Directionally non-rotating electric field therapy delivered through implanted electrodes as a glioblastoma treatment platform: A proof-of-principle study.

Background: While directionally rotating tumor-treating fields (TTF) therapy has garnered considerable clinical interest in recent years, there has been comparatively less focus on directionally non-rotating electric field therapy (dnEFT). Methods: We explored dnEFT generated through customized electrodes as a glioblastoma therapy in in vitro and in vivo preclinical models. The effects of dnEFT on tumor apoptosis and microglia/macrophages in the tumor microenvironment were tested using flow-cytometric and qPCR assays. Results: In vitro, dnEFT generated using a clinical-grade spinal cord stimulator showed antineoplastic activity against independent glioblastoma cell lines. In support of the results obtained using the clinical-grade electrode, dnEFT delivered through a customized, 2-electrode array induced glioblastoma apoptosis. To characterize this effect in vivo, a custom-designed 4-electrode array was fabricated such that tumor cells can be implanted into murine cerebrum through a center channel equidistant from the electrodes. After implantation with this array and luciferase-expressing murine GL261 glioblastoma cells, mice were randomized to dnEFT or placebo. Relative to placebo-treated mice, dnEFT reduced tumor growth (measured by bioluminescence) and prolonged survival (median survival gain of 6.5 days). Analysis of brain sections following dnEFT showed a notable increase in the accumulation of peritumoral macrophage/microglia with increased expression of M1 genes (IFNγ, TNFα, and IL-6) and decreased expression of M2 genes (CD206, Arg, and IL-10) relative to placebo-treated tumors. Conclusions: Our results suggest therapeutic potential in glioblastoma for dnEFT delivered through implanted electrodes, supporting the development of a proof-of-principle clinical trial using commercially available deep brain stimulator electrodes.

Role of immunotherapy in treatment refractory chordomas: review of current evidence.

Introduction: Chordomas are aggressive tumors that are thought to arise from remnants of the embryological notochord. They can arise along the ventromedial aspect of the sacrum, mobile spine, and clivus-with most cases occurring in the sacrum or skull base. Despite surgery and radiation, chordomas often progress and become refractory to further treatment. The high recurrence rate of chordomas has created an urgent need to develop new systemic treatment options. Recent case reports and clinical trials have highlighted the use of immunotherapy for refractory chordomas. In this review, we summarize the results of these studies and discuss the potential role of immunotherapy for chordomas. Methods: The PUBMED database was queried for studies mentioning both "Chordoma" and "Immunotherapy." All case series and case reports that involved administration of an immunotherapy for chordoma were included. Additional studies that were found during literature review were added. ClinicalTrials.Gov was queried for studies mentioning both "Chordoma" and "Immunotherapy." The final cohort consisted of all clinical trials that utilized immunotherapy for chordomas of any location. Results: Eight case reports and series detailing the use of immunotherapy for treatment refractory chordoma were identified. Most patients received immunotherapy targeting the PD-1/PD-L1 interaction, and two patients received therapy targeting this interaction along with the tyrosine kinase inhibitor pazopanib. One patient received a vaccine derived from autologous tumor cells, and one patient received a viral vector that downregulated the effect of TGF-beta. One clinical trial utilized a brachyury vaccine in conjunction with standard of care radiotherapy. Conclusions: Immunotherapy for chordoma is a promising area of investigation with increasing, but small, numbers of case series and clinical trials. Despite challenges in patient accrual, future directions in chordoma immunotherapy may lie in vaccine-based therapies and immune checkpoint inhibitors. Understanding chordoma heterogeneity and microenvironment will likely elucidate important chordoma features that will inform future clinical trial design.

Sagittal balance in sitting and standing positions: A systematic review of radiographic measures.

Background: Sagittal imbalance can be caused by various etiologies and is among the most important indicators of spinal deformity. Sagittal balance can be restored through surgical intervention based on several radiographic measures. The purpose of this study is to review the normal parameters in the sitting position, which are not well understood and could have significant implications for non-ambulatory patients. Methods: A systematic review was performed adhering to PRISMA Guidelines. Using R-software, the weighted means and 95% confidence intervals of the radiographic findings were calculated using a random effect model and significance testing using unpaired t-tests. Results: 10 articles with a total of 1066 subjects reported radiographic measures of subjects with no spinal deformity in the sitting and standing position. In the healthy individual, standing sagittal vertical axis -16.8°was significantly less than sitting 28.4° (p < 0.0001), while standing lumbar lordosis 43.3°is significantly greater than sitting 21.3° (p < 0.0001). Thoracic kyphosis was not significantly different between the two groups (p = 0.368). Standing sacral slope 34.3° was significantly greater than sitting 19.5° (p < 0.0001) and standing pelvic tilt 14.0° was significantly less than sitting 33.9° (p < 0.0001). Conclusions: There are key differences between standing and sitting postures, which could lead to undue stress on surgical implants and poor outcomes, especially for non-ambulatory populations. There is a need for more studies reporting sitting and standing radiographic measures in different postures and spinal conditions.

Spontaneous Spinal Hematoma in Patients Using Antiplatelets and Anticoagulants: A Systematic Review.

BACKGROUND: Spontaneous spinal hematoma (SSH) is a debilitating complication in patients taking either antiplatelet (AP) or anticoagulation (AC) medications. SSH is rare and, therefore, a systematic review is warranted to re-examine and outline trends, clinical characteristics, and outcomes associated with SSH formation. METHODS: PubMed, EMBASE, Scopus, and Web-of-Science were searched. Studies reporting clinical data of patients with SSH using AC medications were included. In addition, clinical studies meeting our a priori inclusion criteria limited to SSH were further defined in quality through risk bias assessment. RESULTS: We included 10 studies with 259 patients' pooled data post-screening 3083 abstracts. Within the cohort (n = 259), the prevalence of idiopathic, nontraumatic SSH with concomitant treatment with AC medications was greater 191 (73.75%) compared with AP treatment (27%). The lumbar spine was the most common site of hematoma (41.70%), followed by the cervical (22.01%) and thoracic (8.49%) spine. Most patients had surgical intervention (70.27%), and 29.73% had conservative management. The pooled data suggest that immediate diagnosis and intervention are the best prognostic factors in clinical outcomes. American Spinal Injury Association grading at initial symptom onset and post-treatment showed the greatest efficacy in symptomatic relief (87.64%) and return of motor and sensory symptoms (39.19%). CONCLUSIONS: Our review suggested that AC medications were related to SSH in most patients (74%), followed by APs (27%) and combined ACs + APs (1.9%). We recommend prompt intervention, a high suspicion for patients with neurologic deficits and diagnostic imaging before intervention to determine a case-specific treatment plan.

Comparison meta-analysis of intraoperative MRI-guided needle biopsy versus conventional stereotactic needle biopsies.

Background: MRI-guided needle biopsy (INB) is an emerging alternative to conventional frame-based or frameless stereotactic needle biopsy (SNB). Studies of INB have been limited to select case series, and comparative studies between INB and SNB remain a missing gap in the literature. We performed a meta-analysis to compare INB and SNB literature in terms of diagnostic yield, surgical morbidity and mortality, tumor size, and procedural time. Methods: We identified 36 separate cohorts in 26 studies of SNB (including both frameless and frame-based biopsies, 3374 patients) and 27 studies of INB (977 patients). Meta-regression and meta-analysis by proportions were performed. Results: Relative to publications that studied SNB, publications studying INB more likely involved brain tumors located in the eloquent cerebrum (79.4% versus 62.6%, P = 0.004) or are smaller in maximal diameter (2.7 cm in INB group versus 3.6 cm in the SNB group, P = .032). Despite these differences, the pooled estimate of diagnostic yield for INB was higher than SNB (95.4% versus 92.3%, P = .026). The pooled estimate of surgical morbidity was higher in the SNB group (12.0%) relative to the INB group (6.1%) (P = .004). Mortality after the procedure was comparable between INB and SNB (1.7% versus 2.3%, P = .288). Procedural time was statistically comparable at 90.3 min (INB) and 103.7 min (SNB), respectively (P = .526). Conclusions: Our meta-analysis indicates that, relative to SNB, INB is more often performed for the challenging, smaller-sized brain tumors located in the eloquent cerebrum. INB is associated with lower surgical morbidity and improved diagnostic yield.

Influence of Body Mass Index on Surgical and Patient Outcomes for Cervical Spine Surgery.

STUDY DESIGN: Secondary analysis of prospectively collected registry. OBJECTIVE: We aim to investigate the effects of body mass index (BMI) on postsurgical cervical spine surgery outcomes and identify a potential substratification of obesity with worse outcomes. SUMMARY OF BACKGROUND DATA: The impact of BMI on cervical spine surgery is unknown, with controversial outcomes for patients high and low BMI. METHODS: The cervical spine Quality Outcomes Database was queried for a total of 10,381 patients who underwent single-stage cervical spine surgery. Patients were substratified into 6 groups based on BMI. Surgical outcomes, complications, hospitalization outcomes, and patient-reported outcomes for each cohort, including modified Japanese Orthopedic Association Score, Numeric Rating Scale arm pain, Numeric Rating Scale neck pain, Neck Disability Index, and EuroQol Health Survey, were assessed. Univariate analysis was performed for 3- and 12-month follow-up after surgical intervention. RESULTS: Obese patients (class I, II, and III) requiring spine surgery were statistically younger than nonobese patients and had higher rates of diabetes compared with normal BMI patients. The surgical length was found to be longer for overweight and all classes of obese patients ( P < 0.01). Class III obese patients had higher odds of postoperative complications. Patients with class II and III obesity had lower odds of achieving optimal modified Japanese Orthopedic Association Score at 3 months [OR = 0.8 (0.67-0.94), P < 0.01, OR = 0.68 (0.56-0.82), P < 0.001, respectively] and 12 months [OR = 0.82 (0.68-0.98), P = 0.03, OR = 0.79 (0.64-0.98), P = 0.03, respectively]. CONCLUSIONS: This study investigates the relationship between substratified BMI and postoperative outcomes of cervical spine surgery. Class II and III obese patients have substantially greater risk factors and poor outcomes postoperatively. In addition, low BMI also presents unique challenges for patients. Further research is needed for comprehensive analysis on outcomes of cervical spine surgery after correcting BMI.

Neurosurgery residency match for international medical graduates in the United States.

OBJECTIVE: Training of international medical graduates (IMGs) offers opportunities for the US neurosurgery community to engage the global talent pool and impact national and international healthcare. Here, the authors analyzed the time trend of IMGs matching into US neurosurgery programs and identified potential opportunities for enhancing IMG engagement. METHODS: The authors analyzed the National Resident Matching Program (NRMP) match results, NRMP program director (PD) surveys, and applicant surveys from 2013 to 2022. Regression methods were used to analyze time trends. RESULTS: Between 2013 and 2022, the number of US neurosurgery residency positions increased by 17.6% (from 204 to 240). During this period, the percentage of IMGs matching into neurosurgery increased from 3.5% to 7%, translating into a 6.8% increase in the likelihood of a successful IMG match per year (95% CI 0.3%-13.8%, p = 0.042). The likelihoods of a successful match for US MDs and IMGs scoring > 260 on the USMLE Step 1 were > 90% and approximately 55%, respectively. In PD surveys, approximately 90% of PDs indicated that they seldom/never interview or rank IMGs. In terms of factors that influenced the PD decision for interviewing/ranking, IMGs are disadvantaged in several categories, including the ability to secure an audition elective/rotation, and proper letters of recommendation, as well as the influence of the culture on the preconceived perception of poor interpersonal skills. CONCLUSIONS: The number of IMGs matching successfully in neurosurgery has increased marginally during the past decade. The authors outline the challenges that IMGs encounter in this process and suggest strategies for considerations of IMG training in NRMP-associated institutions.

Comparison of Stereotactic Radiosurgery and Hypofractionated Radiosurgery for Vestibular Schwannomas: A Meta-Analysis of Available Literature.

BACKGROUND: Stereotactic radiosurgery (SRS) and recently, hypofractionated radiosurgery (hSRS) are increasingly utilized as treatment for vestibular schwannomas (VS). We performed a meta-analysis of literature comparing these modalities. METHODS: The PubMed database of articles was searched for studies that compared SRS and hSRS in patients with VS. Variables analyzed include tumor control, hearing preservation, facial nerve preservation, trigeminal nerve preservation, and total complications. Heterogeneity across the studies was gauged using Higgins's inconsistency index. Funnel plots and Egger's regression intercept test were used to address the publication bias. RESULTS: Thirteen studies that satisfied the search criteria were selected for meta-analysis. The studies identified in our study included 353 SRS and 511 hSRS-treated patients. Analysis of heterogeneity showed that hSRS is employed for relatively larger tumor sizes in comparison to SRS. Pooled meta-analysis estimates showed no significant differences between SRS and hSRS in terms of tumor control (odds ratio [OR], 0.620; 95% confidence interval [CI], 0.21-1.86, P = 0.39), hearing preservation (OR, 1.07; 95% CI, 0.59-1.93, P = 0.83), facial nerve preservation (OR, 0.53; 5% CI, 0.23-1.21, P = 0.13), or trigeminal nerve preservation (OR, 0.67; 95% CI, 0.24-1.89, P = 0.49) at a mean follow-up of 39 months. Statistically significant heterogeneity was found across the studies only for tumor diameter (Higgins's inconsistency index = 65.69%, P = 0.003) but not for other variables. CONCLUSIONS: Meta-analysis of thirteen studies comparing SRS and hSRS as treatment for VS showed comparable tumor control, hearing preservation, facial nerve preservation, and trigeminal nerve preservation.

Increased risk for ex-vacuo ventriculomegaly with leukoencephalopathy (EVL) in whole brain radiation therapy and repeat radiosurgery treated brain metastasis patients.

INTRODUCTION: Cerebral atrophy with leukoencephalopathy is a known morbidity after whole brain radiation therapy (WBRT), resulting in ex-vacuo ventriculomegaly with leukoencephalopathy (EVL). Here we studied the correlation between WBRT, stereotactic radiosurgery (SRS), and risk for EVL in brain metastases patients. METHODS: In a retrospective study, we identified 195 patients (with 1,018 BM) who underwent SRS for BM (2007-2017) and had > 3 months of MRI follow-up. All patients who underwent ventriculoperitoneal shunting were excluded. Cerebral atrophy was measured by ex-vacuo-ventriculomegaly, defined based on Evans' criteria. Demographic and clinical variables were analyzed using logistic regression models. RESULTS: Ex-vacuo ventriculomegaly was observed on pre-radiosurgery imaging in 29.7% (58/195) of the study cohort. On multivariate analysis, older age was the only variable associated with pre-radiosurgery ventriculomegaly. Of the 137 patients with normal ventricular size before radiosurgery, 27 (19.7 %) developed ex-vacuo ventriculomegaly and leukoencephalopathy (EVL) post-SRS. In univariate analysis, previous whole brain radiation therapy was the main factor associated with increased risk for developing EVL (OR = 5.08, p < 0.001). In bivariate models that included prior receipt of WBRT, both the number of SRS treatments (OR = 1.499, p = 0.025) and WBRT (OR = 11.321, p = 0.003 were independently associated with increased EVL risk. CONCLUSIONS: While repeat radiosurgery contributes to the risk of EVL in BM patients, this risk is ∼20-fold lower than that associated with WBRT.

Prognostic Factors and Treatment Impact on Overall Survival in Adult Craniopharyngioma.

OBJECTIVE: To examine the demographics, tumor characteristics, treatments, and clinical outcomes of a large adult craniopharyngioma population. METHODS: The 2004-2018 National Cancer Database was queried to investigate adult patients with craniopharyngioma. Univariable and multivariable Cox hazard ratio analysis was conducted to analyze the overall survival (OS) impact of demographic and clinical variables. RESULTS: A total of 666 adult patients with craniopharyngioma were identified with a mean age of 51 years (standard deviation 16 years). On multivariable analysis, independent of demographic and clinical variables, increased age, uninsured status, Medicaid, Medicare, Charlson-Deyo Comorbidity Index of 2, and tumor size greater than 40 mm were independently associated with worse OS. There was no significant difference in survival between histologic subtypes. Gross total resection (GTR) (hazard ratio [HR] 0.602, 95% confidence interval [CI] 0.384-0.942, P = 0.026) and subtotal resection (STR) with adjuvant radiotherapy (HR 0.316, 95% CI 0.140-0.710, P = 0.005) were independently associated with improved OS. GTR with radiotherapy trended towards improved OS (HR 0.601, 95% CI 0.334-1.083, P =0.090), but STR alone and radiotherapy alone demonstrated no significant difference in survival compared with no treatment on multivariable analysis. Kaplan-Meier survival models demonstrated improved survival with GTR, GTR + radiation therapy, and STR + radiation therapy. Patients undergoing endoscopic resection had significantly lower GTR rates and greater rates of adjuvant radiotherapy compared with open approaches but no difference in OS. CONCLUSION: Adult patients with craniopharyngioma who underwent GTR or STR with adjuvant radiotherapy had significantly improved overall survival. Endoscopic approaches had lower rates of GTR but no difference in OS.

Modern Management of Complex Tympanojugular Paragangliomas: Systematic Review and Meta-Analysis.

OBJECTIVE: Tympanojugular paragangliomas (TJPs) are slow-growing tumors arising within the middle ear or jugular foramen. The development of modified skull base approaches and the increasing use of stereotactic radiosurgery have provided more modern techniques in the management of TJPs. Several factors dictating approach selection, and resulting clinical outcomes have been inconsistently described. METHODS: A systematic review of the literature describing modern management of complex TJPs was performed and summarized. A random-effects meta-analysis was performed to describe the rate of tumor control, complications, and symptom improvement in patients undergoing radiosurgery or surgical resection. RESULTS: Nineteen studies were identified with a total of 852 TJP patients. A minority (153 patients) underwent radiosurgery while 699 underwent surgery. On meta-analysis, there was a 3.5% (95% confidence interval [CI]: 0.5%-6.4%) tumor growth rate following radiosurgery and 3.9% (95% confidence interval [CI]: 1.8%-6.0%) recurrence rate in surgical resection, with no significant moderator effect between the 2 groups (P = 0.9046). Complication rate for radiosurgery was 7.6% (95% CI: 2.8%-12.4%), differing significantly from surgical complication rates of 29.6% (95% CI: 17.1-42.0%, P = 0.0418). CONCLUSIONS: Stereotactic radiosurgery and surgical resection for TJPs have similar rates of tumor recurrence. Radiation is associated with less risk and lower morbidity, yet there is comparably modest reduction of the tumor size. In sum, the data suggest that radiosurgery is a reasonable management option for patients with minimal symptoms who are high risk for surgery. Microsurgical resection should be reserved for patients with lower cranial neuropathies or those who have failed radiation treatment.

Racial disparities in recommendations for surgical resection of primary brain tumours: a registry-based cohort analysis.

BACKGROUND: Disparities in treatment and outcomes disproportionately affect minority ethnic and racial populations in many surgical fields. Although substantial research in racial disparities has focused on outcomes, little is known about how surgeon recommendations can be influenced by patient race. The aim of this study was to investigate racial and socioeconomic disparities in the surgical management of primary brain tumors. METHODS: In this registry-based cohort study, we used data from the Surveillance, Epidemiology, and End Results (SEER) database (1975-2016) and the American College of Surgeons National Cancer Database (NCDB) in the USA for independent analysis. Adults (aged ≥20 years) with a new diagnosis of meningioma, glioblastoma, pituitary adenoma, vestibular schwannoma, astrocytoma, and oligodendroglioma, with information on tumour size and surgical recommendation were included in the analysis. The primary outcome of this study was the odds of a surgeon recommending against surgical resection at diagnosis of primary brain neoplasms. This outcome was determined using multivariable logistic regression with clinical, demographic, and socioeconomic factors. FINDINGS: This study included US national data from the SEER (1975-2016) and NCDB (2004-17) databases of adults with a new diagnosis of meningioma (SEER n=63 674; NCDB n=222 673), glioblastoma (n=35 258; n=104 047), pituitary adenoma (n=27 506; n=87 772), vestibular schwannoma (n=11 525; n=30 745), astrocytoma (n=5402; n=10 631), and oligodendroglioma (n=3977; n=9187). Independent of clinical and demographic factors, including insurance status and rural-urban continuum code, Black patients had significantly higher odds of recommendation against surgical resection of meningioma (adjusted odds ratio 1·13, 95% CI 1·06-1·21, p<0·0001), glioblastoma (1·14, 1·01-1·28, p=0·038), pituitary adenoma (1·13, 1·05-1·22, p<0·0001), and vestibular schwannoma (1·48, 1·19-1·84, p<0·0001) when compared with White patients in the SEER dataset. Additionally, patients of unknown race had significantly higher odds of recommendation against surgical resection for pituitary adenoma (1·80, 1·41-2·30, p<0·0001) and vestibular schwannoma (1·49, 1·10-2·04, p=0·011). Performing a validation analysis using the NCDB dataset confirmed these significant results for Black patients with meningioma (1·18, 1·14-1·22, p<0·0001), glioblastoma (1·19, 1·12-1·28, p<0·0001), pituitary adenoma (1·21, 1·16-1·25, p<0·0001), and vestibular schwannoma (1·19, 1·04-1·35, p=0·0085), and indicated and indicated that the findings are independent of patient comorbidities. When further restricted to the most recent decade in SEER, these inequities held true for Black patients, except those with glioblastoma (meningioma [1·18, 1·08-1·28, p<0·0001], pituitary adenoma [1·20, 1·09-1·31, p<0·0001], and vestibular schwannoma [1·54, 1·16-2·04, p=0·0031]). INTERPRETATION: Racial disparities in surgery recommendations in the USA exist for patients with primary brain tumours, independent of potential confounders including clinical, demographic, and select socioeconomic factors. Further studies are needed to understand drivers of this bias and enhance equality in surgical care. FUNDING: None.

Functional virus-specific memory T cells survey glioblastoma.

Glioblastoma multiforme (GBM) is among the most aggressive, treatment-resistant cancers, and despite standard of care surgery, radiation and chemotherapy, is invariably fatal. GBM is marked by local and systemic immunosuppression, contributing to resistance to existing immunotherapies that have had success in other tumor types. Memory T cells specific for previous infections reside in tissues throughout the host and are capable of rapid and potent immune activation. Here, we show that virus-specific memory CD8 + T cells expressing tissue-resident markers populate the mouse and human glioblastoma microenvironment. Reactivating virus-specific memory T cells through intratumoral delivery of adjuvant-free virus-derived peptide triggered local immune activation. This delivery translated to antineoplastic effects, which improved survival in a murine glioblastoma model. Our results indicate that virus-specific memory T cells are a significant part of the glioblastoma immune microenvironment and may be leveraged to promote anti-tumoral immunity.

Racial disparity in recommendation for surgical resection of skull base chondrosarcomas: A Surveillance, Epidemiology, and End Results (SEER) analysis.

INTRODUCTION: There is increased appreciation of racial disparities in the delivery of neurosurgical care. Here, we explore whether race influences surgical recommendations in the management of skull base chondrosarcomas. METHODS: We identified 493 patients with skull base chondrosarcoma using the Surveillance, Epidemiology, and End Results (SEER) registry (November 2017 submission). Regression analyses were performed to identify demographic variables associated with recommendation against surgery. Univariate and multivariate cox proportional hazards models were used for survival analysis. RESULTS: In a univariate analysis, we found that the African-American race was associated with an increased likelihood of surgeon recommendation against surgery (OR = 4.416, 95% CI = 1.893-10.302, p = 0.001). This association remained robust in the multivariate model that controlled for other covariates, including age of diagnosis (OR = 5.091, 95% CI = 2.127-12.187, p < 0.001). For patients who received a recommendation against surgery, the likelihood of dying from non-chondrosarcoma causes was comparable between Caucasian and African-American patients, suggesting that the prevalence and severity of medical conditions that increase the risk of death were comparable between these cohorts (HR = 0.466, 95% CI = 0.057-3.802, p = 0.475). The likelihood of dying from chondrosarcoma was comparable between Caucasian and African-American patients who underwent surgery (HR = 0.982, 95% CI = 0.353-2.732, p = 0.973), suggesting absence of race-specific surgical benefits. CONCLUSION: We identified a racial disparity against African-Americans in recommendations for surgical resection of skull base chondrosarcomas.

Clinical outcomes as a function of the number of samples taken during stereotactic needle biopsies: a meta-analysis.

BACKGROUND: Stereotactic needle biopsy remains the cornerstone for tissue diagnosis for tumors located in regions of the brain that are difficult to access through open surgery. OBJECTIVE: We perform a meta-analysis of the literature to examine the relation between number of samples taken during biopsy and diagnostic yield, morbidity and mortality. METHODS: We identified 2416 patients from 28 cohorts in studies published in PubMed database that studied stereotactic needle biopsies for tumor indications. Meta-analysis by proportions and meta-regression analyses were performed. RESULTS: On meta-analysis, the morbidity profile of the published needle biopsy studies clustered into three groups: studies that performed < 3 samples (n = 8), 3-6 samples (n = 13), and > 6 samples during biopsy (n = 7). Pooled estimates for biopsy related morbidity were 4.3%, 16.3%, and 17% for studies reporting < 3, 3-6, and > 6 biopsy samples, respectively. While these morbidity estimates significantly differed (p < 0.001), the diagnostic yields reported for studies performing < 3 biopsies, 3-6 samples, and > 6 samples were comparable. Pooled estimates of diagnostic yield for these three groups were 90.4%, 93.8%, and 88.1%, respectively. Mortality did not significantly differ between studies reporting differing number of samples taken during biopsy. CONCLUSIONS: Our meta-analysis suggests that morbidity risk in needle biopsy is non-linearly associated with the number of samples taken. There was no association between the number of biopsies taken, and diagnostic yield or mortality.

PI3Kγ inhibition suppresses microglia/TAM accumulation in glioblastoma microenvironment to promote exceptional temozolomide response.

Precision medicine in oncology leverages clinical observations of exceptional response. Toward an understanding of the molecular features that define this response, we applied an integrated, multiplatform analysis of RNA profiles derived from clinically annotated glioblastoma samples. This analysis suggested that specimens from exceptional responders are characterized by decreased accumulation of microglia/macrophages in the glioblastoma microenvironment. Glioblastoma-associated microglia/macrophages secreted interleukin 11 (IL11) to activate STAT3-MYC signaling in glioblastoma cells. This signaling induced stem cell states that confer enhanced tumorigenicity and resistance to the standard-of-care chemotherapy, temozolomide (TMZ). Targeting a myeloid cell restricted an isoform of phosphoinositide-3-kinase, phosphoinositide-3-kinase gamma isoform (PI3Kγ), by pharmacologic inhibition or genetic inactivation disrupted this signaling axis by reducing microglia/macrophage-associated IL11 secretion in the tumor microenvironment. Mirroring the clinical outcomes of exceptional responders, PI3Kγ inhibition synergistically enhanced the anti-neoplastic effects of TMZ in orthotopic murine glioblastoma models. Moreover, inhibition or genetic inactivation of PI3Kγ in murine glioblastoma models recapitulated expression profiles observed in clinical specimens isolated from exceptional responders. Our results suggest key contributions from tumor-associated microglia/macrophages in exceptional responses and highlight the translational potential for PI3Kγ inhibition as a glioblastoma therapy.

Epidermal growth factor receptor as a molecular determinant of glioblastoma response to dopamine receptor D2 inhibitors.

BACKGROUND: There are ongoing clinical trials exploring the efficacy of dopamine receptor D2 (DRD2) inhibition against glioblastomas, the most common primary brain tumor. Here we examine potential molecular determinants of this efficacy. METHODS: The Cancer Genome Atlas glioblastoma database and other published mRNA profiles were used to analyze the DRD2 and epidermal growth factor receptor (EGFR) expression pattern. In vitro and in vivo responses to DRD2 inhibitors were determined using patient-derived xenograft (PDX) glioblastoma models. Immunohistochemical studies were performed on clinically annotated glioblastoma samples derived from patients treated with ONC201. RESULTS: Analysis of clinical glioblastoma specimens derived from independent patient cohorts revealed an inverse correlation between EGFR and DRD2 mRNA expression, with implication that signaling mediated by these proteins shares overlapping functions. In independent panels of PDX glioblastoma lines, high EGFR expression was associated with poor in vitro and in vivo response to DRD2 inhibitors, including haloperidol and ONC201. Moreover, ectopic expression of a constitutively active EGFR, variant (v)III, suppressed glioblastoma sensitivity to ONC201. DRD2 expression positively correlated with expression of rate-limiting enzymes for dopamine synthesis as well as dopamine secretion, suggesting contribution of autocrine DRD2 signaling. Analysis of specimens from patients treated with ONC201 (n = 15) showed an inverse correlation between the intensity of EGFR staining and clinical response. The median overall survival for patients with high and low EGFR staining was 162 and 373 days, respectively (0.037). CONCLUSIONS: High EGFR expression is a determinant of poor glioblastoma response to DRD2. This finding should inform future clinical trial designs.

Synchronous Occurrence of Colloid Cyst With Intracranial Ossifying Fibromyxoid Tumor Masquerading as Meningioma.

Ossifying fibromyxoid tumor (OFMT) is a rare fibro-osseous neoplasm. We present a case highlighting the occurrence of an intracranial OFMT masquerading as meningioma on imaging in a 46-year-old gentleman. Brain imaging revealed an extra-axial calcified lesion along the left cerebellar convexity appearing hypointense on T1- and T2-weighted MRI sequences with no post-contrast enhancement, suggestive of a meningioma. An intraventricular colloid cyst was also noted. The lesion, which was presumed to be meningioma, and the colloid cyst were resected in two subsequent operative settings. Histopathological examination of the calcified lesion confirmed the findings of an OFMT. This report aims to inform the physician about intracranial OFMT mimicking meningioma on imaging. In addition, since multiple brain tumors are not very common, the surgeon should always have a suspicion should there be any heterogeneous and peculiar radiological and histopathological characteristics.