Laser interstitial thermal therapy (LITT) vs. bevacizumab for radiation necrosis in previously irradiated brain metastases.

PURPOSE: Both laser interstitial thermal therapy (LITT) and bevacizumab have been used successfully to treat radiation necrosis (RN) after radiation for brain metastases. Our purpose is to compare pre-treatment patient characteristics and outcomes between the two treatment options. METHODS: Single-institution retrospective chart review identified brain metastasis patients who developed RN between 2011 and 2018. Pre-treatment factors and treatment responses were compared between those treated with LITT versus bevacizumab. RESULTS: Twenty-five patients underwent LITT and 13 patients were treated with bevacizumab. The LITT cohort had a longer overall survival (median 24.8 vs. 15.2 months for bevacizumab, p = 0.003) and trended to have a longer time to local recurrence (median 12.1 months vs. 2.0 for bevacizumab), although the latter failed to achieve statistical significance (p = 0.091). LITT resulted in an initial increase in lesional volume compared to bevacizumab (p < 0.001). However, this trend reversed in the long term follow-up, with LITT resulting in a median volume decrease at 1 year post-treatment of - 64.7% (range - 96.0% to + > 100%), while bevacizumab patients saw a median volume increase of + > 100% (range - 63.0% to + > 100%), p = 0.010. CONCLUSIONS: Our study suggests that patients undergoing LITT for RN have longer overall survival and better long-term lesional volume reduction than those treated with bevacizumab. However, it remains unclear whether our findings are due only to a difference in efficacy of the treatments or the implications of selection bias.

Detection of immune responses after immunotherapy in glioblastoma using PET and MRI.

Contrast-enhanced MRI is typically used to follow treatment response and progression in patients with glioblastoma (GBM). However, differentiating tumor progression from pseudoprogression remains a clinical dilemma largely unmitigated by current advances in imaging techniques. Noninvasive imaging techniques capable of distinguishing these two conditions could play an important role in the clinical management of patients with GBM and other brain malignancies. We hypothesized that PET probes for deoxycytidine kinase (dCK) could be used to differentiate immune inflammatory responses from other sources of contrast-enhancement on MRI. Orthotopic malignant gliomas were established in syngeneic immunocompetent mice and then treated with dendritic cell (DC) vaccination and/or PD-1 mAb blockade. Mice were then imaged with [18F]-FAC PET/CT and MRI with i.v. contrast. The ratio of contrast enhancement on MRI to normalized PET probe uptake, which we term the immunotherapeutic response index, delineated specific regions of immune inflammatory activity. On postmortem examination, FACS-based enumeration of intracranial tumor-infiltrating lymphocytes directly correlated with quantitative [18F]-FAC PET probe uptake. Three patients with GBM undergoing treatment with tumor lysate-pulsed DC vaccination and PD-1 mAb blockade were also imaged before and after therapy using MRI and a clinical PET probe for dCK. Unlike in mice, [18F]-FAC is rapidly catabolized in humans; thus, we used another dCK PET probe, [18F]-clofarabine ([18F]-CFA), that may be more clinically relevant. Enhanced [18F]-CFA PET probe accumulation was identified in tumor and secondary lymphoid organs after immunotherapy. Our findings identify a noninvasive modality capable of imaging the host antitumor immune response against intracranial tumors.

Immunosuppressive mechanisms for stem cell transplant survival in spinal cord injury.

Spinal cord injury (SCI) has been associated with a dismal prognosis-recovery is not expected, and the most standard interventions have been temporizing measures that do little to mitigate the extent of damage. While advances in surgical and medical techniques have certainly improved this outlook, limitations in functional recovery continue to impede clinically significant improvements. These limitations are dependent on evolving immunological mechanisms that shape the cellular environment at the site of SCI. In this review, we examine these mechanisms, identify relevant cellular components, and discuss emerging treatments in stem cell grafts and adjuvant immunosuppressants that target these pathways. As the field advances, we expect that stem cell grafts and these adjuvant treatments will significantly shift therapeutic approaches to acute SCI with the potential for more promising outcomes.

Epithelial membrane protein-2 (EMP2) promotes angiogenesis in glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor and is associated with an extremely poor clinical prognosis. One pathologic hallmark of GBM is excessive vascularization with abnormal blood vessels. Extensive investigation of anti-angiogenic therapy as a treatment for recurrent GBM has been performed. Bevacizumab, a monoclonal anti-vascular endothelial growth factor A (VEGF-A), suggests a progression-free survival benefit but no overall survival benefit. Developing novel anti-angiogenic therapies are urgently needed in controlling GBM growth. In this study, we demonstrate tumor expression of epithelial membrane protein-2 (EMP2) promotes angiogenesis both in vitro and in vivo using cell lines from human GBM. Mechanistically, this pro-angiogenic effect of EMP2 was partially through upregulating tumor VEGF-A levels. A potential therapeutic effect of a systemic administration of anti-EMP2 IgG1 on intracranial xenografts was observed resulting in both significant reduction of tumor load and decreased tumor vasculature. These results suggest the potential for anti-EMP2 IgG1 as a promising novel anti-angiogenic therapy for GBM. Further investigation is needed to fully understand the molecular mechanisms how EMP2 modulates GBM pathogenesis and progression and to further characterize anti-EMP2 therapy in GBM.

Dendritic cell immunotherapy for brain tumors.

Glioblastomas are characterized by immunosuppression, rapid proliferation, angiogenesis, and invasion into the surrounding brain parenchyma. Limitations in current therapeutic approaches have spurred the development of personalized, patient-specific treatments. Among these, active immunotherapy has emerged as a viable option for glioma treatment. The ability to generate an immune response utilizing patient-derived dendritic cells (DCs) (professional antigen-presenting cells) is especially attractive. This approach to glioma treatment allows for the immunologic targeting and destruction of malignant cells. Data acquired in multiple pre-clinical models and clinical trials have shown significant responses and prolonged survival. Here we provide an overview of the current status of DC vaccination for the treatment of gliomas.

Angiographic evidence of an inadvertent cannulation of the marginal sinus following central line migration: illustrative case.

BACKGROUND: Central venous catheters (CVCs) play an indispensable role in clinical practice. Catheter malposition and tip migration can lead to severe complications. The authors present a case illustrating the endovascular management of inadvertent marginal sinus cannulation after an internal jugular vein (IJV) catheter tip migration. OBSERVATIONS: A triple-lumen CVC was inserted without complications into the right IJV of a patient undergoing a repeat sternotomy for aortic valve replacement. Two weeks postinsertion, it was discovered that the tip had migrated superiorly, terminating below the torcula in the posterior fossa. In the interventional suite, a three-dimensional venogram confirmed the inadvertent marginal sinus cannulation. The catheter was carefully retracted to the sigmoid sinus to preserve the option of catheter exchange if embolization became necessary. After a subsequent venogram, which displayed an absence of contrast extravasation, the entire catheter was safely removed. The patient tolerated the procedure well. LESSONS: Clinicians must be vigilant of catheter tip migration and malposition risks. Relying solely on postinsertion radiographs is insufficient. Once identified, prompt management of the malpositioned catheter is paramount in reducing morbidity and mortality and improving patient outcomes. Removing a malpositioned catheter constitutes a critical step, best performed by a specialized team under angiographic visualization.

Improvement in cranial nerve palsies following treatment of intracranial aneurysms with flow diverters: Institutional outcomes, systematic review and study-level meta-analysis.

BACKGROUND: Cranial nerve (CN) palsies are rare presenting symptoms of intracranial aneurysms. Our objectives were to report our institutional outcomes and study-level meta-analysis summarizing rates of improvement and identifying factors associated with recovery from CN symptoms after flow diversion. METHODS: We conducted a retrospective review of our institutional database for patients with intracranial aneurysms presenting with CN palsies who underwent treatment with flow diversion between 2015 and 2023. Systematic review of the literature was performed using Medline, EMBASE, Cochrane, as well as manual citation searches. Random effects meta-analysis was used. RESULTS: Thirteen of 136 studies were included in the meta-analysis and were combined with our institutional data. The pooled rate of improvement in any CN palsies following flow diversion was 71 % (95 %CI, 60 %-82 %, n=322). Patients presenting with CN II deficits were less likely to improve following treatment compared to other CN deficits (pooled OR [pOR] 0.32, 95 %CI, 0.16-0.63, n=224). The pooled rate of clinical improvement was 53 % in CNII deficits (95 %CI, 42 %-65 %, n=80) and 80 % in other CN deficits (95 %CI, 71 %-88 %, n=106). An increased rate of improvement was associated with acute intervention (pOR 9.12, 95 % CI, 2.26-36.73, n = 71) and radiographic aneurysm occlusion (pOR 5.29, 95 %CI, 1.66-16.90, n=118). CONCLUSIONS: Flow diversion improves CN palsy outcomes in patients with symptomatic intracranial aneurysms. The lower rate of improvement in visual acuity compared to other CN deficits may point to a different mechanism of injury or potential recoverability in these patients.

Hospital Frailty Risk Score Predicts Adverse Events and Readmission Following a Ventriculoperitoneal Shunt Surgery for Normal Pressure Hydrocephalus.

OBJECTIVE: The aim of this study was to evaluate the impact of a Hospital Frailty Risk Score (HFRS) on unplanned readmission and health care resource utilization in normal pressure hydrocephalus (NPH) patients undergoing a ventriculoperitoneal (VP) shunt surgery. METHODS: A retrospective cohort study was performed using the 2016-2019 Nationwide Readmission Database. All NPH patients (≥60 years) undergoing a VP shunt surgery were identified using ICD-10-CM diagnostic and procedural codes. Patients were dichotomized into 2 cohorts as follows: Low HFRS (<5) and Intermediate-High HFRS (≥5). A multivariate logistic regression analysis was then used to identify independent predictors of adverse event (AE) and 30- and 90-day readmission. RESULTS: Of 13,262 patients, 4386 (33.1%) had an Intermediate-High HFRS score. A greater proportion of the Intermediate-High HFRS cohort experienced at least one AE (1.9 vs. 22.1, P < 0.001). The Intermediate-High HFRS cohort also had a longer length of stay (2.3 ± 2.4 days vs. 7.0 ± 7.7 days, P < 0.001), higher non-routine discharge rate (19.9% vs. 39.9%, P < 0.001), and greater admission cost ($14,634 ± 5703 vs. $21,749 ± 15,234, P < 0.001). The Intermediate-High HFRS cohort had higher rates of 30- (7.6% vs. 11.0%, P < 0.001) and 90-day (6.8% vs. 8.3%, P < 0.001) readmissions. On a multivariate regression analysis, Intermediate-High HFRS compared to Low HFRS was an independent predictor of any AE (odds ratio, 16.6; 95% confidence interval, [12.9-21.5]; P < 0.001) and 30-day readmission (odds ratio, 1.4; 95% confidence interval, [1.2-1.7]; P < 0.001). CONCLUSIONS: Our study suggests that frailty, as defined by HFRS, is associated with increased resource utilization in NPH patients undergoing VP shunt surgery. Furthermore, HFRS was an independent predictor of adverse events and 30-day hospital readmission.

Biallelic inactivation of PBRM1 as a molecular driver in a rare pineoblastoma case: illustrative case.

BACKGROUND: Pineoblastomas are a rare and aggressive pediatric neuroectodermal tumor subtype. Because of their rarity, pineoblastomas are still poorly understood, and there is little research delineating their molecular development and underlying genetic phenotype. Recent multiomic studies in pineoblastomas and pineal parenchymal tumors identified four clinically and biologically relevant consensus groups driven by signaling/processing pathways; however, molecular level alterations leading to these pathway changes are yet to be discovered, hence the importance of individually profiling every case of this rare tumor type. OBSERVATIONS: The authors present the comprehensive somatic genomic profiling of a patient with pineoblastoma presenting with the loss of protein polybromo-1 (PBRM1) as a candidate genomic driver. Loss of PBRM1, a tumor suppressor, has been reported as a driver event in various cancer types, including renal cell carcinoma, bladder carcinoma, and meningiomas with papillary features. LESSONS: This is the first report presenting biallelic loss of PBRM1 as a candidate molecular driver in relation to pineoblastoma.

Stereotactic radiosurgery and local control of brain metastases from triple-negative breast cancer.

OBJECTIVE: Stereotactic radiosurgery (SRS) is an effective treatment for intracranial metastatic disease, but its role in triple-negative breast cancer requires further study. Herein, the authors report overall survival (OS) and local tumor control in a multiinstitutional cohort with triple-negative breast cancer metastases treated with SRS. METHODS: Patients treated from 2010 to 2019 at 9 institutions were included in this retrospective study if they had biopsy-proven triple-negative breast cancer with intracranial metastatic lesions treated with SRS. Patients were excluded if they had undergone prior SRS, whole-brain radiation therapy, or resection of the metastatic lesions. A retrospective chart review was conducted to determine OS, local control, and treatment efficacy. RESULTS: Sixty-eight patients with 315 treated lesions were assessed. Patients had a median Karnofsky Performance Status of 80 (IQR 70-90) and age of 57 years (IQR 48-67 years). Most treated patients had 5 or fewer intracranial lesions, with 34% of patients having a single lesion. Treated lesions were small, having a median volume owf 0.11 cm3 (IQR 0.03-0.60 cm3). Patients were treated with a median margin dose of 18 Gy (IQR 18-20 Gy) to the median 71% isodose line (IQR 50%-84%). Overall, patients had a 1-year OS of 43% and 2-year OS of 20%. Most patients (88%) were followed until death, by which time local tumor progression had occurred in only 7% of cases. Furthermore, 76% of the lesions demonstrated regression. Tumor volume was correlated with local tumor progression (p = 0.012). SRS was very well tolerated, and only 3 patients (5%) developed symptomatic radiation necrosis. CONCLUSIONS: SRS is a safe and efficacious treatment for well-selected patients with triple-negative breast cancer, especially for those with a favorable performance status and small- to moderate-volume metastatic lesions.

Portable, bedside, low-field magnetic resonance imaging for evaluation of intracerebral hemorrhage.

Radiological examination of the brain is a critical determinant of stroke care pathways. Accessible neuroimaging is essential to detect the presence of intracerebral hemorrhage (ICH). Conventional magnetic resonance imaging (MRI) operates at high magnetic field strength (1.5-3 T), which requires an access-controlled environment, rendering MRI often inaccessible. We demonstrate the use of a low-field MRI (0.064 T) for ICH evaluation. Patients were imaged using conventional neuroimaging (non-contrast computerized tomography (CT) or 1.5/3 T MRI) and portable MRI (pMRI) at Yale New Haven Hospital from July 2018 to November 2020. Two board-certified neuroradiologists evaluated a total of 144 pMRI examinations (56 ICH, 48 acute ischemic stroke, 40 healthy controls) and one ICH imaging core lab researcher reviewed the cases of disagreement. Raters correctly detected ICH in 45 of 56 cases (80.4% sensitivity, 95%CI: [0.68-0.90]). Blood-negative cases were correctly identified in 85 of 88 cases (96.6% specificity, 95%CI: [0.90-0.99]). Manually segmented hematoma volumes and ABC/2 estimated volumes on pMRI correlate with conventional imaging volumes (ICC = 0.955, p = 1.69e-30 and ICC = 0.875, p = 1.66e-8, respectively). Hematoma volumes measured on pMRI correlate with NIH stroke scale (NIHSS) and clinical outcome (mRS) at discharge for manual and ABC/2 volumes. Low-field pMRI may be useful in bringing advanced MRI technology to resource-limited settings.

Cell-Based Immunotherapy of Gliomas.

Current cell-based immunotherapeutic strategies attempt to produce and maintain an immune response against glioma cells by artificially stimulating the immune system using passive and/or active approaches. Cellular immunotherapy is taken to mean the administration of live immune cells that either have immune effector capabilities themselves (passive immunotherapy) or engender a downstream antitumor response (active immunotherapy). Passive cellular immunotherapy most often takes the form of the adoptive transfer of a range of cell types, whereby antitumor immune cells from a patient (or allogeneic donor) are created, activated, and/or expanded ex vivo and subsequently administered back to the patient to directly attack the neoplasm. Active cellular immunotherapy approaches for the treatment of malignant gliomas have most often taken the form of dendritic cell (DC)-based vaccines.

Immunosuppressive tumor-infiltrating myeloid cells mediate adaptive immune resistance via a PD-1/PD-L1 mechanism in glioblastoma.

Background: Adaptive immune resistance in the tumor microenvironment appears to attenuate the immunotherapeutic targeting of glioblastoma (GBM). In this study, we identified a tumor-infiltrating myeloid cell (TIM) population that expands in response to dendritic cell (DC) vaccine treatment. The aim of this study was to understand how this programmed death ligand 1 (PD-L1)-expressing population restricts activation and tumor-cytolytic function of vaccine-induced tumor-infiltrating lymphocytes (TILs). Methods: To test this hypothesis in our in vivo preclinical model, we treated mice bearing intracranial gliomas with DC vaccination ± murine anti-PD-1 monoclonal antibody (mAb) blockade or a colony stimulating factor 1 receptor inhibitor (CSF-1Ri) (PLX3397) and measured overall survival. We then harvested and characterized the PD-L1+ TIM population and its role in TIL activation and tumor cytolysis in vitro. Results: Our data indicated that the majority of PD-L1 expression in the GBM environment is contributed by TIMs rather than by tumor cells themselves. While PD-1 blockade partially reversed the TIL dysfunction, targeting TIMs directly with CSF-1Ri altered TIM expression of key chemotactic factors associated with promoting increased TIL infiltration after vaccination. Neither PD-1 mAb nor CSF-1Ri had a demonstrable therapeutic benefit alone, but when combined with DC vaccination, a significant survival benefit was observed. When the tripartite regimen was given (DC vaccine, PD-1 mAb, PLX3397), long-term survival was noted together with an increase in the number of TILs and TIL activation. Conclusion: Together, these studies elucidate the role that TIMs play in mediating adaptive immune resistance in the GBM microenvironment and provide evidence that they can be manipulated pharmacologically with agents that are clinically available. Development of immune resistance in response to active vaccination in GBM can be reversed with dual administration of CSF-1Ri and PD-1 mAb.

PD-1 blockade enhances the vaccination-induced immune response in glioma.

DC vaccination with autologous tumor lysate has demonstrated promising results for the treatment of glioblastoma (GBM) in preclinical and clinical studies. While the vaccine appears capable of inducing T cell infiltration into tumors, the effectiveness of active vaccination in progressively growing tumors is less profound. In parallel, a number of studies have identified negative costimulatory pathways, such as programmed death 1/programmed death ligand 1 (PD-1/PD-L1), as relevant mediators of the intratumoral immune responses. Clinical responses to PD-1 pathway inhibition, however, have also been varied. To evaluate the relevance to established glioma, the effects of PD-1 blockade following DC vaccination were tested in intracranial (i.c.) glioma tumor- bearing mice. Treatment with both DC vaccination and PD-1 mAb blockade resulted in long-term survival, while neither agent alone induced a survival benefit in animals with larger, established tumors. This survival benefit was completely dependent on CD8+ T cells. Additionally, DC vaccine plus PD-1 mAb blockade resulted in the upregulation of integrin homing and immunologic memory markers on tumor-infiltrating lymphocytes (TILs). In clinical samples, DC vaccination in GBM patients was associated with upregulation of PD-1 expression in vivo, while ex vivo blockade of PD-1 on freshly isolated TILs dramatically enhanced autologous tumor cell cytolysis. These findings strongly suggest that the PD-1/PD-L1 pathway plays an important role in the adaptive immune resistance of established GBM in response to antitumor active vaccination and provide us with a rationale for the clinical translation of this combination therapy.

Efficacy of systemic adoptive transfer immunotherapy targeting NY-ESO-1 for glioblastoma.

BACKGROUND: Immunotherapy is an ideal treatment modality to specifically target the diffusely infiltrative tumor cells of malignant gliomas while sparing the normal brain parenchyma. However, progress in the development of these therapies for glioblastoma has been slow due to the lack of immunogenic antigen targets that are expressed uniformly and selectively by gliomas. METHODS: We utilized human glioblastoma cell cultures to induce expression of New York-esophageal squamous cell carcinoma (NY-ESO-1) following in vitro treatment with the demethylating agent decitabine. We then investigated the phenotype of lymphocytes specific for NY-ESO-1 using flow cytometry analysis and cytotoxicity against cells treated with decitabine using the xCelligence real-time cytotoxicity assay. Finally, we examined the in vivo application of this immune therapy using an intracranially implanted xenograft model for in situ T cell trafficking, survival, and tissue studies. RESULTS: Our studies showed that treatment of intracranial glioma-bearing mice with decitabine reliably and consistently induced the expression of an immunogenic tumor-rejection antigen, NY-ESO-1, specifically in glioma cells and not in normal brain tissue. The upregulation of NY-ESO-1 by intracranial gliomas was associated with the migration of adoptively transferred NY-ESO-1-specific lymphocytes along white matter tracts to these tumors in the brain. Similarly, NY-ESO-1-specific adoptive T cell therapy demonstrated antitumor activity after decitabine treatment and conferred a highly significant survival benefit to mice bearing established intracranial human glioma xenografts. Transfer of NY-ESO-1-specific T cells systemically was superior to intracranial administration and resulted in significantly extended and long-term survival of animals. CONCLUSION: These results reveal an innovative, clinically feasible strategy for the treatment of glioblastoma.

TCR Sequencing Can Identify and Track Glioma-Infiltrating T Cells after DC Vaccination.

Although immunotherapeutic strategies are emerging as adjunctive treatments for cancer, sensitive methods of monitoring the immune response after treatment remain to be established. We used a novel next-generation sequencing approach to determine whether quantitative assessments of tumor-infiltrating lymphocyte (TIL) content and the degree of overlap of T-cell receptor (TCR) sequences in brain tumors and peripheral blood were predictors of immune response and overall survival in glioblastoma patients treated with autologous tumor lysate-pulsed dendritic cell immunotherapy. A statistically significant correlation was found between a higher estimated TIL content and increased time to progression and overall survival. In addition, we were able to assess the proportion of shared TCR sequences between tumor and peripheral blood at time points before and after therapy, and found the level of TCR overlap to correlate with survival outcomes. Higher degrees of overlap, or the development of an increased overlap following immunotherapy, was correlated with improved clinical outcome, and may provide insights into the successful, antigen-specific immune response. Cancer Immunol Res; 4(5); 412-8. ©2016 AACR.

pH-weighted molecular imaging of gliomas using amine chemical exchange saturation transfer MRI.

BACKGROUND: Interstitial tissue acidosis resulting from abnormal perfusion and metabolism is a hallmark of cancer. The current study demonstrates that chemical exchange saturation transfer (CEST) MRI can be used as a noninvasive pH-weighted molecular imaging technique by targeting the chemical exchange between amine protons and protons in extracellular bulk water. METHODS: First, the sensitivity of amine CEST was validated in phantoms under a variety of conditions, including different magnetic field strengths, amino acid concentrations, and pH values. Amine CEST was compared with histology in both a preclinical GL261 intracranial glioma model at 7T and human patients at 3T. The association between physiologic and pH-weighted MRI was explored, along with the ability to predict time to progression to radiochemotherapy in 20 glioblastoma patients. RESULTS: z-Spectral asymmetry increased at 3 ppm (amine range) on CEST MRI with decreasing pH within the range observed in tumors for both 3T and 7T scanners. Lesions with acidic signatures showed active tumor and pseudopalisading tumor on histology and showed elevated FDOPA PET uptake, lactate on MR spectroscopy, and perfusion abnormalities. Patients with acidic lesions after surgery or stable/growing acidic lesions had a shorter time to progression following radiochemotherapy compared with patients with lesions demonstrating relatively low acidity (P < .001). CONCLUSION: Results suggest pH-weighted MRI may provide new insight into brain tumor physiology beyond traditional imaging technologies.