTION: What are the optimal neuropathological techniques to diagnose low-grade diffuse glioma in the adult? RECOMMENDATION: LEVEL I: Histopathological analysis of a representative surgical sample of the lesion should be used to provide the diagnosis of low-grade diffuse glioma. LEVEL III: Both frozen section and cytopathologic/smear evaluation should be used to aid the intra-operative assessment of low-grade diffuse glioma diagnosis. A resection specimen is preferred over a biopsy specimen, to minimize the potential for sampling error issues. TARGET POPULATION: Patients with histologically-proven WHO grade II diffuse glioma. QUESTION: In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is testing for IDH1 mutation (R132H and/or others) warranted? If so, is there a preferred method? LEVEL II: IDH gene mutation assessment, via IDH1 R132H antibody and/or IDH1/2 mutation hotspot sequencing, is highly-specific for low-grade diffuse glioma, and is recommended as an additional test for classification and prognosis. TARGET POPULATION: Patients with histologically-proven WHO grade II diffuse glioma. QUESTION: In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is testing for 1p/19q loss warranted? If so, is there a preferred method? LEVEL III: 1p/19q loss-of-heterozygosity testing, by FISH, array-CGH or PCR, is recommended as an additional test in oligodendroglial cases for prognosis and potential treatment planning. TARGET POPULATION: Patients with histologically-proven WHO grade II diffuse glioma. QUESTION: In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is MGMT promoter methylation testing warranted? If so, is there a preferred method? RECOMMENDATION: There is insufficient evidence to recommend methyl-guanine methyl-transferase (MGMT) promoter methylation testing as a routine for low-grade diffuse gliomas. It is recommended that patients be enrolled in properly designed clinical trials to assess the value of this and related markers for this target population. TARGET POPULATION: Patients with histologically-proven WHO grade II diffuse glioma. QUESTION: In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is Ki-67/MIB1 immunohistochemistry warranted? If so, is there a preferred method to quantitate results? LEVEL III: Ki67/MIB1 immunohistochemistry is recommended as an option for prognostic assessment.

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

QUESTION: What is the optimal imaging technique to be used in the diagnosis of a suspected low grade glioma, specifically: which anatomic imaging sequences are critical for most accurately identifying or diagnosing a low grade glioma (LGG) and do non-anatomic imaging methods and/or sequences add to the diagnostic specificity of suspected low grade gliomas? TARGET POPULATION: These recommendations apply to adults with a newly diagnosed lesion with a suspected or histopathologically proven LGG. LEVEL II: In patients with a suspected brain tumor, the minimum magnetic resonance imaging (MRI) exam should be an anatomic exam with both T2 weighted and pre- and post-gadolinium contrast enhanced T1 weighted imaging. CRITICAL IMAGING FOR THE IDENTIFICATION AND DIAGNOSIS OF LOW GRADE GLIOMA: LEVEL II: In patients with a suspected brain tumor, anatomic imaging sequences should include T1 and T2 weighted and Fluid Attenuation Inversion Recovery (FLAIR) MR sequences and will include T1 weighted imaging after the administration of gadolinium based contrast. Computed tomography (CT) can provide additional information regarding calcification or hemorrhage, which may narrow the differential diagnosis. At a minimum, these anatomic sequences can help identify a lesion as well as its location, and potential for surgical intervention. IMPROVEMENT OF DIAGNOSTIC SPECIFICITY WITH THE ADDITION OF NON-ANATOMIC (PHYSIOLOGIC AND ADVANCED IMAGING) TO ANATOMIC IMAGING: LEVEL II: Class II evidence from multiple studies and a significant number of Class III series support the addition of diffusion and perfusion weighted MR imaging in the assessment of suspected LGGs, for the purposes of discriminating the potential for tumor subtypes and identification of suspicion of higher grade diagnoses. LEVEL III: Multiple series offer Class III evidence to support the potential for magnetic resonance spectroscopy (MRS) and nuclear medicine methods including positron emission tomography and single-photon emission computed tomography imaging to offer additional diagnostic specificity although these are less well defined and their roles in clinical practice are still being defined. QUESTION: Which imaging sequences or parameters best predict the biological behavior or prognosis for patients with LGG? TARGET POPULATION: These recommendations apply to adults with a newly diagnosed lesion with a suspected or histopathologically proven LGG. RECOMMENDATION: Anatomic and advanced imaging methods and prognostic stratification LEVEL III: Multiple series suggest a role for anatomic and advanced sequences to suggest prognostic stratification among low grade gliomas. Perfusion weighted imaging, particularly when obtained as a part of diagnostic evaluation (as recommended above) can play a role in consideration of prognosis. Other imaging sequences remain investigational in terms of their role in consideration of tumor prognosis as there is insufficient evidence to support more formal recommendations as to their use at this time. QUESTION: What is the optimal imaging technique to be used in the follow-up of a suspected (or biopsy proven) LGG? TARGET POPULATION: This recommendation applies to adults with a newly diagnosed low grade glioma. LEVEL II: In patients with a diagnosis of LGG, anatomic imaging sequences should include T2/FLAIR MR sequences and T1 weighted imaging before and after the administration of gadolinium based contrast. Serial imaging should be performed to identify new areas of contrast enhancement or significant change in tumor size, which may signify transformation to a higher grade. LEVEL III: Advanced imaging utility may depend on tumor subtype. Multicenter clinical trials with larger cohorts are needed. For astrocytic tumors, baseline and longitudinal elevations in tumor perfusion as assessed by dynamic susceptibility contrast perfusion MRI are associated with shorter time to tumor progression, but can be difficult to standardize in clinical practice. For oligodendrogliomas and mixed gliomas, MRS may be helpful for identification of progression.

Management of patients with recurrence of diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline.

TARGET POPULATION: These recommendations apply to adult patients with recurrent low-grade glioma (LGG) with initial pathologic diagnosis of a WHO grade II infiltrative glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma). QUESTION: Do pathologic and molecular characteristics predict outcome/malignant transformation at recurrence? RECOMMENDATIONS: IDH STATUS AND RECURRENCE: (Level III) IDH mutation status should be determined as LGGs with IDH mutations have a shortened time to recurrence. It is unclear whether knowledge of IDH mutation status provides benefit in predicting time to progression or overall survival. TP53 STATUS AND RECURRENCE: (Level III) TP53 mutations occur early in LGG pathogenesis, remain stable, and are not recommended as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. MGMT STATUS AND RECURRENCE: (Level III) Assessment of MGMT status is recommended as an adjunct to assessing prognosis as LGGs with MGMT promoter methylation are associated with shorter PFS (in the absence of TMZ) and longer post-recurrence survival (in the presence of TMZ), ultimately producing similar overall survival to LGGs without MGMT methylation. The available retrospective reports are conflicting and comparisons between reports are limited CDK2NA STATUS AND RECURRENCE: (Level III) Assessment of CDK2NA status is recommended when possible as the loss of expression of the CDK2NA via either methylation or loss of chromosome 9p is associated with malignant progression of LGGs. PROLIFERATIVE INDEX AND RECURRENCE: (Level III) It is recommended that proliferative indices (MIB-1 or BUdR) be measured in LGGs as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival. 1P/19Q STATUS AND RECURRENCE: There is insufficient evidence to make any recommendations. QUESTION: What role does chemotherapy have in LGG recurrence? RECOMMENDATIONS: TEMOZOLOMIDE AND RECURRENCE: (Level III) Temozolomide is recommended in the therapy of recurrent LGG as it may improve clinical symptoms. Oligodendrogliomas and tumors with 1p/19q co-deletion may derive the most benefit. PCV AND RECURRENCE: (Level III) PCV is recommended in the therapy of LGG at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. CARBOPLATIN AND RECURRENCE : (Level III) Carboplatin is not recommended as there is no significant benefit from carboplatin as single agent therapy for recurrent LGGs. OTHER TREATMENTS (NITROSUREAS, HYDROXYUREA/IMANITIB, IRINOTECAN, PACLITAXEL) AND RECURRENCE: There is insufficient evidence to make any recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess these chemotherapeutic agents. QUESTION: What role does radiation have in LGG recurrence? RECOMMENDATIONS: RADIATION AT RECURRENCE WITH NO PREVIOUS IRRADIATION: (Level III) Radiation is recommended at recurrence if there was no previous radiation treatment. RE-IRRADIATION AT RECURRENCE: (Level III) It is recommended that re-irradiation be considered in the setting of LGG recurrence as it may provide benefit in disease control. SURGERY AT RECURRENCE: There is insufficient evidence to make any specific recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess the role of surgery at recurrence.

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. 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. 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. 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 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.