Thalamic Glioblastoma: Clinical Presentation, Management Strategies, and Outcomes

Endoscopic Supracerebellar Infratentorial Transpineal Approach for Posterior-Medial Thalamic Lesions: Surgical Technique and Clinical Experience

BACKGROUND AND OBJECTIVES

Accessing lesions in the posterior-medial thalamus can be challenging because of their deep location and intricate neurovascular anatomy. This study aims to describe the techniques and feasibility of the endoscopic supracerebellar infratentorial transpineal approach for treating posterior-medial thalamus lesions.

METHODS

We reviewed and analyzed the clinical outcomes and endoscopic surgical experience of 11 patients with posterior-medial thalamic lesions. The first 4 cases used the endoscopic midline supracerebellar infratentorial transpineal approach, whereas the subsequent 7 cases used the endoscopic contralateral paramedian supracerebellar infratentorial transpineal approach. All cases involved the upward transposition of the pineal gland to access the posterior-medial thalamus. The extent of resection and the endoscopic techniques were the main focus of analysis. Neurological examinations and MRI/computed tomography follow-up were conducted for 3-12 months after surgery.

RESULTS

The pathology of the group included 6 gliomas, 1 cavernous malformation, 1 inflammation, 1 melanoma, and 2 hematomas. All 11 patients achieved gross total resection (6 patients, 54.5%) or subtotal resection (5 patients, 45.5%) with no new neurological deficits. Most patients (9 patients, 81.8%) experienced improvement in Karnofsky Performance Status after surgery. Postoperative hydrocephalus occurred in 2 patients (18.2%) and was relieved by endoscopic third ventriculostomy.

CONCLUSION

The endoscopic supracerebellar infratentorial transpineal approach is an effective approach for removing posterior-medial thalamic lesions that require access through the third ventricle surfaces of the thalamus. The endoscopic contralateral paramedian supracerebellar infratentorial transpineal approach provides a more superior and lateral view of the posterior-medial thalamic lesions.

Prognostic nomogram models for predicting survival probability in elderly glioblastoma patients

PURPOSE

To investigate the prognostic factors of survival and develop a predictive nomogram model for elderly GBM patients.

METHODS

Elderly patients (> = 65 years) with histologically diagnosed GBM were extracted from the SEER database. Survival analysis of overall survival (OS) was performed by Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses were used to determine independent prognostic factors and these factors were used to further construct the nomogram model.

RESULTS

A total of 9068 elderly GBM patients (5122 males and 3946 females) were included, with a median age of 72 years (65-96 years). All patients were divided randomly into the training group (n = 6044) and the validation group (n = 3024) by a ratio of 2:1. Cox regression analyses on OS showed eight independent prognostic factors (race, age, tumor side, tumor size, metastasis, surgery, radiotherapy, and chemotherapy) in the training cohort. Also, seven variables (except for race) were identified on CSS in the training group. By comprising these variables, the nomogram models on OS and CSS for predicting the 6-month, 1-year, and 2-year survival probability were constructed and exhibited moderate consistency, respectively. Then, they could be validated well in the validation cohort and by C-index, time-dependent ROC curve, calibration plot, and DCA curve.

CONCLUSIONS

Nomogram models on OS and CSS could provide an applicable tool to predict the survival probability and provide clinical references regarding treatment strategies and prognosis.

Newly Diagnosed Adult Basal Ganglia Gliomas Treated With Laser Interstitial Thermal Therapy: A Comparative Cohort With Needle Biopsy

BACKGROUND

Few cytoreductive surgical tools are available for newly diagnosed basal ganglia gliomas. Current reports showed high associated morbidity and mortality. Given their deep localization, laser interstitial thermal therapy (LITT) is still a rare indication. Moreover, few reports account for which of the available options have better outcomes.

OBJECTIVE

To retrospectively analyze our experience with LITT and compare its safety, feasibility, and efficacy with needle biopsy for the management of adult basal ganglia gliomas.

METHODS

Twenty-two patients with gliomas from the midline (e.g. thalamus and lenticular nucleus) managed with either LITT/biopsy or needle biopsy from 2015 to 2021 were included. Records regarding location, diagnosis, Karnofsky Performance Score, length of hospital stay, preoperative lesion and ablation volume, perioperative complications, and data of adjuvant treatment were collected. Overall survival was evaluated with Kaplan-Meier analysis.

RESULTS

Seven patients had LITT, and 15 underwent biopsy. The overall mean age was 60.9 years (25-82 years). The average tumor volume in the former was 16.99 cm 3 and 17.65 cm 3 in the latter. No postsurgical complications were found in the LITT group, and 1 patient had a postsurgical hemorrhage after biopsy. The mean overall survival was 20.28 ± 9.63 months in the LITT group, which was greater but not statistically significant than in the biopsy group (13.85 ± 4.48 months; P = .78).

CONCLUSION

Our results show that laser ablation may be both feasible and safe in adult basal ganglia gliomas. Given the lack of safe cytoreductive treatment options, LITT should be considered as a valid choice for these patients.

Impact of age and gender on glioblastoma onset, progression, and management

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, while its frequency in pediatric patients is 10-15%. For this reason, age is considered one of the major risk factors for the development of GBM, as it correlates with cellular aging phenomena involving glial cells and favoring the process of tumor transformation. Gender differences have been also identified, as the incidence of GBM is higher in males than in females, coupled with a worse outcome. In this review, we analyze age- and gender- dependent differences in GBM onset, mutational landscape, clinical manifestations, and survival, according to the literature of the last 20 years, focusing on the major risk factors involved in tumor development and on the mutations and gene alterations most frequently found in adults vs young patients and in males vs females. We then highlight the impact of age and gender on clinical manifestations and tumor localization and their involvement in the time of diagnosis and in determining the tumor prognostic value.

Modeling of intracranial tumor treating fields for the treatment of complex high-grade gliomas

Increasing the intensity of tumor treating fields (TTF) within a tumor bed improves clinical efficacy, but reaching sufficiently high field intensities to achieve growth arrest remains challenging due in part to the insulating nature of the cranium. Using MRI-derived finite element models (FEMs) and simulations, we optimized an exhaustive set of intracranial electrode locations to obtain maximum TTF intensities in three clinically challenging high-grade glioma (HGG) cases (i.e., thalamic, left temporal, brainstem). Electric field strengths were converted into therapeutic enhancement ratios (TER) to evaluate the predicted impact of stimulation on tumor growth. Concurrently, conventional transcranial configurations were simulated/optimized for comparison. Optimized intracranial TTF were able to achieve field strengths that have previously been shown capable of inducing complete growth arrest, in 98-100% of the tumor volumes using only 0.54-0.64 A current. The reconceptualization of TTF as a targeted, intracranial therapy has the potential to provide a meaningful survival benefit to patients with HGG and other brain tumors, including those in surgically challenging, deep, or anatomically eloquent locations which may preclude surgical resection. Accordingly, such an approach may ultimately represent a paradigm shift in the use of TTFs for the treatment of brain cancer.

Are Thalamic Intrinsic Lesions Operable? No-Man's Land Revisited by the Analysis of a Large Retrospective, Mono-Institutional, Cohort

Thalamic gliomas represent a heterogeneous subset of deep-seated lesions for which surgical removal is advocated, although clear prognostic factors linked to advantages in performance status or overall survival are still lacking. We reviewed our Institutional Cancer Registry, identifying patients who underwent surgery for thalamic gliomas between 2006 and 2020. Associations between possible prognostic factors such as tumor volume, grade, the extent of resection and performance status (PS), and overall survival (OS) were evaluated using univariate and multivariate survival analyses. We found 56 patients: 31 underwent surgery, and 25 underwent biopsy. Compared to biopsy, surgery resulted positively associated with an increase in the OS (hazard ratio, HR, at multivariate analysis 0.30, 95% confidence interval, CI, 0.12-0.75). Considering the extent of resection (EOR), obtaining GTR/STR appeared to offer an OS advantage in high-grade gliomas (HGG) patients submitted to surgical resection if compared to biopsy, although we did not find statistical significance at multivariate analysis (HR 0.53, 95% CI 0.17-1.59). Patients with a stable 3-month KPS after surgery demonstrated to have a better prognosis in terms of OS if compared to biopsy (multivariate HR 0.17, 95% CI, 0.05-0.59). Age and histological grades were found to be prognostic factors for this condition (p = 0.04 and p = 0.004, respectively, chi-square test). Considering the entire cohort, p53 positivity (univariate HR 2.21, 95% CI 1.01-4.82) and ATRX positivity (univariate HR 2.69, 95% CI 0.92-7.83) resulted associated with a worse prognosis in terms of OS. In this work, we demonstrated that surgery aimed at tumor resection might offer a stronger survival advantage when a stable 3-month KPS after surgery is achieved.

miR-3059-3p Regulates Glioblastoma Multiforme Radiosensitivity Enhancement through the Homologous Recombination Pathway of DNA Repair

Background

Glioblastoma multiforme (GBM) is one of the most deadly and recalcitrant illnesses of the neurocentral nervous system in humans. MicroRNAs (miRNAs) are a class of noncoding RNAs that play important roles in the regulation of gene expression and biological processes, including radiosensitivity. In this study, we demonstrated the relationship between miR-3059-3p and radiation in GBM.

Materials and Methods

Radioresistant (RR) cells were obtained by exposing GBM8401 cells to 80 Gy radiation in 20 weekly 4 Gy fractions. miR-3059-3p mRNA and DNA replication helicase/nuclease 2 (DNA2) protein expressions were detected using real-time polymerase chain reaction and immunoblotting. Using flow cytometry, colony formation and apoptosis were identified using miR-3059-3p mimic, miR-3059-3p inhibitor, DNA2 siRNA, and DNA2 plasmid. Immunoblotting was used to detect DNA repair proteins.

Results

Low levels of miR-3059-3p and high levels of DNA2 were observed in RR cells. Colony formation and apoptosis assays revealed that miR-3059-3p targeted DNA2 to regulate radioresistance. Immunoblotting revealed that miR-3059-3p regulated the homologous recombination (HR) pathway (Rad51 and Rad52) but not the nonhomologous end joining pathway (ku70 and ku80).

Conclusion

Downregulation of DNA2 via miR-3059-3p enhanced the radiosensitivity of GBM cells through the inhibition of the HR pathway.

Risk Factors for Early Hydrocephalus on Post Unilateral Thalamic Tumor Resection

Objective

The outcome of surgical treatment for thalamic tumors is poor. Hydrocephalus is one of the most frequent postoperative complications after unilateral thalamic tumor resection. This study examined the relationship between surgical approaches, pathological grade, image characteristics, preoperative complications, extent of resection, and incidence of postoperative hydrocephalus.

Methods

The study retrospectively reviewed clinical data from 80 patients who underwent resection of thalamic tumors between 2015 and 2021. Data on patient survival and disease progression status were obtained retrospectively to calculate overall survival (OS) and progression free survival (PFS).

Results

No patients died during the perioperative period and two patients suffered postoperative coma. Tumors were totally resected in 44 cases (55 %), subtotally resected in 21 cases (26.25 %), and partially resected in 15 cases (18.75 %). Thirty-five cases of hydrocephalus occurred within 1 month after operation(43.75%). Surgical approaches associated with hydrocephalus were as follows: hydrocephalus occurred in seven cases after trans-frontal lateral ventricle approach for tumor resection (62.9%), in 17 cases after through parieto-occipital transventricular approach tumor resection (43.58%), and in one case after trans-frontal lateral ventricle approach for tumor resection + third ventriculostomy (7.1%). Postoperative muscle strength decrease occurred in 41 patients (51.25%). Longer PFS and OS were correlated with degree of resection in patients with thalamic glioblastoma (P < 0.05) and had no relationship with hydrocephalus.

Conclusion

Surgical treatment of thalamic tumors is an effective therapeutic method. The incidence of postoperative hydrocephalus is not associated with tumor size, degree of tumor enhancement, peritumoral edema, tumor invasion, midline crossing, and pathological grade. The incidence of postoperative hydrocephalus was higher in patients with preoperative hydrocephalus and low resection degree, and lower in patients with endoscopic third ventriculostomy. The risk of early postoperative hydrocephalus in thalamic tumors is high. Intraoperative third ventriculostomy could reduce the incidence of early postoperative hydrocephalus. PFS and OS were longer in patients with thalamic glioblastoma with a high resection degree (P < 0.05) and were not associated with hydrocephalus.

Adult H3K27M mutated thalamic glioma patients display a better prognosis than unmutated patients

BACKGROUND

Adult thalamic gliomas are a rare entity whose management is challenging for physicians. The aim of this study is to describe the characteristics and prognostic factors of thalamic gliomas in adult patients.

METHODS

We retrospectively analyzed the clinical, neuro-radiological, histological, and molecular characteristics of all cases of adult thalamic glioma in our regional center.

RESULTS

We included 38 adult patients. Median age at diagnosis was 56.5 years old (range, 24-80). Median KPS at diagnosis was 70%. Two-thirds of patients presented with tumor necrosis on MRI. Bithalamic lesions were present in four patients. The median volume of enhancement associated with lesions was relatively small (14 mm³). Two patients had undergone partial surgical resection. All other patients underwent biopsy. Median PFS was 7.1 months (95% CI [3.7-10.5]) and median OS was 15.6 months (95% CI [11.7-19.6]). Among 20 patients with available tumor samples for molecular analyses, only 4 (20%) presented with H3K27M mutation. Patients with H3K27M mutation had longer survival compared to those without. Finally, we identified a long-term survivor population characterized by a younger age, no cognitive impairment, low steroid dose treatment and the presence of H3K27M mutation.

CONCLUSION

Thalamic adult glioma differs from bithalamic glioma in children with regards to its clinical, radiological and molecular profiles. Long-term survival is observed in young patients with limited symptoms and H3K27M mutation. A larger prospective cohort is needed to validate these findings.

Thalamic gliomas in adults: a systematic review of clinical characteristics, treatment strategies, and survival outcomes

PURPOSE

Thalamic gliomas are rare neoplasms that pose significant surgical challenges. The literature is limited to single-institution retrospective case series. We systematically review the literature and describe the clinical characteristics, treatment strategies, and survival outcomes of adult thalamic gliomas.

METHODS

Relevant articles were identified on PubMed, Scopus, and Cochrane databases. Papers containing cases of adult thalamic gliomas with clinical outcome data were included. A comprehensive review of clinical characteristics and survival analysis was conducted.

RESULTS

We included 25 studies comprising 617 patients. The median age was 45 years (male = 58.6%). Glioblastoma was the most frequent histological type (47.2%), and 82 tumors were H3 K27M-mutant. Motor deficit was the most common presenting symptom (51.8%). Surgical resection was performed in 69.1% of cases while adjuvant chemotherapy and radiotherapy were administered in 56.3% and 72.6%, respectively. Other treatments included laser interstitial thermal therapy, which was performed in 15 patients (2.4%). The lesion laterality (P = 0.754) and the surgical approach (P = 0.111) did not correlate with overall survival. The median progression-free survival was 9 months, and the overall two-year survival rate was 19.7%. The two-year survival rates of low-grade and high-grade thalamic gliomas were 31.0% and 16.5%, respectively. H3 K27M-mutant gliomas showed worse overall survival (P = 0.017).

CONCLUSION

Adult thalamic gliomas are associated with poor survival. Complete surgical resection is associated with improved survival rates but is not always feasible. H3 K27M mutation is associated with worse survival and a more aggressive approach should be considered for mutant neoplasms.

Glioblastoma with deep supratentorial extension is associated with a worse overall survival

Glioblastoma (GBM) with deep-supratentorial extension (DSE) involving the thalamus, basal ganglia and corpus collosum, poses significant challenges for clinical management. In this study, we present our outcomes in patients who underwent resection of supratentorial GBM with associated involvement of deep brain structures. We conducted a retrospective review of patients who underwent resection of GBM at our institution between 2012 and 2018. A total of 419 patients were included whose pre-operative MRI scans were reviewed. Of these, 143 (34.1%) had GBM with DSE. There were similar rates of IDH-1 mutation (9% versus 7.6%, p = 0.940) and MGMT methylation status (35.7% versus 45.2%, p = 0.397) between the two cohorts. GBM patients without evidence of DSE had higher rates of radiographic gross total resection (GTR) compared to those with DSE: 70.6% versus 53.1%, respectively (p = 0.002). The presence of DSE was not associated with decreased progression-free survival (PFS) compared to patients without DSE (mean 7.24 ± 0.97 versus 8.89 ± 0.76 months, respectively; p = 0.276), but did portend a worse overall survival (OS) (mean 10.55 ± 1.04 versus 15.02 ± 1.05 months, respectively; p = 0.003). There was no difference in PFS or OS amongst DSE and non-DSE patients who underwent GTR, but patients who harbored DSE and underwent subtotal resection had worse OS (mean 8.26 ± 1.93 versus 12.96 ± 1.59 months, p = 0.03). Our study shows that GBM patients with DSE have lower OS compared to those without DSE. This survival difference appears to be primarily related to the limited surgical extent of resection owing to the neurological deficits that may be incurred with involvement of eloquent deep brain structures.

Laser Interstitial Thermal Therapy in the Treatment of Thalamic Brain Tumors: A Case Series

BACKGROUND

Surgical options for patients with thalamic brain tumors are limited. Traditional surgical resection is associated with a high degree of morbidity and mortality. Laser interstitial thermal therapy (LITT) utilizes a stereotactically placed laser probe to induce thermal damage to tumor tissue. LITT provides a surgical cytoreduction option for this challenging patient population. We present our experience treating thalamic brain tumors with LITT.

OBJECTIVE

To describe our experience and outcomes using LITT on patients with thalamic tumors.

METHODS

We analyzed 13 consecutive patients treated with LITT for thalamic tumors from 2012 to 2017. Radiographic, clinical characteristics, and outcome data were collected via review of electronic medical records.

RESULTS

Thirteen patients with thalamic tumors were treated with LITT. Most had high-grade gliomas, including glioblastoma (n = 9) and anaplastic astrocytoma (n = 2). The average tumor volume was 12.0 cc and shrank by 42.9% at 3 mo. The average hospital stay was 3.0 d. Median ablation coverage as calculated by thermal damage threshold (TDT) lines was 98% and 95% for yellow (>43°C for >2 min) or blue (>10 min), respectively. Median disease-specific progression-free survival calculated for 8 patients in our cohort was 6.1 mo (range: 1.1-15.1 mo). There were 6 patients with perioperative morbidity and 2 perioperative deaths because of intracerebral hematoma.

CONCLUSION

LITT is a feasible treatment for patients with thalamic tumors. LITT offers a cytoreduction option in this challenging population. Patient selection is key. Close attention should be paid to lesion size to minimize morbidity. More studies comparing treatment modalities of thalamic tumors need to be performed.

Evolution of surgical attitudes to paediatric thalamic tumours: the alder hey experience

PURPOSE

Attitudes to surgery for paediatric thalamic tumours have evolved due to improved preoperative imaging modalities and the advent of intraoperative MRI (iMRI) as well as enhanced understanding of tumour biology. We review the developments in our local practice over the last three decades with particular attention to the impact of iMRI.

METHODS

We identified all paediatric patients from a prospectively maintained neuro-oncology database who received surgery for a thalamic tumour (n = 30). All children were treated in a single UK tertiary paediatric neurosurgery centre between January 1991 and June 2020. Twenty patients underwent surgical resection, the remainder (10) undergoing biopsy only. Pre-operative surgical intent (biopsy versus debulking, near-total resection, or complete resection) as well as the use of iMRI were prospectively recorded. Complications recorded in clinical documentation between postoperative days 0 and 30 were retrospectively graded using a modified version of the Clavien Dindo scale. The extent of resection with respect to the pre-determined surgical aim was also recorded. Data on patient survival and disease progression status were obtained retrospectively.

RESULTS

In our series, there were 42 procedures (25 craniotomies, 17 biopsies) performed on 30 patients (17 male, with a median age of 8 at surgery). Of the 25 surgical resections performed, complete resection was achieved in 9 (36%), near-total resection in 10 (40%), and limited debulking in 6 (24%). The predetermined surgical aim was achieved or exceeded in 91.3% of cases. The proportion of craniotomies for which substantial resection was achieved, increased from 37.5 to 94.2% with use of iMRI (p = 0.014). Surgical morbidity was not associated with greater extent of surgical resection. High-grade histology is identified as the only independent significant factor influencing overall survival as calculated by Cox proportional hazards model (p = 0.006).

CONCLUSION

We note a significant change in the rate and extent of attempted resection of paediatric thalamic tumours that has developed over the last 3 decades. Use of iMRI is associated with a significant increase in substantial tumour resection surgeries. This is not associated with any significant level of surgical morbidity. Improvements in pre- and intra-operative imaging alongside better understanding of tumour biology facilitate patient selection and a surgically more aggressive approach in selected cases whilst maintaining safety and avoiding operative morbidity.

Endoscopic Third Ventriculostomy for Hydrocephalus Secondary to Extraventricular Obstruction in Thalamic Hemorrhage: A Case Series

BACKGROUND

Intracranial hemorrhage carries significant morbidity and mortality, particularly if associated with hydrocephalus. Management of hydrocephalus includes temporary external ventricular drainage, with or without shunting. Thalamic location is an independent predictor of mortality and increases the likelihood of shunt dependence.

OBJECTIVE

To determine whether endoscopic third ventriculostomy (ETV) can avoid the need for shunt placement and expedite recovery.

METHODS

We prospectively identified thalamic intracranial hemorrhage patients who developed acute hydrocephalus requiring cerebrospinal fluid diversion by extraventricular drain placement from November 2017 to February 2019. Patients who failed an extraventricular drain clamping trial were then evaluated for eligibility for an ETV procedure. Patients who underwent ETV were then followed up for the development of hydrocephalus, need for shunting, and length of stay in the intensive care unit.

RESULTS

Eight patients (7 males, 1 female) were prospectively enrolled. All patients underwent an ETV successfully. None of the patients required shunting. ETV was performed despite the presence of other factors that would have prevented shunt placement, including fever, leukocytosis, and gastrostomy tube placement. Seven patients who underwent ETV were evaluated at 3-mo follow-up and did not require shunting.

CONCLUSION

ETV is a safe and effective technique for the management of hydrocephalus resulting from an extraventricular obstruction in thalamic hemorrhage. It can avoid the need for permanent shunting in this patient population. Larger studies should be conducted to validate and further analyze this intervention.

A Unique Case of Bilateral Thalamic High-Grade Glioma in a Pediatric Patient with LI-Fraumeni Syndrome: Case Presentation and Review of the Literature

Li-Fraumeni syndrome (LFS) is a rare high-penetrance and autosomal-dominant pathological condition caused by the germline mutation of the TP53 gene, predisposing to the development of tumors from pediatric age. We conducted a qualitative systematic review following the ENTREQ (Enhancing Transparency in Reporting the Synthesis of Qualitative Research) framework. A search was made in MEDLINE/Pubmed and MeSH Database using the terms "Li-Fraumeni" AND "pediatric high-grade glioma (HGG)", identifying six cases of HGGs in pediatric patients with LFS. We added a further case with peculiar features such as no familiar history of LFS, association of embryonal rhabdomyosarcoma and bithalamic HGG, whose immunohistochemical profile was accurately defined by Next Generation Sequencing. Knowledge synthesis and case analysis grounded the discussion about challenges in the management of this pathology in pediatric age.

Maximal surgical resection and adjuvant surgical technique to prolong the survival of adult patients with thalamic glioblastoma

The importance of maximal resection in the treatment of glioblastoma (GBM) has been reported in many studies, but maximal resection of thalamic GBM is rarely attempted due to high rate of morbidity and mortality. The purpose of this study was to investigate the role of surgical resection in adult thalamic glioblastoma (GBM) treatment and to identify the surgical technique of maximal safety resection. In case of suspected thalamic GBM, surgical resection is the treatment of choice in our hospital. Biopsy was considered when there was ventricle wall enhancement or multiple enhancement lesion in a distant location. Navigation magnetic resonance imaging, diffuse tensor tractography imaging, tailed bullets, and intraoperative computed tomography and neurophysiologic monitoring (transcranial motor evoked potential and direct subcortical stimulation) were used in all surgical resection cases. The surgical approach was selected on the basis of the location of the tumor epicenter and the adjacent corticospinal tract. Among the 42 patients, 19 and 23 patients underwent surgical resection and biopsy, respectively, according to treatment strategy criteria. As a result, the surgical resection group exhibited a good response with overall survival (OS) (median: 676 days, p < 0.001) and progression-free survival (PFS) (median: 328 days, p < 0.001) compared with each biopsy groups (doctor selecting biopsy group, median OS: 240 days and median PFS: 134 days; patient selecting biopsy group, median OS: 212 days and median PFS: 118 days). The surgical resection groups displayed a better prognosis compared to that of the biopsy groups for both the O6-methylguanine-DNA methyltransferase unmethylated (log-rank p = 0.0035) or methylated groups (log-rank p = 0.021). Surgical resection was significantly associated with better prognosis (hazard ratio: 0.214, p = 0.006). In case of thalamic GBM without ventricle wall-enhancing lesion or multiple lesions, maximal surgical resection above 80% showed good clinical outcomes with prolonged the overall survival compared to biopsy. It is helpful to use adjuvant surgical techniques of checking intraoperative changes and select the appropriate surgical approach for reducing the surgical morbidity.

Early outcomes of supratentorial cranial surgery for tumor resection in older patients

With longevity increasing in the United States, more older individuals are presenting with supratentorial brain tumors. Despite improved perioperative management, there is persistent disparity in surgical resection rates among patients aged 65 years or older. We aim to assess the effects of advanced age (≥65 years) on 30-day outcomes in patients with supratentorial tumors who underwent craniotomy for supratentorial tumor resection. Data obtained in adults who underwent supratentorial tumor resections was extracted from the prospectively-collected American College of Surgeons: National Surgical Quality Improvement Program (NSQIP; 2012-2018) database. Using multivariate regression, we compared odds of major and minor complications; prolonged length-of-stay (LOS); discharge anywhere other than home; and 30-day readmission, reoperation, and mortality rates between patients aged 18-64 years (the control cohort) and those 65-74 years or ≥75 years of age. Of the 14,234 patients who underwent craniotomy for supratentorial tumors and met inclusion criteria, 30.7% were ≥65 years of age; 71.4% of these were 65-74 years and 28.6% were ≥75 years old. Compared to the control group, both older subpopulations had more medical comorbidities. Both older subgroups had increased odds of major complications and prolonged LOS relative to the control group. Older patients had greater odds of mortality at 30 days. Advanced age, defined as ≥65 years, was significantly associated with higher odds of complications, prolonged LOS, and mortality within the 30-day post- operative period after adjusting for potential confounders. Age is one important consideration when prospectively risk-stratifying patients to minimize and mitigate suboptimal perioperative outcomes.

Adult diffuse midline gliomas: Clinical, radiological, and genetic characteristics

Diffuse midline gliomas (DMGs) are a diffuse glioma subtype arising from midline brain structures. It is predominantly a disease of childhood; however, it can also occur in adults. Adult DMG has not been previously well described. The aim of this study was to define the characteristics of adult DMG. We described and analyzed the clinical, radiological, and genetic alterations of 9 adult DMGs and compared them with those of 257 non-midline adult high-grade IDH-WT gliomas. The median age of all patients was 38-years old (23-68-years). Most common symptoms were headache, motor/sensory deficit, ataxia, cranial nerve deficit, and confusion. Tumor locations were brainstem (44.5%), thalamus (22.2%), pineal region (22.2%), spinal cord (22.2%), and cerebellum (11.1%). Six-patients (66.7%) were H3 K27M-WT and three (33.3%) were H3 K27M-mutant. In addition to H3 K27M mutations, TP53 gene (55.5%), CDKN2A/B and TERTp (33.3%), PDGFRA (33.3%), PIK3CA, PTEN, KDR, NF1, and MYC (22.2%) were the most frequently mutated genes. Neither IDH1/IDH2 nor EGFR alterations were present. Compared to non-midline high-grade glioma, adult DMG patients were younger (38 vs 61 years, p < 0.001) and lacked EGFR-alterations (0/9 vs 123/257, p = 0.004). The median survival of DMG and non-midline high-grade gliomas was 19 and 18 months respectively (p = 0.964). Our data support that adult DMGs have different oncogenic drivers compared to non-midline high-grade gliomas. Regardless of H3 K27M mutation status, neither of the nine adult DMG cases demonstrated IDH1/IDH2 or EGFR alterations. Larger multi-institutional studies are needed to further characterize the biology of this rare type of diffuse glioma in adults.

Microneurosurgical removal of thalamic lesions: surgical results and considerations from a large, single-surgeon consecutive series

OBJECTIVE

The object of this study was to present the surgical results of a large, single-surgeon consecutive series of patients who had undergone transcisternal (TCi) or transcallosal-transventricular (TCTV) endoscope-assisted microsurgery for thalamic lesions.

METHODS

This is a retrospective study of a consecutive series of patients harboring thalamic lesions and undergoing surgery at one institution between February 2007 and August 2019. All surgical and patient-related data were prospectively collected. Depending on the relationship between the lesion and the surgically accessible thalamic surfaces (lateral ventricle, velar, cisternal, and third ventricle), one of the following surgical TCi or TCTV approaches was chosen: anterior interhemispheric transcallosal (AIT), posterior interhemispheric transtentorial subsplenial (PITS), perimedian supracerebellar transtentorial (PeST), or perimedian contralateral supracerebellar suprapineal (PeCSS). Since January 2018, intraoperative MRI has also been part of the protocol. The main study outcome was extent of resection. Complete neurological examination took place preoperatively, at discharge, and 3 months postoperatively. Descriptive statistics were calculated for the whole cohort.

RESULTS

In the study period, 92 patients underwent surgery for a thalamic lesion: 81 gliomas, 6 cavernous malformations, 2 germinomas, 1 metastasis, 1 arteriovenous malformation, and 1 ependymal cyst. In none of the cases was a transcortical approach adopted. Thirty-five patients underwent an AIT approach, 35 a PITS, 19 a PeST, and 3 a PeCSS. The mean follow-up was 38 months (median 20 months, range 1-137 months). No patient was lost to follow-up. The mean extent of resection was 95% (median 100%, range 21%-100%), and there was no surgical mortality. Most patients (59.8%) experienced improvement in their Karnofsky Performance Status. New permanent neurological deficits occurred in 8 patients (8.7%). Early postoperative (< 3 months after surgery) problems in CSF circulation requiring diversion occurred in 7 patients (7.6%; 6/7 cases in patients with high-grade glioma).

CONCLUSIONS

Endoscope-assisted microsurgery allows for the removal of thalamic lesions with acceptable morbidity. Surgeons must strive to access any given thalamic lesion through one of the four accessible thalamic surfaces, as they can be reached through either a TCTV or TCi approach with no or minimal damage to normal brain parenchyma. Patients harboring a high-grade glioma are likely to develop a postoperative disturbance of CSF circulation. For this reason, the AIT approach should be favored, as it facilitates a microsurgical third ventriculocisternostomy and allows intraoperative MRI to be done.

Improved survival of glioblastoma patients treated at academic and high-volume facilities: a hospital-based study from the National Cancer Database

OBJECTIVE

The present study was designed to explore the association between facility type (academic center [AC] vs non-AC), facility volume (high-volume facility [HVF] vs low-volume facility [LVF]), and outcomes of glioblastoma (GBM) treatment.

METHODS

Based on the National Cancer Database (NCDB), GBM patients were categorized by treatment facility type (non-AC vs AC) and volume [4 categories (G1-G4): < 5.0, 5.0-14.9, 15.0-24.9, and ≥ 25.0, cases/year]. HVF was defined based on the 90th percentile of annual GBM cases (≥ 15.0 cases/year). Outcomes include overall survival (OS), the receipt of surgery and adjuvant therapies, 30-day readmission/mortality, 90-day mortality, and prolonged length of inpatient hospital stay (LOS). Kaplan-Meier methods and accelerated failure time (AFT) models were applied for survival analysis, and multivariable logistic regression models were performed to compare differences in the receipt of treatment and related short-term outcomes by facility type and volume.

RESULTS

A total of 40,256 GBM patients diagnosed between 2004 and 2014 were included. Patients treated at an AC & HVF experienced the longest survival (median OS: 13.3, 11.8, 11.1, and 10.3 months; time ratio [TR]: 1.00 [Ref.], 0.96, 0.92, and 0.89; for AC & HVF, AC & LVF, non-AC & HVF, and non-AC & LVF, respectively), regardless of care transition/treatment referral. Tumor resection, radiotherapy, and chemotherapy were most frequently utilized in AC & HVF. Prolonged LOS, 30-day readmission, and 90-day mortality were decreased by 20%, 22%, and 16% (p ≤ 0.001), respectively, at AC & HVF.

CONCLUSIONS

This study provides evidence of superior outcomes when GBM patients are treated at AC and HVF. Standardization of health care across facility type and/or volume and comprehensive neuro-oncological care should be a potential goal in the management of GBM patients.

Surgical treatment and survival outcome of patients with adult thalamic glioma: a single institution experience of 8 years

PURPOSE

Given the rarity in the population with adult thalamic gliomas (ATGs), comprehensive characteristics, treatments and survival outcome are not well characterized. This study was conducted to investigate the comprehensive characteristic and treatment of ATGs and identify the prognostic factors associated with overall survival (OS).

METHODS

A retrospective analysis of newly diagnosed ATGs who underwent surgical resection consecutively was conducted. Survival analysis of OS was performed by Kaplan-Meier analysis. Cox proportional hazard model was used to investigate the possible prognostic factors associated with OS.

RESULTS

A total of 102 patients with ATG were enrolled in this study. The median age was 41 years (range 18-68 years). There were 56 (54.9%) males. Sixty-two patients (60.8%) had glioblastoma (GBM). Among these patients, 46 patients (45.1%) had GTR/NTR, 50 patients (49.0%) had STR and 6 patients (5.9%) had PR. Postoperatively, 71.6% of these patients received adjuvant therapy. The median OS was 13.6 months (range 1 week-75 months). COX regression analysis revealed that ATG patients with longer duration of symptoms (p = 0.024), better pre-KPS (p = 0.045), maximal resection (p = 0.013), or lower tumor grade (p = 0.002) had longer OS, and these predictors are considered as independent prognostic factors. Survival analysis showed that ATGs with GTR/NTR plus chemoradiotherapy had significant OS advantage compared with other treatment regimens.

CONCLUSIONS

This study comprehensively summarized the characteristics, treatments and survival outcomes of ATGs in the largest sample size. Maximal surgical resection can bring survival benefit. Combined-modality therapy regimen of GTR/NTR plus chemoradiotherapy may be better beneficial for OS than other regimens.

MGMT Expression Contributes to Temozolomide Resistance in H3K27M-Mutant Diffuse Midline Gliomas

Diffuse midline gliomas (DMGs) show resistance to many chemotherapeutic agents including temozolomide (TMZ). Histone gene mutations in DMGs trigger epigenetic changes including DNA hypomethylation, one of which is a frequent lack of O6-methyl-guanine-DNA methyltransferase (MGMT) promoter methylation, resulting in increased MGMT expression. We established the NGT16 cell line with HIST1H3B K27M and ACVR1 G328E gene mutations from a DMG patient and used this cell line and other DMG cell lines with H3F3A gene mutation (SF7761, SF8628, JHH-DIPG1) to analyze MGMT promoter methylation, MGMT protein expression, and response to TMZ. Three out of 4 DMG cell lines (NGT16, SF8628, and JHH-DIPG1) had unmethylated MGMT promoter, increased MGMT expression, and showed resistance to TMZ treatment. SF7761 cells with H3F3A gene mutation showed MGMT promoter methylation, lacked MGMT expression, and sensitivity to TMZ treatment. NGT16 line showed response to ALK2 inhibitor K02288 treatment in vitro. We confirmed in vitro that MGMT expression contributes to TMZ resistance in DMG cell lines. There is an urgent need to develop new strategies to treat TMZ-resistant DMGs.

Lateral or Medial Surgical Approaches for Thalamic Gliomas Resection?

OBJECTIVE

This study aimed to investigate the selection, safety, and prognosis of medial (transcorpus callosal) and lateral (translateral brain gyrus) approaches for adult thalamic glioma resection.

METHODS

The medical records of adult patients with thalamic glioma between March 2006 and March 2016 in Huashan Hospital were reviewed. The probabilistic map of the gliomas was shown in Montreal Neurological Institute (MNI) space, and a paralleling midline was delineated to decide the approach. The extent of resection, complications, adjuvant treatment, and survival data were analyzed. A literature review was also conducted.

RESULTS

Fifty-three patients with thalamic glioma were enrolled. Eighteen patients received tumor resection by a medial approach and 35 by a lateral approach. The probabilistic map based on 20 patients showed that 9 gliomas with ≥45% located in the medial side were treated medially and the other 11 gliomas were treated laterally. Both approaches achieved adequate extent of resection with similar morbidity. Kaplan-Meier analysis showed no significant difference of overall survival by a transcorpus callosal or translateral brain gyrus approach. Total resection (TR) or subtotal resection (STR) (P = 0.0003), radiochemotherapy (P < 0.0001), and low-grade glioma (P = 0.031) were correlated with better OS. Multivariate Cox regression analysis showed that TR/STR (P = 0.007; 95% confidence interval, 1.345-6.287) and radiochemotherapy (P < 0.0001; 95% confidence interval, 4.740-71.569) were independent prognostic factors for adult thalamic gliomas.

CONCLUSIONS

Both medial and lateral approaches are feasible and adequate for resection of thalamic gliomas. The paramidline paralleling midline crossing the genu of the internal capsule could help make the choice. TR/STR, radiochemotherapy, and low-grade glioma could benefit the prognosis.

Clinical and Molecular Characteristics of Thalamic Gliomas: Retrospective Report of 26 Cases

OBJECTIVE

Thalamic glioma is a type of midline glioma with poor outcomes. In the present study, we investigated the clinical and molecular features of thalamic gliomas in Chinese patients.

METHODS

The data from 26 patients with thalamic glioma who had undergone surgery at Shanghai Huashan Hospital from January 2011 to August 2015 were retrospectively analyzed. Various clinical and molecular factors were evaluated to explore their effects on prognosis. H3K27M mutation status and its association with relevant molecular factors were also investigated.

RESULTS

The mean age of the patients was 38.88 years, and no significant difference was found in sex. The most common initial symptoms were headaches (38.46%; 10 of 26) and motor deficits (30.77%; 8 of 26). The H3K27M mutation was identified in 12 patients, and mutant thalamic glioma showed less frequent O-6-methylguanine DNA methyltransferase (MGMT) promoter methylation compared with the wild-type group (P = 0.015; χ¹ test). Multivariate analysis showed that the H3K27M mutation was an independent unfavorable prognostic factor for overall survival. MGMT promoter unmethylation and the TP53 mutation were identified as negative prognostic factors for progression-free survival.

CONCLUSIONS

Our results revealed the clinical and molecular characteristics of thalamic glioma in China. Our data have shown the absence of MGMT promoter methylation in H3K27M mutant thalamic glioma, validating it as a hallmark of H3K27M mutant gliomas. In addition, H3K27M mutation was identified as the sole unfavorable prognostic factor on overall survival. MGMT promoter unmethylation and TP53 mutation were identified as independent prognostic factors for progression-free survival.

Challenges in cerebrospinal fluid shunting in patients with glioblastoma

Background

Cerebrospinal fluid (CSF) circulation disturbances may occur during the course of disease in patients with glioblastoma. Ventriculoperitoneal shunting has generally been recommended to improve symptoms in glioblastoma patients. Shunt implantation for patients with glioblastoma, however, presents as a complex situation and produces different problems to shunting in other contexts. Information on complications of shunting glioma patients has rarely been the subject of investigation. In this retrospective study, we analysed restropectively the course and outcome of glioblastoma-related CSF circulation disturbances after shunt management in a consecutive series of patients within a period of over a decade.

Methods

Thirty of 723 patients with histopathologically-confirmed glioblastoma diagnosed from 2002 to 2016 at the Department of Neurosurgery, Hannover Medical School, underwent shunting for CSF circulation disorders. Treatment history of glioblastoma and all procedures associated with shunt implementation were analyzed. Data on follow-up, time to progression and survival rates were obtained by review of hospital charts and supplemented by phone interviews with the patients, their relations or the primary physicians.

Results

Mean age at the time of diagnosis of glioblastoma was 43 years. Five types of CSF circulation disturbances were identified: obstructive hydrocephalus (n = 9), communicating hydrocephalus (n = 15), external hydrocephalus (n = 3), trapped lateral ventricle (n = 1), and expanding fluid collection in the resection cavity (n = 2). All patients showed clinical deterioration. Procedures for CSF diversion were ventriculoperitoneal shunt (n = 21), subduroperitoneal shunt (n = 3), and cystoperitoneal shunt (n = 2). In patients with lower Karnofsky Performance Score (KPS) (< 60), there was a significant improvement of median KPS after shunt implantation (p = 0.019). Shunt revision was necessary in 9 patients (single revision, n = 6; multiple revisions, n = 3) due to catheter obstruction, catheter dislocation, valve defect, and infection. Twenty-eight patients died due to disease progression during a median follow-up time of 88 months. The median overall survival time after diagnosis of glioblastoma was 10.18 months.

Conclusions

CSF shunting in glioblastoma patients encounters more challenge and is associated with increased risk of complications, but these can be usually managed by revision surgeries. CSF shunting improves neurological function temporarily, enhances quality of life in most patients although it is not known if survival rate is improved.

MGMT Expression Contributes to Temozolomide Resistance in H3K27M-Mutant Diffuse Midline Gliomas and MGMT Silencing to Temozolomide Sensitivity in IDH-Mutant Gliomas

Histone H3 mutations are frequently found in diffuse midline gliomas (DMGs), which include diffuse intrinsic pontine gliomas and thalamic gliomas. These tumors have dismal prognoses. Recent evidence suggests that one reason for the poor prognoses is that O⁶-methylguanine-DNA methyltransferase (MGMT) promoter frequently lacks methylation in DMGs. This review compares the epigenetic changes brought about by histone mutations to those by isocitrate dehydrogenase-mutant gliomas, which frequently have methylated MGMT promoters and are known to be sensitive to temozolomide.