Brainstem gliomas in adults: prognostic factors and classification

Prediction of H3K27M Alteration Status in Brainstem Glioma Using Multi-Shell Diffusion MRI Metrics

BACKGROUND

Multi-shell diffusion characteristics may help characterize brainstem gliomas (BSGs) and predict H3K27M status.

PURPOSE

To identify the diffusion characteristics of BSG patients and investigate the predictive values of various diffusion metrics for H3K27M status in BSG.

STUDY TYPE

Prospective.

POPULATION

Eighty-four BSG patients (median age 10.5 years [IQR 6.8-30.0 years]) were included, of whom 56 were pediatric and 28 were adult patients.

FIELD STRENGTH/SEQUENCE

3 T, multi-shell diffusion imaging.

ASSESSMENT

Diffusion kurtosis imaging and neurite orientation dispersion and density imaging analyses were performed. Age, gender, and diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, radial diffusivity (RD), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis, intracellular volume fraction (ICVF), orientation dispersion index, and isotropic volume fraction (ISOVF), were compared between H3K27M-altered and wildtype BSG patients.

STATISTICAL TESTS

Chi-square test, Mann-Whitney U test, multivariate analysis of variance (MANOVA), step-wise multivariable logistic regression. P-values <0.05 were considered significant.

RESULTS

82.4% pediatric and 57.1% adult patients carried H3K27M alteration. In the whole group, the H3K27M-altered BSGs demonstrated higher FA, AK and lower RD, ISOVF. The combination of age and median ISOVF showed fair performance for H3K27M prediction (AUC = 0.78). In the pediatric group, H3K27M-altered BSGs showed higher FA, AK, MK, ICVF and lower RD, MD, ISOVF. The combinations of median ISOVF, 5th percentile of FA, median MK and median MD showed excellent predictive power (AUC = 0.91). In the adult group, H3K27M-altered BSGs showed higher ICVF and lower RD, MD. The 75th percentile of RD demonstrated fair performance for H3K27M status prediction (AUC = 0.75).

DATA CONCLUSION

Different alteration patterns of diffusion measures were identified between H3K27M-altered and wildtype BSGs, which collectively had fair to excellent predictive value for H3K27M alteration status, especially in pediatric patients.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Brainstem Gliomas With Isocitrate Dehydrogenase Mutation: Natural History, Clinical-Radiological Features, Management Strategy, and Long-Term Outcome

BACKGROUND AND OBJECTIVES

This study aimed to investigate the clinical, radiological, pathological features, treatment options, and outcomes of isocitrate dehydrogenase (IDH)-mutant brainstem gliomas (BSG-IDHmut).

METHODS

A retrospective analysis of 22 patients diagnosed with BSG-IDHmut and treated at our institution from January 2011 to January 2017 was performed. Their clinical, radiological data, and long-term outcomes were collected and analyzed.

RESULTS

The median age of patients was 38.5 years, with a male predominance (63.6%). All patients had IDH1 and TP53 mutations, with noncanonical IDH mutations in 59.1% of cases, 06-methylguanine-DNA methyltransferase promoter methylation in 55.6%, and alpha-thalassemia mental retardation X-linked loss in 63.2%, respectively. Tumors were primarily located in the pontine-medullary oblongata (54.5%) and frequently involved the pontine brachium (50%). Most tumors exhibited ill-defined boundaries (68.2%), no T2-FLAIR mismatch (100%), and no contrast enhancement (86.3%). Two radiological growth patterns were also identified: focal and extensively infiltrative, which were associated with the treatment strategy when tumor recurred. Seven patients (31.8%) received surgery only and 15 (68.2%) surgery plus other therapy. The median overall survival was 124.8 months, with 1-year, 2-year, 5-year, and 10-year survival rates of 81.8%, 68.2%, 54.5%, and 13.6%, respectively. Six patients experienced tumor recurrence, and all retained their radiological growth patterns, with 2 transformed into central nervous system World Health Organization grade 4.

CONCLUSION

BSG-IDHmut represents a unique subgroup of brainstem gliomas with distinctive features and more favorable prognosis compared with other brainstem gliomas. Further research is required to better understand the molecular mechanisms and optimize treatment strategies for this rare and complex disease.

Decoding the puzzle: A multidisciplinary systematic review of adult brainstem glioma

Adult brainstem gliomas (BSGs) are a group of rare central nervous system tumors with varying prognoses and controversial standard treatment strategies. To provide an overview of current trends, a systematic review using the PRISMA guidelines, Class of evidence (CE) and strength of recommendation (SR), was conducted. The review identified 27 studies. Surgery was found to have a positive impact on survival, particularly for focal lesions with CE II SR C. Stereotactic image-guided biopsy was recommended when resective surgery was not feasible with CE II and SR B. The role of systemic treatments remains unclear. Eight studies provided molecular biology data. This review gathers crucial literature on diagnosis and management of adult BSGs. It provides evidence-based guidance with updated recommendations for diagnosing and treating, taking into account recent molecular and genetic advancements. The importance of brain biopsy is emphasized to optimize treatment using emerging genetic-molecular findings and explore potential targeted therapies.

NTMS based tractography and segmental diffusion analysis in patients with brainstem gliomas: Risk stratification and clinical potential

Introduction

Surgery on the brainstem level is associated with a high-risk of postoperative morbidity. Recently, we have introduced the combination of navigated transcranial magnetic stimulation (nTMS) and diffusion tensor imaging (DTI) tractography to define functionally relevant motor fibers tracts on the brainstem level to support operative planning and risk stratification in brainstem cavernomas.

Research question

Evaluate this method and assess it's clinical impact for the surgery of brainstem gliomas.

Material and methods

Patients with brainstem gliomas were examined preoperatively with motor nTMS and DTI tractography. A fractional anisotropy (FA) value of 75% of the individual FA threshold (FAT) was used to track descending corticospinal (CST) and -bulbar tracts (CBT). The distance between the tumor and the somatotopic tracts (hand, leg, face) was measured and diffusion parameters were correlated to the patients' outcome.

Results

12 patients were enrolled in this study, of which 6 underwent surgical resection, 5 received a stereotactic biopsy and 1 patient received conservative treatment. In all patients nTMS mapping and somatotopic tractography were performed successfully. Low FA values correlated with clinical symptoms revealing tract alteration by the tumor (p = 0.049). A tumor-tract distance (TTD) above 2 mm was the critical limit to achieve a safe complete tumor resection.

Discussion and conclusion

nTMS based DTI tractography combined with local diffusion analysis is a valuable tool for preoperative visualization and functional assessment of relevant motor fiber tracts, improving planning of safe entry corridors and perioperative risk stratification in brainstem gliomas tumors. This technique allows for customized treatment strategy to maximize patients' safety.

[Primary tumors of the brain stem. State of the problem]

Primary brainstem gliomas are still poorly studied in neurooncology. This concept includes tumors with different histological and genetic features, as well as variable clinical course and outcomes. Nevertheless, treatment implies radiotherapy without a clear idea of morphological substrate of disease in 80% of cases. Small number of studies and insufficient data on histological and genetic nature of brainstem tumors complicate clear diagnostic and treatment algorithms. This review provides current information regarding primary glial brainstem tumors. Appropriate problems and objectives are highlighted. The purpose of the review is to provide a comprehensive and updated understanding of the current state of brainstem glial tumors and to identify areas requiring further study for improvement of diagnosis and treatment of these diseases. Brainstem tumors are an understudied problem with small amount of data that complicates optimal treatment strategies. Further researches and histological verification are required to develop new methods of therapy, especially for diffuse forms of neoplasms.

Surgical Management of Adult Brainstem Gliomas: A Systematic Review and Meta-Analysis

The present review aims to investigate the survival and functional outcomes in adult high-grade brainstem gliomas (BGSs) by comparing data from resective surgery and biopsy. MEDLINE, EMBASE and Cochrane Library were screened to conduct a systematic review of the literature, according to the PRISMA statement. Analysis was limited to articles including patients older than 18 years of age and those published from 1990 to September 2022. Case reports, review articles, meta-analyses, abstracts, reports of aggregated data, and reports on multimodal therapy where surgery was not the primary treatment were excluded. The ROBINS-I tool was applied to evaluate the risk of bias. Six studies were ultimately considered for the meta-analysis. The resective group was composed of 213 subjects and the bioptic group comprised 125. The analysis demonstrated a survival benefit in those patients in which an extensive resection was possible (STR HR 0.59 (95% CI 0.42, 0.82)) (GTR HR 0.63 (95% CI 0.43, 0.92)). Although surgical resection is associated with increased survival, the significantly higher complication rate makes it difficult to recommend surgery instead of biopsy for BSGs. Future investigations combining volumetric data and molecular profiles could add important data to better define the proper indication between resection and biopsy.

The Role of Advanced MRI Sequences in the Diagnosis and Follow-Up of Adult Brainstem Gliomas: A Neuroradiological Review

The 2021 WHO (World Health Organization) classification of brain tumors incorporated the rapid advances in the molecular, genetic, and pathogenesis understanding of brain tumor pathogenesis, behavior, and treatment response. It revolutionized brain tumor classification by placing great emphasis on molecular types and completely splitting adult-type and pediatric-type diffuse gliomas. Brainstem gliomas (BSGs) are the leading primary tumors of the brainstem, although they are quite uncommon in adults compared with the pediatric population, representing less than 2% of adult gliomas. Surgery is not always the treatment of choice since resection is rarely feasible and does not improve overall survival, and biopsies are not generally performed since the location is treacherous. Therefore, MRI (Magnetic Resonance Imaging) without and with gadolinium administration represents the optimal noninvasive radiological technique to suggest brainstem gliomas diagnosis, plan a multidisciplinary treatment and for follow-up evaluations. The MRI protocol encompasses morphological sequences as well as functional and advanced sequences, such as DWI/ADC (Diffusion-Weighted Imaging/Apparent Diffusion Coefficient), DTI (Diffusion Tensor Imaging), PWI (Perfusion-Weighted Imaging), and MRS (Magnetic Resonance Spectroscopy), which improve the accuracy of the diagnosis of BSGs by adding substantial information regarding the cellularity, the infiltrative behavior toward the v fiber tracts, the vascularity, and the molecular changes. Brainstem gliomas have been divided into four categories on the basis of their MRI radiological appearance, including diffuse intrinsic low-grade gliomas, enhancing malignant gliomas, localized tectal gliomas, and other forms. The aim of our review is to provide insight into the role of advanced MRI sequences in the diagnosis and follow-up of adult brainstem gliomas.

Medullary brainstem gliomas in an adult: A rare case report and challenging tumor

Background

Medullary brainstem lesions are rare tumors that are challenging to treat due to their location in the brainstem, which controls vital functions such as breathing, heart rate, and blood pressure. While the most common subtype is the aggressive diffuse intrinsic pontine glioma, other subtypes exist, including focal brainstem gliomas and cervicomedullary gliomas. The prognosis for patients with brainstem gliomas is generally poor, and treatment options are limited. Early detection and treatment are crucial to improve outcomes for patients with these tumors.

Case Description

In this case report, the authors describe a 28-year-old male from Saudi Arabia who presented with headaches and vomiting. Imaging studies and clinical examination revealed a high-grade astrocytoma medullary brainstem lesion. The patient underwent radiation therapy and chemotherapy, effectively controlling tumor growth and improving his quality of life. However, a residual tumor remained, and the patient underwent neurosurgery to resect the remaining tumor was successful in removing the tumor, and the patient showed significant improvement in his symptoms and overall health.

Conclusion

This case highlights the importance of early detection and treatment of medullary brainstem lesions. While radiation therapy and chemotherapy are primary treatment options, neurosurgery may be necessary to resect residual tumors. In addition, cultural and social factors may need to be considered in managing these tumors in Saudi Arabia.

Exploration of the prognostic value of the resection of adult brainstem high-grade glioma based on competing risk model, propensity score matching, and conditional survival rate

BACKGROUND

Adult brainstem high-grade glioma (HGG) is a refractory disease, and the treatment strategy of resection is still controversial.

OBJECTIVE

To investigate the prognostic value of brainstem HGG resection in adults.

METHODS

We collected 126,386 samples from the Surveillance, Epidemiology, and End Results (SEER) database between 1998 and 2016, and screened 973 patients diagnosed with adult brainstem HGG, who were in turn, grouped into 899 cases of non-resections and 74 cases of resections. Competing risk models were used to screen independent prognostic factors. Propensity score matching (PSM) was performed to reduce the influence of confounding factors. Conditional survival (CS) rate was considered to evaluate the changes in overall survival (OS) and disease-specific survival (DSS) of patients with HGG over time.

RESULTS

Based on the competing risk model and PSM, univariate analysis showed that age ≥ 45 years and male gender were poor prognostic factors for adult brainstem HGG. No previous history of glioma was a beneficial factor. Multivariate analysis revealed only the absence of a history of glioma to be a favorable prognostic factor. Considering the CS rate of the resection group, after the patient had survived for 3 years, the OS and DSS remained unchanged at 100% during the fourth and fifth years, whereas in the non-resection group, the OS and DSS of the patients were 82% and 74%, respectively.

CONCLUSION

Adult brainstem HGG resection has a poor prognosis in the early stage; however, patients have a potentially significant survival benefit after 3 years of survival.

Role of neuronavigation in the surgical management of brainstem gliomas

Objective

NeuroNavigation (NN) is a widely used intraoperative imaging guidance technique in neurosurgical operations; however, its value in brainstem glioma (BSG) surgery is inadequately reported and lacks objective proof. This study aims to investigate the applicational value of NN in BSG surgery.

Method

A retrospective analysis was performed on 155 patients with brainstem gliomas who received craniotomy from May 2019 to January 2022 at Beijing Tiantan Hospital. Eighty-four (54.2%) patients received surgery with NN. Preoperative and postoperative cranial nerve dysfunctions, muscle strength, and Karnofsky (KPS) were evaluated. Patients' radiological features, tumor volume, and extent of resection (EOR) were obtained from conventional MRI data. Patients' follow-up data were also collected. Comparative analyses on these variables were made between the NN group and the non-NN group.

Result

The usage of NN is independently related to a higher EOR in diffuse intrinsic pontine glioma (DIPG) (p=0.005) and non-DIPG group (p<0.001). It was observed that fewer patients in the NN group suffered from deterioration of KPS (p=0.032) and cranial nerve function (p=0.017) in non-DIPG group, and deterioration of muscle strength (p=0.040) and cranial nerve function (p=0.038) in DIPG group. Moreover, the usage of NN is an independent protective factor for the deterioration of KPS (p=0.04) and cranial nerve function (p=0.026) in non-DIPG patients and the deterioration of muscle strength (p=0.009) in DIPG patients. Furthermore, higher EOR subgroups were found to be independently related to better prognoses in DIPG patients (p=0.008).

Conclusion

NN has significant value in BSG surgery. With the assistance of NN, BSG surgery achieved higher EOR without deteriorating patients' functions. In addition, DIPG patients may benefit from the appropriate increase of EOR.

A Case Series of Stereotactic Biopsy of Brainstem Lesions through the Transfrontal Approach

Background and Importance Brainstem lesions may be unresectable or unapproachable. Regardless, the histopathological diagnosis is fundamental to determine the most appropriate treatment. We present our experience with transfrontal stereotactic biopsy technique for brainstem lesions as a safe and effective surgical route even when contralateral transhemispheric approach is required for preservation of eloquent tissue.

Clinical Presentation Twenty-five patients underwent surgery by transfrontal approach. Medical records were reviewed for establishing the number of patients who had postoperative histopathological diagnosis and postoperative complications. Twenty-four patients (18 adults and 7 children) had histopathological diagnosis. There were 18 astrocytomas documented, of which 12 were high grade and 6 low grade. The other diagnoses included viral encephalitis, post–renal transplant lymphoproliferative disorder, nonspecific chronic inflammation, Langerhans cell histiocytosis, and two metastases. No case was hindered by cerebrospinal fluid loss or ventricular entry. Complications included a case of mesencephalic hemorrhage with upper limb monoparesis and a case of a partially compromised third cranial nerve in another patient without associated bleeding.

Conclusion Stereotactic biopsy of brainstem lesions by transfrontal ipsilateral or transfrontal transhemispheric contralateral approaches is a safe and effective surgical approach in achieving a histopathological diagnosis in both pediatric and adult populations.

Roles and outcomes of stereotactic biopsy for adult patients with brainstem lesion

PURPOSE

This study aimed to assess the benefit-risk ratio by determining diagnostic yield and safety of brainstem biopsies in adult patients. The secondary objectives were (i) to compare brainstem biopsy safety and postbiopsy patients' outcomes and survival with those of patients biopsied for a brain or cerebellar lesion, and (ii) to assess the impact of brainstem biopsy on final diagnosis and further therapeutic management.

METHODS

Among 1784 stereotactic biopsies performed in adult patients at a tertiary center between April 2009 and October 2020, we retrospectively examined 50 consecutive brainstem biopsies. We compared variables regarding diagnostic yield, safety and post-biopsy outcomes between brainstem biopsy patients and brain/cerebellum biopsy patients.

RESULTS

Brainstem biopsy led to a diagnosis in 86% of patients (94.6% in patients with suspected tumor). Lesion contrast enhancement on imaging was the sole predictor of obtaining a diagnosis. Rates of symptomatic complications and mortality were significantly higher in brainstem biopsy patients compared to brain/cerebellum biopsy patients (20% vs 0%; p < 0.001 and 6% vs 0%; p = 0.01, respectively). Transfrontal trajectory and prebiopsy swallowing disorders were predictors of brainstem biopsy-related symptomatic complications. Brainstem biopsy findings led to diagnostic change in 22% of patients.

CONCLUSIONS

Stereotactic biopsy in adult patients with brainstem lesion has a high diagnostic yield. Although stereotactic brainstem biopsy is associated with more functional and fatal complications than biopsies targeting the brain/cerebellum, its safety profile appears acceptable. Thus, the benefit-risk ratio of stereotactic biopsy in patients with brainstem lesion is favorable but should nevertheless be carefully weighted on a case-by-case basis.

The potential of B7-H6 as a therapeutic target in cancer immunotherapy

Immune checkpoints are vital molecules that regulate T-cell function by activation or inhibition. Among the immune checkpoint molecules, the B7-family proteins are significantly involved in the immune escape of tumor cells. By binding to inhibitory receptors, they can suppress T-cell-mediated immunity. B7-family proteins are found at various stages of tumor microenvironment formation and promote tumorigenesis and tumor progression. B7-H6 (encoded by gene NCR3LG1) is a prominent member of the family. It has unique immunogenic properties and is involved in natural killer (NK) cell immunosurveillance by binding to the NKp30 receptor. High B7-H6 expression in certain tumor types and shortage of or low expression in healthy cells - except in cases of inflammatory or microbial stimulation - have made the protein an attractive target of research activities in recent years. The avoidance of NK-mediated B7-H6 detection is a mechanism through which tumor cells escape immune surveillance. The stimulation of tumorigenesis occurs by suppressing caspase cascade initiation and anti-apoptosis activity stimulation via the STAT3 pathway. The B7-H6-NKp30 complex on the tumor membrane activates the NK cells and releases both tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). B7-H6 is highly expressed in a wide range of tumor cells, including glioma, hematologic malignant tumors, and breast cancer cells. Clinical examination of cancer patients indicated that the expression of B7-H6 is related to distant metastasis status and permits postoperative prognosis. Because of its unique properties, B7-H6 has a high potential be utilized as a biological marker for cancer diagnosis and prognosis, as well as a target for novel treatment options.

Compassionate Treatment of Brainstem Tumors with Boron Neutron Capture Therapy: A Case Series

Brainstem tumors are heterogenous and cancerous glioma tumors arising from the midbrain, pons, and the medulla that are relatively common in children, accounting for 10% to 20% of all pediatric brain tumors. However, the prognosis of aggressive brainstem gliomas remains extremely poor despite aggressive treatment with chemotherapy and radiotherapy. That means there are many life-threatening patients who have exhausted all available treatment options and are beginning to face end-of-life stage. Therefore, the unique properties of highly selective heavy particle irradiation with boron neutron capture therapy (BNCT) may be well suited to prolong the lives of patients with end-stage brainstem gliomas. Herein, we report a case series of life-threatening patients with end-stage brainstem glioma who eligible for Emergency and Compassionate Use, in whom we performed a scheduled two fractions of salvage BNCT strategy with low treatment dosage each time. No patients experienced acute or late adverse events related to BNCT. There were 3 patients who relapsed after two fractionated BNCT treatment, characterized by younger age, lower T/N ratio, and receiving lower treatment dose. Therefore, two fractionated low-dose BNCT may be a promising treatment for end-stage brainstem tumors. For younger patients with low T/N ratios, more fractionated low-dose BNCT should be considered.

Adult diffuse intrinsic pontine glioma: clinical, radiological, pathological, molecular features, and treatments of 96 patients

OBJECTIVE

Unlike its pediatric counterpart, adult diffuse intrinsic pontine glioma (DIPG) remains largely unelucidated. In this study, the authors examined the clinical, radiological, pathological, molecular, and clinical aspects of 96 adult DIPGs.

METHODS

The National Brain Tumor Registry of China (April 2013-December 2019) was used to collect data on radiologically diagnosed adult DIPG patients. Survival analysis was conducted using Kaplan-Meier curves and univariate and multivariate Cox regression. The chi-square test/Wilcoxon rank-sum test and multivariable logistic regression were used to examine the clinical and radiological characteristics of patients with long-term survival (LTS). Interaction analyses between clinical factors were also conducted.

RESULTS

The median age at symptom onset was 33.5 years, and the median duration of symptoms was 4.5 months. The frequencies of H3K27M and IDH1 mutations were 37.2% and 26.5%, respectively. All adult DIPG patients had a median overall survival (OS) of 19.5 months, with 1-, 2-, and 3-year survival rates of 67.0%, 42.8%, and 36.0%, respectively. The median OS of 40 patients who did not undergo treatment was 13.4 months. Patients with H3K27M-mutant tumors had a poorer prognosis than those with IDH-mutant tumors (p < 0.001) and H3K27M(-)/IDH-wild-type tumors (p = 0.002), with a median OS of 11.4 months. The median OSs of patients with H3K27M-mutant tumors who received treatment and those who did not were 13.8 months and 7.5 months, respectively (p = 0.016). Among patients with and without a pathological diagnosis, H3K27M mutation (p < 0.001) and contrast enhancement on MRI (p = 0.003), respectively, imparted a worse prognosis. Treatments were the predictive factor for patients with H3K27M-mutant tumors (p = 0.038), whereas contrast enhancement on MRI was the prognostic factor for the H3K27M(-) group (p = 0.038). In addition, H3K27M mutation and treatment were significant predictors for patients with symptom duration ≤ 4 months (H3K27M, p = 0.020; treatment, p = 0.014) and tumors with no contrast enhancement (H3K27M, p = 0.003; treatment, p = 0.042). Patients with LTS were less likely to have cranial nerve palsy (p = 0.002) and contrast enhancement on MRI at diagnosis (p = 0.022).

CONCLUSIONS

It is recommended that all adult DIPG patients undergo genomic testing for H3K27M and IDH mutations. Despite the low prevalence, additional study is needed to better characterize the efficacy of various treatment modalities in adults with DIPG.

Brainstem Venous Congestion Due to Transverse-sigmoid Sinus Dural Arteriovenous Fistula: Case Report and Literature Review

Brainstem venous congestion due to dural arteriovenous fistula (dAVF) can mimic brainstem glioma and infarction. We report a case of a 56-year-old woman with a transverse-sigmoid sinus (TS) dAVF. On MRI, she presented with brainstem edema that was difficult to distinguish from brainstem glioma and infarction. She was referred to our hospital for mild dysarthria with right hemiparesis and a suspected left pontine glioma. On MRI, contrast enhancement of the lesion was demarcated by the pontine raphe, and the ipsilateral vein of Rosenthal was dilated. Cerebral angiography revealed TS dAVF with an isolated sinus. Transarterial followed by transvenous coil embolization was performed to reduce shunt flow, resulting in symptom improvement and normal findings on MRI and cerebral angiography. Brainstem venous congestion due to TS dAVF is as rare as adult brainstem glioma. Differentiating the above-mentioned three diseases on the basis of diagnostic imaging findings and clinical course is necessary for appropriate and timely treatment.

Malignant Progression of an IDH Mutant Brainstem Glioma in Adult

Brain stem gliomas (BSG) in adults are rare and less aggressive than those in children. However, the molecular profile of adult BSG cases has not been well characterized. We report a case of adult BSG with isocitrate dehydrogenase (IDH) mutation. A 43-year-old male was admitted to our hospital with diplopia and right-sided hypesthesia. An open biopsy led to the tumor being diagnosed as a diffuse astrocytoma. Immunohistochemically, the tumor was positive for IDH1 R132H, but negative for H3K27M. The patient received 54 Gy of local radiotherapy and adjuvant temozolomide, which resulted in the size of the lesion decreasing significantly. At 56 months after the initial diagnosis, the patient was referred to our hospital with a severe headache and ataxia. Magnetic resonance imaging (MRI) revealed a contrast-enhanced lesion in the brain stem, which extended into the left cerebellar hemisphere and brainstem. Partial tumor removal was performed, and a pathological examination revealed the features of glioblastoma. Immunohistochemically, the tumor was positive for IDH1 R132H and p53 and negative for ATRX. To the best of our knowledge, there are few reports about adult case of brain stem astrocytoma to be confirmed via histological and molecular examinations of the primary and recurrent tumor. We exhibit detailed pathological and molecular findings which resembles to IDH mutant supratentorial diffuse astrocytic tumors.

Prognosis of Patients With Brainstem Glioblastoma Based on "age, surgery and radiotherapy": A SEER Database Analysis

Introduction: Primary brainstem glioma is a rare tumor with a dismal prognosis that poses significant treatment challenges. The purpose of the current study is to identify and determine prognostic factors associated with survival in high-grade brainstem glioma patients. Methods: We gathered the data from the SEER database for the duration of years from 1973 to 2016 to examine the survival of patients particularly reported with the high-grade brainstem glioma and subsequently ascertained the potential impact of demographic features, tumor, and clinical characteristics on the overall survival of these patients. The survival patterns were assessed using Kaplan-Meier curves and Cox proportional hazards models. Propensity score matching (PSM) analysis was performed between patients with or without radiation therapy based on age and surgical resection to investigate the effect of radiotherapy on overall survival (OS). Results: A total 232 patient's data were obtained from the SEER database and included in this study. The median overall survival was 8 months. Kaplan-Meier survival analysis delineated that the patients who were in younger age (P = .001) and underwent surgery (P = .001) exhibited typically a better prognosis. Among 232 patients, a total of 204 patients were categorized as radiotherapy group (RG) received radiation therapy whereas 28 patients were considered as nonradiotherapy group (NRG), who were not receiving radiotherapy. Radiotherapy was associated with an improvement in the overall survival without statistical significance (P = .104). PSM was performed between RG and NRG based on age and surgical resection. After the PSM, 56 patients were included. Overall Survival was significantly different between both groups (P = .038). Conclusion: Furthermore, the patients with high-grade brain glioma who received "both radiotherapy and chemotherapy" exhibited significantly longer survival compared to the patients who received chemotherapy alone. Multivariate analysis showed that treatment with surgery and radiotherapy were considered as the independent prognostic factors (P < .05).

Experimental murine models of brainstem gliomas

As an intractable central nervous system (CNS) tumor, brainstem gliomas (BGs) are one of the leading causes of pediatric death by brain tumors. Owing to the risk of surgical resection and the little improvement in survival time after radiotherapy and chemotherapy, there is an urgent need to find reliable model systems to better understand the regional pathogenesis of the brainstem and improve treatment strategies. In this review, we outline the evolution of BG murine models, and discuss both their advantages and limitations in drug discovery.

Pilocytic Astrocytoma-Derived Cells in Peripheral Blood: A Case Report

Imaging limitations, invasive tissue biopsies and poor information over the course of treatment to evaluate ‘real-time’ tumor dynamics justify the emerging use of liquid biopsies in the field of brain tumors. Circulating tumor cells (CTCs) from high-grade astrocytomas might reach the circulation by crossing the blood–brain barrier. Here, for the first time, CTCs cytology in a case of pylocitic astrocytoma is described. An obstructive hydrocephalous due to a lateral mesencephalic tectum mass occluding the Silvio Aqueduct was diagnosed in a young, 18 years old, male. Considering the location of the tumor and the rapid deterioration of the neurological status, it has been decided to urgency treat the patient with ventriculoperitoneal shunting. Magnetic resonance imaging showed a nodular shaped lesion localized within the left lateral mesencephalic tectum. Stereotactic biopsy was not approachable due significant risk of neurological consequences. The diagnosis was performed by blood sampling, a non-invasive procedure for the patient, in order to provide tumor information. Cytopathological features on detected circulating atypical GFAP positive cells led to pilocytic diagnosis confirmed by the patient’s 68 months outcome.

Prognostic factors in adult brainstem glioma: a tertiary care center analysis and review of the literature

Introduction

Adult brainstem gliomas (BSGs) are rare central nervous system tumours characterized by a highly heterogeneous clinical course. Median survival times range from 11 to 84 months. Beyond surgery, no treatment standard has been established. We investigated clinical and radiological data to assess prognostic features providing support for treatment decisions.

Methods

34 BSG patients treated between 2000 and 2019 and aged ≥ 18 years at the time of diagnosis were retrospectively identified from the databases of the two largest Austrian Neuro-Oncology centres. Clinical data including baseline characteristics, clinical disease course, applied therapies, the outcome as well as neuroradiological and neuropathological findings were gathered and analysed. The tumour apparent diffusion coefficient (ADC), volumetry of contrast-enhancing and non-contrast-enhancing lesions were determined on magnetic resonance imaging scans performed at diagnosis.

Results

The median age at diagnosis was 38.5 years (range 18–71 years). Tumour progression occurred in 26/34 (76.5%) patients after a median follow up time of 19 months (range 0.9–236.2). Median overall survival (OS) and progression-free survival (PFS) was 24.1 months (range 0.9–236.2; 95% CI 18.1–30.1) and 14.5 months (range 0.7–178.5; 95% CI 5.1–23.9), respectively. Low-performance status, high body mass index (BMI) at diagnosis and WHO grading were associated with shorter PFS and OS at univariate analysis (p < 0.05, log rank test, respectively). ADC values below the median were significantly associated with shorter OS (14.9 vs 44.2 months, p = 0.018).

Conclusion

ECOG, BMI, WHO grade and ADC values were associated with the survival prognosis of BSG patients and should be included in the prognostic assessment.

Adult brainstem glioma presenting with isolated persistent hemifacial spasm or facial nerve palsy

OBJECT

Adult brainstem gliomas are a rare group of heterogeneous brain tumors. Classical clinical presentation includes progressive impairment of cranial nerves associated with long tract signs. The prognosis and response to treatment are poor; nevertheless, some patients do have a long survival. The objective of this study was to describe a series of patients with an isolated persistent hemifacial spasm and/or facial nerve palsy as the presenting symptom of a brainstem glioma.

METHODS

Fourteen patients from 3 French hospitals (Paris, Caen, Lille) were included. Clinical and radiological features and overall survival were retrospectively analyzed. A review of the literature of similar cases was performed.

RESULTS

Mean age at diagnosis was 35 years (range 19-57 years). Mean duration of facial nerve involvement before diagnosis was 17 months (range 1-48 months). Tumors were characterized on MRI by a lateralized location in the pons, a T1-weighted hyposignal, a T2-weighted hypersignal and no contrast enhancement after Gadolinium injection except for 2 cases. Biopsies were performed in 10 cases and showed 8 low-grade and 2 high-grade gliomas. All the patients were initially treated with radiotherapy and 6 patients with chemotherapy after progression. Eleven patients died from tumor progression. Median survival time was 90 months.

CONCLUSIONS

Adult brainstem gliomas revealed by a progressive isolated involvement of the facial nerve seem to have particular clinico-radiological features of slow progressive tumors and may be associated with long patient survival.

Stereotactic biopsies of brainstem lesions: which approach?

BACKGROUND

Stereotactic biopsies for brainstem lesions are frequently performed to yield an accurate diagnosis and help guide subsequent management. In this study, we summarize our experience with different stereotactic approaches to brainstem lesions of different locations and discuss possible implications for safety and diagnostic yield.

METHODS

We retrospectively analyzed 23 adult patients who underwent a stereotactic biopsy for brainstem lesions between October 2011 and December 2019. Depending on the location supra- or infratentorial, trajectories were planned. We assessed the postoperative complications during the hospital stay as well as the diagnostic yield.

RESULTS

A supratentorial transfrontal approach was used in 16 (70%) cases, predominantly for lesions in the midbrain, upper pons, and medulla oblongata. An infratentorial, transcerebellar-transpeduncular approach was used in 7 (30%) cases mainly for lesions within the lower pons. All biopsies were confirmed to represent pathological tissue and a definitive diagnosis was achieved in 21 cases (91%). Three patients (13%) had transient weakness in the contralateral part of the body in the immediate postoperative period, which improved spontaneously. There was no permanent morbidity or mortality in this series of patients.

CONCLUSION

Lesions of various locations within the brainstem can be successfully targeted via either a supratentorial transfrontal or an infratentorial transcerebellar transpeduncular approach. Our high diagnostic yield of over 90% and the low rate of complications underlines the diagnostic importance of this procedure in order to guide the medical management of these patients.

Surgical considerations for maximal safe resection of exophytic brainstem glioma in the pediatric age group

Background:

Brainstem glioma is the leading cause of morbidity and mortality among all central nervous system tumors, especially in childhood as it represents about 20% of all pediatric brain tumors. Therefore, this study aimed to present our experience in a tertiary center in a developing country with limited resources for the surgical management of exophytic brainstem gliomas.

Methods:

This retrospective study included pediatric patients with brainstem (midbrain, pontine, or medullary) focal or diffuse gliomas whether low or high grade that had dorsal, ventral, or lateral exophytic component who were presented to our hospitals from January 2019 to January 2021. The patients’ data were collected, such as age, sex, preoperative and postoperative clinical condition, radiological data, surgical approach, extent of tumor removal, histopathology, follow-up period, and adjuvant therapy.

Results:

A total of 23 patients were included in this study. The telovelar approach was used in 17 patients, the supracerebellar infratentorial approach in three patients, and the retrosigmoid, transcerebellar, and occipital transtentorial approach once for each patient. Twenty patients underwent near-total excision, and three underwent subtotal excision. Two-thirds of our cases (17 patients) were low-grade gliomas, with the remaining one-third comprising entirely of either anaplastic astrocytoma (five patients) or glioblastoma multiforme (one patient). The follow-up period of the patients extended from 3 months to 24 months.

Conclusion:

Exophytic brainstem glioma surgery can result in good outcomes with minimal complications when near-total excision is attempted through a properly chosen approach and adherence to some surgical techniques and considerations.

Retrospective study of diffuse intrinsic pontine glioma in the Belgian population: a 25 year experience

INTRODUCTION

Diffuse intrinsic pontine glioma is a rare disease with a high mortality. Our primary aim was to determine the incidence of this disease in Belgium. Secondly, we wanted to compare the treatment approach of Belgian pediatric oncology centres, to investigate possibilities for improvement.

METHODS

We retrospectively collected and analysed data on DIPG-patients diagnosed between 1994 and 2018 and recorded in the Belgian Cancer Registry. We included patients ≤ 18 years who were followed in one of the eight Belgian pediatric oncology centres.

RESULTS

We included 100 patients. Files were complete in 87 patients. We observed an increase in diagnoses with an incidence of 3.1 per 1,000,000 persons (aged 0-≤ 18) per year over the last 5 years compared to an overall incidence of 1.8. Biopsy was performed at diagnosis in 51.7% of patients. In one fifth this was study-related. Mutation analysis was known in eight patients, of which six showed the H3 K27M-mutation. 58.8% of patients received chemotherapy, without a significant survival benefit. 12.6% of patients were included in a clinical trial. Biopsy rate and the use of chemotherapy differed widely between centres. Mean OS and PFS were 10.49 and 4.87 months respectively. We observed an improved survival over time.

CONCLUSIONS

Over the past 25 years, we observed an increase of new DIPG-diagnoses. Outcome in our cohort is comparable with literature findings. We demonstrate an important heterogeneity in treatment approach between different centres and limited inclusion in clinical trials. Therefore, collaboration between centres and inclusion of patients in clinical trials is much needed.

Clinical and Genetic Features of Brainstem Glioma in Adults: A Report of 50 Cases in a Single Center

Background and Purpose

Brainstem gliomas (BSGs) in adults are rare brain tumors with dismal outcomes. The aim of this study was to determine the clinical and genetic features in a series of BSGs and their association with the prognosis.

Methods

Fifty patients who underwent a stereotactic biopsy between January 2016 and April 2018 at a single institution were collected. Data on clinicopathological characteristics were analyzed and factors associated with patient survival were identified using a Cox regression model.

Results

The median age at diagnosis was 55.5 years, and 62% of the patients were male. Glioblastoma (44%) accounted for the largest proportion of BSGs, and oligodendroglioma (2 of 50) was rarely encountered. The IDH mutation (6 of 44) occurred infrequently in astrocytomas, and IDH-mutant tumors harbored both ATRX loss and MGMT promoter methylation at a relatively low level. Wild-type IDH astrocytomas were identified as having high rates of 1p/19q codeletion (5 of 38) and loss of heterozygosity 1p (8 of 38) or 19q (8 of 38) only. In diffuse midline glioma H3K27M mutant, MGMT promoter methylation occurred in three of four cases. Patients were offered radiotherapy and/or concurrent/adjuvant temozolomide chemotherapy, and their median survival time was 13 months. Multivariate analysis revealed that a low tumor grade, absence of tumor enhancement, duration of symptoms ≥3 months, Karnofsky performance status ≥70, and ATRX loss conferred a survival advantage.

Conclusions

Adult BSGs showed different molecular genetic characteristics, but also resembled supratentorial gliomas in their clinical features associated with oncological outcomes.

The role of diffusion tensor imaging and tractography in the surgical management of brainstem gliomas

OBJECTIVE

Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) have the ability to noninvasively visualize changes in white matter tracts, as well as their relationships with lesions and other structures. DTI/DTT has been increasingly used to improve the safety and results of surgical treatment for lesions in eloquent areas, such as brainstem cavernous malformations. This study aimed to investigate the application value of DTI/DTT in brainstem glioma surgery and to validate the spatial accuracy of reconstructed corticospinal tracts (CSTs).

METHODS

A retrospective analysis was performed on 54 patients with brainstem gliomas who had undergone surgery from January 2016 to December 2018 at Beijing Tiantan Hospital. All patients underwent preoperative DTI and tumor resection with the assistance of DTT-merged neuronavigation and electrophysiological monitoring. Preoperative conventional MRI and DTI data were collected, and the muscle strength and modified Rankin Scale (mRS) score before and after surgery were measured. The surgical plan was created with the assistance of DTI/DTT findings. The accuracy of DTI/DTT was validated by performing direct subcortical stimulation (DsCS) intraoperatively. Multiple linear regression was used to investigate the relationship between quantitative parameters of DTI/DTT (such as the CST score and tumor-to-CST distance [TCD]) and postoperative muscle strength and mRS scores.

RESULTS

Among the 54 patients, 6 had normal bilateral CSTs, 12 patients had unilateral CST impairments, and 36 had bilateral CSTs involved. The most common changes in the CSTs were deformation (n = 29), followed by deviation (n = 28) and interruption (n = 27). The surgical approach was changed in 18 cases (33.3%) after accounting for the DTI/DTT results. Among 55 CSTs on which DsCS was performed, 46 (83.6%) were validated as spatially accurate by DsCS. The CST score and TCD were significantly correlated with postoperative muscle strength (r = -0.395, p < 0.001, and r = 0.275, p = 0.004, respectively) and postoperative mRS score (r = 0.430, p = 0.001, and r = -0.329, p = 0.015, respectively). The CST score was independently linearly associated with postoperative muscle strength (t = -2.461, p = 0.016) and the postoperative mRS score (t = 2.052, p = 0.046).

CONCLUSIONS

DTI/DTT is a valuable tool in the surgical management of brainstem gliomas. With good accuracy, it can help optimize surgical planning, guide tumor resection, and predict the postoperative muscle strength and postoperative quality of life of patients.

Down-Regulation of PDCD4 Promotes Proliferation, Angiogenesis and Tumorigenesis in Glioma Cells

The programmed cell death 4 (PDCD4) tumor-suppressor gene regulates cell apoptosis, protein translation, signal transduction, and induction of mediators of inflammation. However, the mechanism by which PDCD4 is down-regulated and regulates tumor growth remains elusive. In this study, we showed that PDCD4 is down-regulated in glioma cells and acts as a tumor suppressor. Based on the TCGA data, we confirmed that AKT2, but not AKT1 or AKT3, interacts with PDCD4, thus leading to the suppression of PDCD4 in glioma cells. Moreover, the analysis suggested that PDCD4 regulates the expression of IL-5, CCL-5, VEGF, and CXCL10 via the NF-kB pathway. Additionally, depletion of levels of PDCD4 promoted angiogenic activity of glioma cells via the VEGF-STAT3 pathway. When tumor cells over-expressing PDCD4 were injected into nude mice, the increased expression of PDCD4 blocked tumorigenesis and prolonged overall survival. Our study indicates the need to develop drugs that can modulate the expression of PDCD4 and test their efficacy in clinical trials.

Pilocytic Astrocytoma: A Review of General, Clinical, and Molecular Characteristics

Pilocytic astrocytomas are the primary tumors most frequently found in children and adolescents, accounting for approximately 15.6% of all brain tumors and 5.4% of all gliomas. They are mostly found in infratentorial structures such as the cerebellum and in midline cerebral structures such as the optic nerve, hypothalamus, and brain stem. The present study aimed to list the main characteristics about this tumor, to better understand the diagnosis and treatment of these patients, and was conducted on search of the published studies available in NCBI, PubMed, MEDLINE, Scielo, and Google Scholar. It was possible to define the main histologic findings observed in these cases, such as mitoses, necrosis, and Rosenthal fibers. We described the locations usually most affected by tumor development, and this was associated with the most frequent clinical features. The comparison between the molecular diagnostic methods showed great use of fluorescent in situ hybridization, polymerase chain reaction (PCR), and reverse transcriptase-PCR, important techniques for the detection of BRAF V600E mutation and BRAF-KIAA1549 fusion, characteristic molecular alterations in pilocytic astrocytomas.

Magnetic Resonance Spectroscopy for Prediction of Grades of Diffusely Infiltrating Intracranial Astrocytomas

Objective Gliomas, the most frequent primary brain tumors, have various grades, among which grade II, III, and IV are diffusely infiltrating astrocytomas. As therapeutic approaches and outcome differ considerably, depending on the grade of these tumors, prediction is important regarding outcome. Magnetic resonance spectroscopy (MRS) can be of help in understanding of the biochemical changes of pathological state to study, monitor, predict grading and outcome of gliomas.

Materials and Methods All the 30 patients in the study with intracranial diffusely infiltrating astrocytoma had MRS study using 1.5 Tesla MR scanner. The study population was divided into three groups on the basis of the grades of the tumor according to histopathology. Mean height of choline (Ch), N-acetyl aspartate (NAA), creatine (Cr) peak, and choline/creatine (Ch/Cr) ratio was documented. Mean value of each variable among three grades was analyzed and compared with analysis of variance (ANOVA) test (F-test).

Results There was positive relationship regarding Ch/Cr ratio among astrocytomas grade II to IV and the result was significant (p = 0.047). A positive relationship of Ch peak was also observed for grade II to IV astrocytoma, though the result was not significant (p = 0.578). The result was nonsignificant for NAA (p = 0.696) and Cr (p = 0.740) peak also.

Conclusion We recommend Ch/Cr ratio to be considered as a dependable MRS data to comment on low- or high-grade astrocytomas. MRS can be done as a routine investigation in the developing countries for astrocytomas where other facilities are less accessible for reliable prediction and counseling.

Adult brainstem glioma: a multicentre retrospective analysis of 47 Italian patients

BACKGROUND AND PURPOSE

Adult brainstem gliomas are rare primary brain tumours with heterogeneous clinical course. The low frequency of these tumours makes it difficult to achieve high-quality evidence regarding prognostic factors, adequate therapeutic approach and outcome in such patients.

METHODS

In this retrospective study, we analysed clinical, radiological, molecular, prognostic and therapeutic factors in a series of 47 histologically proven adult brainstem gliomas recruited over a 20-year period (1998-2018).

RESULTS

Twenty-two patients were male, 25 female with median age of 39 years. The tumour involved one brainstem segment in 20 cases and 2 or more segments in 27. Contrast enhancement was reported in 28 cases. Surgical procedures included biopsy in 26 cases and partial/total resection in the remaining 21. Histological diagnosis was of low-grade glioma in 23 patients, high-grade glioma in 22 and non-diagnostic in 2 cases. Data regarding molecular biology were available for 22 patients. Median overall survival was 35 months, in particular 16 months in high-grade glioma and 84 months in low-grade glioma. At univariate analysis, tumour grade was the only factor with a statistically significant impact on survival time (p = 0,003), whereas younger age, better performance status and total/subtotal resection showed a trend to more prolonged survival. This study also confirms safety of biopsy/surgery in adult brainstem glioma patients and shows a clear trend to a more frequent assessment of molecular biology data.

CONCLUSIONS

Further prospective multicentre efforts, and hopefully clinical trials, are necessary to improve outcome in this neglected glioma patient population.

Pre- and Post-Surgical Dysphagia in Adults with Tumors of the Posterior Fossa: A Prospective Blinded Study

BACKGROUND

While swallowing disorders are frequent sequela following posterior fossa tumor (PFT) surgery in children, data on dysphagia frequency, severity, and outcome in adults are lacking. The aim of this study was to investigate dysphagia before and after surgical removal of PFT. Additionally, we tried to identify clinical predictors for postsurgical swallowing disorders. Furthermore, this study explored the three-month outcome of dysphagic patients.

METHODS

In a cohort of patients undergoing PFT surgery, dysphagia was prospectively assessed pre- and postoperatively using fiberoptic endoscopic evaluation of swallowing. Patients with severe dysphagia at discharge were re-evaluated after three months. Additionally, clinical and imaging data were collected to identify predictors for post-surgical dysphagia.

RESULTS

We included 26 patients of whom 15 had pre-operative swallowing disorders. After surgery, worsening of pre-existing dysphagia could be noticed in 7 patients whereas improvement was observed in 2 and full recovery in 3 subjects. New-onset dysphagia after surgery occurred in a minority of 3 cases. Postoperatively, 47% of dysphagic patients required nasogastric tube feeding. Re-evaluation after three months of follow-up revealed that all dysphagic patients had returned to full oral intake.

CONCLUSION

Dysphagia is a frequent finding in patients with PFT already before surgery. Surgical intervention can infer a deterioration of impaired swallowing function placing affected patients at temporary risk for aspiration. In contrast, surgery can also accomplish beneficial results resulting in both improvement and full recovery. Overall, our findings show the need of early dysphagia assessment to define the safest feeding route for the patient.

Surgical management of primary and secondary pilocytic astrocytoma of the cerebellopontine angle (in adults and children) and review of the literature

Glial tumors in the cerebellopontine angle (CPA) are uncommon and comprise less than 1% of CPA tumors. We present four cases of pilocytic astrocytoma of the CPA (PA-CPA) that were treated in our department. Patients who received surgical treatment for PA-CPA from January 2004 to December 2019 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. Patients were evaluated for initial symptoms, pre- and postoperative facial nerve function and cochlear function, complications, and recurrence rate by reviewing surgical reports, patient documents, neuroradiological data, and follow-up data. We identified four patients with PA-CPA out of about 1500 CPA lesions (~ 0.2%), which were surgically treated in our department in the last 16 years. Of the four patients, three were male, and one was a female patient. Two were adults, and two were children (mean age 35 years). A gross total resection was achieved in three cases, and a subtotal resection was attained in one case. Two patients experienced a moderate facial palsy immediately after surgery (House–Brackmann grade III). In all cases, the facial function was intact or good (House–Brackmann grades I–II) at the long-term follow-up (mean follow-up 4.5 years). No mortality occurred during follow-up. Three of the patients had no recurrence at the latest follow-up (mean latest follow-up 4.5 years), while one patient had a slight recurrence. PA-CPA can be safely removed, and most complications immediately after surgery resolve in the long-term follow-up.

Outcomes of presumed malignant glioma treated without pathological confirmation: a retrospective, single-center analysis

Background

Tissue diagnosis is essential in the usual management of high-grade glioma. In rare circumstances, due to patient preference, performance status, comorbidities, or tumor location, biopsy is not feasible. Sometimes a biopsy is nondiagnostic. Many neuro-oncology clinics have patients like this, but these patients' outcomes and responses to treatment are not known.

Methods

We retrospectively reviewed records from adult patients diagnosed with presumed high-grade glioma of the brain without definitive pathology, diagnosed between 2004 and 2016. We recorded several clinical variables including date of first diagnostic imaging and date of death.

Results

We identified 61 patients and subclassified them to brainstem glioma (n = 32), supratentorial presumed glioblastoma (n = 24), presumed thalamic diffuse midline glioma (n = 2), gliomatosis cerebri (n = 2), and cerebellar glioma (n = 1). Most brainstem glioma patients had no biopsy because of tumor location. Supratentorial presumed glioblastoma patients had no biopsy predominantly because of comorbidities. Median survival, from first diagnostic imaging, was 3.2 months (95% CI: 2.9 to 6.3 months) in the supratentorial glioblastoma group and 18.5 months (95% CI: 13.0 to 44.1 months) in the brainstem group. Treatment with radiation or chemotherapy did not alter the median survival of the supratentorial glioblastoma group (hazard ratio 1.41, uncorrected P = .5).

Conclusions

Patients with imaging diagnoses of high-grade glioma have similar, if not worse, survival than those with pathological confirmation. Based on these uncontrolled data, it is unclear how effective radiation or chemotherapy is in this population.

Long Noncoding RNA LINC00467 Promotes Glioma Progression through Inhibiting P53 Expression via Binding to DNMT1

Purpose: This study aimed to investigate whether long noncoding RNA (lncRNA) LINC00467 could regulate proliferative and invasive abilities of glioma cells via p53 and DNA methyltransferase 1 (DNMT1), so as to participate in the occurrence and progression of glioma. Methods: LINC00467 expression in glioma was analyzed by GEPIA database and LINC00467 expression in glioma cell lines was detected by qRT-PCR. The regulatory effects of LINC00467 and p53 on proliferative, invasive capacities and cell cycle were conducted by CCK-8 and EdU assays, transwell assay and flow cytometry, respectively. The binding conditions between LINC00467, DNMT1 and p53 were determined by RNA immunoprecipitation (RIP) and Chromatin immunoprecipitation (ChIP) assays. Western blot was conducted to determine whether LINC00467 could regulate p53 in glioma cells. Finally, rescue experiments were carried out to evaluate whether LINC00467 regulates proliferative and invasive abilities of glioma cells through p53. Results: The expression of LINC00467 was significantly up-regulated in tumor samples than that in normal samples, which was not correlated with patient survival time. Besides, expression of LINC00467 was higher in glioma cells than that of negative control cells. Upregulation of LINC00467 promoted proliferative and invasive abilities, and accelerated cell cycle in G0/G1 phase of U87 and LN229 cells. The results of RIP and ChIP assays demonstrated that LINC00467 could bind to DNMT1 and inhibit p53 expression. Overexpression of p53 partially reversed the enhancement of LINC00467 on proliferative and invasive abilities of glioma cells. Conclusion: These results indicated that high expression of LINC00467 could promote proliferative and invasive abilities of glioma cells through targeting inhibition of p53 expression by binding to DNMT1.

Risk Factors for Early Mortality Among Patients with Glioma: A Population-Based Study

OBJECTIVE

The present study evaluated the early death and factors associated with early mortality in patients with glioma.

METHODS

The data used for analysis in the present study was extracted from the Surveillance, Epidemiology, and End Results data set.

RESULTS

A total of 58,700 patients with glioma were enrolled in the present study. The proportion of patient death within 1 month and 3 months after the diagnosis was 9.24% and 19.15% for all patients, respectively. The factors significantly associated with death within 1 month after tumor resection on multivariate analysis included age at diagnosis, year of diagnosis, tumor location, histological features, tumor size, and the absence of gross total resection, radiotherapy, and chemotherapy. We also observed similar findings in the evaluation of the factors associated with 3-month mortality.

CONCLUSION

The early deaths rates, including 1 and 3 months after tumor resection in patients with glioma, have decreased slightly during the previous 40 years. The risk factors for early mortality included advanced age, male sex, tumor located in the lateral ventricle, cerebellum, or brainstem, receipt of biopsy only, no chemotherapy or radiotherapy, and specific histopathological types.

The role of radiation and chemotherapy in adult patients with high-grade brainstem gliomas: results from the National Cancer Database

INTRODUCTION

Surgical resection of high-grade brainstem gliomas is challenging and treatment mostly involves radiation and chemotherapy. In this study, we utilized registry data to determine prognostic features and impact of chemotherapy and radiation on overall survival.

METHODS

The National Cancer Database was queried from 2006 to 2015 for adult cases with histologically confirmed high-grade brainstem glioma. Covariates including patient demographics, comorbidities, tumor characteristics and treatment parameters were captured. Multivariable Cox proportional hazards regression was performed to identify predictors of survival.

RESULTS

A total of 422 patients were analyzed. Most patients (66.6%) underwent postoperative radiation with chemotherapy, 9.2% underwent radiation alone, while the remaining had no postoperative treatment (24.2%). Overall median survival was 9.8 months (95% CI 8.8-12). Survival was longer (p < 0.001) in the radiation + chemotherapy group (median: 14.2 months, 95% CI 11.7-17.1) compared to radiation alone (median: 5.7 months, 95% CI 3.7-12) and no postoperative treatment (median: 1.8 months, 95% CI 1.4-4) groups. In multivariable analysis, increasing age was associated with worse survival (HR: 1.87, 95% CI 1.47-2.37, p < 0.001), whereas radiation + chemotherapy was associated with lower mortality compared to radiation alone (HR: 0.67, 95% CI 0.46-0.98, p = 0.038). In subgroup analysis, postoperative chemotherapy with radiation was associated with significant survival benefit compared to radiation alone for grade IV (HR: 0.46, 95% CI 0.28-0.76, p = 0.003), but not for grade III tumors (HR: 0.87, 95% CI 0.48-1.58, p = 0.65).

CONCLUSION

Analysis from a national registry illustrated the effectiveness of radiation with chemotherapy for adult patients with high-grade brainstem gliomas, particularly grade IV. Further research should identify specific patient profiles and molecular subgroups that are more likely to benefit from multimodality therapy.

Tectal gliomas: assessment of malignant progression, clinical management, and quality of life in a supposedly benign neoplasm

OBJECTIVE Tectal gliomas constitute a rare and inhomogeneous group of lesions with an uncertain clinical course. Because these supposedly benign tumors are frequently followed up by observation over many years, the authors undertook this analysis of their own case series in an effort to demonstrate that the clinical course is highly variable and that there is a potential for a progressive biology. METHODS Clinical data analysis of 23 cases of tectal glioma (involving 9 children and 14 adults) was performed retrospectively. Radiographic data were analyzed longitudinally and MR images were evaluated for tumor volume, contrast enhancement, and growth progression. Quality of life was assessed using the EORTC BN20 and C30 questionnaires during follow-up in a subgroup of patients. RESULTS The patients' mean age at diagnosis was 29.2 years. The main presenting symptom at diagnosis was hydrocephalus (80%). Six patients were treated by primary tumor resection (26.1%), 3 patients underwent biopsy followed by resection (13.1%), and 3 patients underwent biopsy only (13.1%). For additional treatment of hydrocephalus, 14 patients (60.9%) received shunts and/or endoscopic third ventriculostomy. Radiographic tumor progression was observed in 47.9% of the 23 cases. The mean time between diagnosis and growth progression was 51.5 months, and the mean time to contrast enhancement was 69.7 months. Histopathological analysis was obtained in 12 cases (52.2%), resulting in 5 cases of high-grade glioma (3 cases of glioblastoma multiforme [GBM], grade IV, and 2 of anaplastic astrocytoma, grade III), 5 cases of pilocytic astrocytoma, 1 diffuse astrocytoma, and 1 ganglioglioma. Malignant progression was observed in 2 cases, with 1 case progressing from a diffuse astrocytoma (grade II) to a GBM (grade IV) within a period of 13 years. Quality-of-life measurements demonstrated distinct functional deficits compared to a healthy sample as well as glioma control cohorts. CONCLUSIONS Analysis of this case series shows that a major subpopulation of tectal gliomas show progression and malignant transformation in children as well as in adolescents. These tumors therefore cannot be considered inert lesions and require histological confirmation and close follow-up. Quality-of-life questionnaires show that tectal glioma patients might benefit from special psychological support in emotional, social, and cognitive functionality.

Association between extent of resection on survival in adult brainstem high-grade glioma patients

BACKGROUND

Brainstem high-grade gliomas (HGG) are rare lesions with aggressive behavior that pose significant treatment challenges. The operative use of brainstem safe entry zones has made such lesions surgically accessible, though the benefits of aggressive resection have been unclear. This study aimed to clarify the survival in adult patients.

METHODS

We utilized the SEER database (1973-2015) to analyze the association between survival and demographic data, tumor characteristics, and treatment factors in adult patients with brainstem HGGs. Patients without surgical intervention were excluded. Overall survival (OS) was analyzed using univariable and multivariable Cox regression.

RESULTS

Our dataset included a total of 502 brainstem HGG patients of which only those who had undergone surgical intervention were included in the analysis, totaling 103. Mean age was 42.4 ± 14.1 years with 57.2% (n = 59) male. Median OS of the entire cohort was 11.0 months. Median OS for patients receiving biopsy, subtotal resection, and gross total resection were 8, 11, and 16 months, respectively. Age, extent of resection, and radiation therapy were selected into the multivariable model. A significant decrease in survival was seen in older patients, 50-60 years (HR = 2.77, p = 0.002) and ≥ 60 years (HR = 5.30, p < 0.001), compared to younger patients (18-30 years). Partial resection (HR = 0.32, p = 0.006) and GTR (HR = 0.24, p < 0.001) sustained survival benefits compared to patients with biopsy only. Patients receiving postoperative radiation demonstrated no survival benefit (HR = 1.57, p = 0.161) in multivariable regression.

CONCLUSIONS

While survival of brainstem HGG patients remains poor, for surgically accessible HGGs, STR and GTR were associated with a three and fourfold increase in overall survival when compared to biopsy only.

Clinical Efficacy of CyberKnife Radiosurgery for Adult Brainstem Glioma: 10 Years Experience at Tianjin CyberKnife Center and Review of the Literature

Background: Brainstem glioma is a rare brain tumor with poor prognosis and difficulty for surgical resection. We sought to retrospectively analyze and evaluate the clinical efficacy of CyberKnife for brainstem gliomas.

Methods: From 2006 to 2015, a total of 21 brainstem gliomas patients who received CyberKnife radiosurgery treatment enrolled in this study and 18 patients with follow up. CyberKnife image-guided radiosurgical system were applied consecutively with the median prescribed total dose of 26 Gy (14–33 Gy) at two to six fractions on days utilizing CyberKnife system, and the median biological equivalent doses of 59.8 Gy (33.6–76.56 Gy). The clinic pathlogical features, survival were analyzed to explore the efficacy of CyberKnife radiosurgery in treatment of brainstem glioma.

Results: With median follow-up of 54.5 months, patients with brainstem gliomas had median overall survival of 19 months, five patients still alive. The primary endpoints of the 1- and 2-year overall survival rates were 87.5 and 52.4%, respectively. During the treatment course, six patients were observed to have pseudoprogression with mass effect on MRI. Four patients developed radiation complications. Grade 2 radiation-related toxicity were observed in three patients and one patient with grade 3.

Conclusion: The efficacy of brainstem gliomas—treated with CyberKnife is efficacious with mild toxicity.

Dorsally exophytic glioblastoma of the pons

Brainstem gliomas are rare tumours in adults, accounting for only 1%-2% of all intracranial gliomas. They are recognised as a heterogeneous group, in which most are malignant tumours. Brainstem gliomas are classified into four major groups according to the growth pattern on imaging, namely diffuse, focal, exophytic and cervicomedullary. Such a classification system is also useful for surgical decision making. The exophytic variant is extremely rare having anecdoctal reports in the literature. We report the case of an adult patient affected by an exophytic glioblastoma of the pons, which was submitted to subtotal resection followed by radiation therapy and chemotherapy with a longer overall survival. To the best of our knowledge, this is the seventh adult patient reported of an exophytic brainstem glioblastoma.

Treatment of adult brainstem glioma with combined antiangiogenic therapy: a case report and literature review

Adult brainstem gliomas belong to a rare and heterogeneous group of brain tumors. The overall prognosis is poor; therapeutic options are limited, given the resistance to radiotherapy and the unclear role of chemotherapy/antiangiogenic therapy. Apatinib, a tyrosine kinase inhibitor that selectively inhibits the vascular endothelial growth factor receptor and mildly inhibits c-Kit, PDGFR-β, RET, and c-SRC, has been reported to show efficacy among some patients with malignant supratentorial gliomas. However, its effect on brainstem glioma has not been reported so far. Herein, a 66-year-old man with brainstem anaplastic astrocytoma isocitrate dehydrogenase (IDH) wild type was treated initially with combined radiotherapy, temozolomide, and apatinib. The patient achieved a complete response by MRI and continues to have an ongoing progression-free survival of over 8 months. To our knowledge, this is the first case report using apatinib to treat brainstem IDH wild-type anaplastic astrocytoma, displaying an excellent outcome. We also summarize cases of adult brainstem glioma treated with antiangiogenic therapy. Experiences using various regimens may improve understanding of this rare disease, and thus help physicians to seek more effective treatments for these patients.

Multi-Channel 3D Deep Feature Learning for Survival Time Prediction of Brain Tumor Patients Using Multi-Modal Neuroimages

High-grade gliomas are the most aggressive malignant brain tumors. Accurate pre-operative prognosis for this cohort can lead to better treatment planning. Conventional survival prediction based on clinical information is subjective and could be inaccurate. Recent radiomics studies have shown better prognosis by using carefully-engineered image features from magnetic resonance images (MRI). However, feature engineering is usually time consuming, laborious and subjective. Most importantly, the engineered features cannot effectively encode other predictive but implicit information provided by multi-modal neuroimages. We propose a two-stage learning-based method to predict the overall survival (OS) time of high-grade gliomas patient. At the first stage, we adopt deep learning, a recently dominant technique of artificial intelligence, to automatically extract implicit and high-level features from multi-modal, multi-channel preoperative MRI such that the features are competent of predicting survival time. Specifically, we utilize not only contrast-enhanced T1 MRI, but also diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI), for computing multiple metric maps (including various diffusivity metric maps derived from DTI, and also the frequency-specific brain fluctuation amplitude maps and local functional connectivity anisotropy-related metric maps derived from rs-fMRI) from 68 high-grade glioma patients with different survival time. We propose a multi-channel architecture of 3D convolutional neural networks (CNNs) for deep learning upon those metric maps, from which high-level predictive features are extracted for each individual patch of these maps. At the second stage, those deeply learned features along with the pivotal limited demographic and tumor-related features (such as age, tumor size and histological type) are fed into a support vector machine (SVM) to generate the final prediction result (i.e., long or short overall survival time). The experimental results demonstrate that this multi-model, multi-channel deep survival prediction framework achieves an accuracy of 90.66%, outperforming all the competing methods. This study indicates highly demanded effectiveness on prognosis of deep learning technique in neuro-oncological applications for better individualized treatment planning towards precision medicine.

Pediatric Brainstem Gliomas: A Retrospective Study of 180 Patients from the SEER Database

BACKGROUND/AIMS

Large population-based studies are needed to assess the epidemiology and survival risk factors associated with pediatric brainstem gliomas. This retrospective study explores factors that may influence survival in this population.

METHODS

Utilizing the SEER database, the authors retrospectively assessed survival in histologically confirmed brainstem gliomas in patients aged 17 and younger. Survival was described with Kaplan-Meyer curves and multivariate regression analysis.

RESULTS

This analysis of 180 cases showed that age (hazard ratio [HR] 1.04, 95% CI 0.96-1.14, p = 0.34), non-white race (HR 1.00, 95% CI 0.35-2.85 p > 0.99), distant or invasive extension of the tumor (HR 0.4, 95% CI 0.08-2.53, p = 0.37), and radiation therapy (HR 1.27, 95% CI 0.52-3.11, p = 0.61) were not associated with decreased survival. High-grade tumor status (HR 8.64, 95% CI 3.49-21.41, p < 0.001) was associated with decreased survival. Partial resection (HR 0.11, 95% CI 0.04-0.30, p < 0.001) and gross-total resection (HR 0.03, 95% CI 0.01-0.14, p < 0.001) were associated with improved survival.

CONCLUSIONS

High-grade brainstem gliomas have a worse prognosis. Early diagnosis and surgery appear to be associated with improved survival, while the role of radiation is unclear.