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The central nervous system (CNS) antigen-presenting cell (APC) that primes antitumor CD8+ T-cell responses remains undefined. Elsewhere in the body, the conventional dendritic cell 1 (cDC1) performs this role. However, steady-state brain parenchyma cDC1 are extremely rare; cDCs localize to the choroid plexus and dura. Thus, whether the cDC1 play a function in presenting antigen derived from parenchymal sources in the tumor setting remains unknown. Using preclinical glioblastoma (GBM) models and cDC1-deficient mice, we explored the presently unknown role of cDC1 in CNS antitumor immunity. We determined that, in addition to infiltrating the brain tumor parenchyma itself, cDC1 prime neoantigen-specific CD8+ T cells against brain tumors and mediate checkpoint blockade-induced survival benefit. We observed that cDC, including cDC1, isolated from the tumor, the dura, and the CNS-draining cervical lymph nodes harbored a traceable fluorescent tumor antigen. In patient samples, we observed several APC subsets (including the CD141+ cDC1 equivalent) infiltrating glioblastomas, meningiomas, and dura. In these same APC subsets, we identified a tumor-specific fluorescent metabolite of 5-aminolevulinic acid, which fluorescently labeled tumor cells during fluorescence-guided GBM resection. Together, these data elucidate the specialized behavior of cDC1 and suggest that cDC1 play a significant role in CNS antitumor immunity.

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The central nervous system (CNS) antigen-presenting cell (APC) that primes antitumor CD8+ T-cell responses remains undefined. Elsewhere in the body, the conventional dendritic cell 1 (cDC1) performs this role. However, steady-state brain parenchyma cDC1 are extremely rare; cDCs localize to the choroid plexus and dura. Thus, whether the cDC1 play a function in presenting antigen derived from parenchymal sources in the tumor setting remains unknown. Using preclinical glioblastoma (GBM) models and cDC1-deficient mice, we explored the presently unknown role of cDC1 in CNS antitumor immunity. We determined that, in addition to infiltrating the brain tumor parenchyma itself, cDC1 prime neoantigen-specific CD8+ T cells against brain tumors and mediate checkpoint blockade-induced survival benefit. We observed that cDC, including cDC1, isolated from the tumor, the dura, and the CNS-draining cervical lymph nodes harbored a traceable fluorescent tumor antigen. In patient samples, we observed several APC subsets (including the CD141+ cDC1 equivalent) infiltrating glioblastomas, meningiomas, and dura. In these same APC subsets, we identified a tumor-specific fluorescent metabolite of 5-aminolevulinic acid, which fluorescently labeled tumor cells during fluorescence-guided GBM resection. Together, these data elucidate the specialized behavior of cDC1 and suggest that cDC1 play a significant role in CNS antitumor immunity.

Sonobiopsy is an emerging technology that combines focused ultrasound (FUS) with microbubbles to enrich circulating brain disease-specific biomarkers for noninvasive molecular diagnosis of brain diseases. Here, we report the first-in-human prospective trial of sonobiopsy in glioblastoma patients to evaluate its feasibility and safety in enriching circulating tumor biomarkers. A nimble FUS device integrated with a clinical neuronavigation system was used to perform sonobiopsy following an established clinical workflow for neuronavigation. Analysis of blood samples collected before and after FUS sonication showed enhanced plasma circulating tumor biomarker levels. Histological analysis of surgically resected tumors confirmed the safety of the procedure. Transcriptome analysis of sonicated and unsonicated tumor tissues found that FUS sonication modulated cell physical structure-related genes but evoked minimal inflammatory response. These feasibility and safety data support the continued investigation of sonobiopsy for noninvasive molecular diagnosis of brain diseases.

Since the late 19th century, the immune system has increasingly garnered interest as a novel avenue for cancer therapy, particularly given scientific breakthroughs in recent decades delineating the fundamental role of the immune system in tumorigenesis. The immunoediting hypothesis has articulated this role, describing three phases of the tumor-immune system interaction: Elimination, Equilibrium, and Escape wherein tumors progress from active immunologic surveillance and destruction through dynamic immunologic stasis to unfettered growth. The primary goals of immunotherapy are to restrict and revert progression through these phases, thereby improving the immune system's ability to control tumor growth. In this review, we detail the development and foundation of the cancer immunoediting hypothesis and apply this hypothesis to the dynamic immunotherapy field that includes checkpoint blockade, vaccine therapy, and adoptive cell transfer.

Though surgical biopsies provide direct access to tissue for genomic characterization of brain cancer, they are invasive and pose significant clinical risks. Brain cancer management via blood-based liquid biopsies is a minimally invasive alternative; however, the blood-brain barrier (BBB) restricts the release of brain tumor-derived molecular biomarkers necessary for sensitive diagnosis. Methods: A mouse glioblastoma multiforme (GBM) model was used to demonstrate the capability of focused ultrasound (FUS)-enabled liquid biopsy (sonobiopsy) to improve the diagnostic sensitivity of brain tumor-specific genetic mutations compared with conventional blood-based liquid biopsy. Furthermore, a pig GBM model was developed to characterize the translational implications of sonobiopsy in humans. Magnetic resonance imaging (MRI)-guided FUS sonication was performed in mice and pigs to locally enhance the BBB permeability of the GBM tumor. Contrast-enhanced T1-weighted MR images were acquired to evaluate the BBB permeability change. Blood was collected immediately after FUS sonication. Droplet digital PCR was used to quantify the levels of brain tumor-specific genetic mutations in the circulating tumor DNA (ctDNA). Histological staining was performed to evaluate the potential for off-target tissue damage by sonobiopsy. Results: Sonobiopsy improved the detection sensitivity of EGFRvIII from 7.14% to 64.71% and TERT C228T from 14.29% to 45.83% in the mouse GBM model. It also improved the diagnostic sensitivity of EGFRvIII from 28.57% to 100% and TERT C228T from 42.86% to 71.43% in the porcine GBM model. Conclusion: Sonobiopsy disrupts the BBB at the spatially-targeted brain location, releases tumor-derived DNA into the blood circulation, and enables timely collection of ctDNA. Converging evidence from both mouse and pig GBM models strongly supports the clinical translation of sonobiopsy for the minimally invasive, spatiotemporally-controlled, and sensitive molecular characterization of brain cancer.

Many groups have reported lymphatic and glymphatic structures in animal and human brains, but tracer injection into the human brain to demonstrate real-time lymphatic drainage and mapping has not been described. We enrolled patients undergoing standard-of-care resection or stereotactic biopsy for suspected intracranial tumors. Patients received peritumoral injections of 99mTc-tilmanocept followed by planar or tomographic imaging. Fourteen patients with suspected brain tumors were enrolled. One was excluded from analysis because of tracer leakage during injection. There was no drainage of 99mTc-tilmanocept to regional lymph nodes in any of the patients. On average, after correcting for radioactive decay, 70.7% (95% CI: 59.9%, 81.6%) of the tracer in the injection site and 78.1% (95% CI: 71.1%, 85.1%) in the whole-head on the day of surgery remained the morning after, with variable radioactivity in the subarachnoid space. The retained fraction was much greater than expected based on the clearance rate from non-brain injection sites. In this pilot study, the lymphatic tracer 99mTc-tilmanocept was injected into the brain parenchyma, and there was no drainage outside the brain to the cervical lymph nodes. Our work demonstrates an inefficiency of drainage from peritumoral brain parenchyma and highlights a therapeutic opportunity to improve immunosurveillance of the brain.

Glioblastoma is a primary brain tumor with a dismal prognosis. CD4 T cell responses to neoantigen vaccines or checkpoint blockade immunotherapy impact the tumor microenvironment. However, the function of CD4 T cells in glioblastoma remains understudied. Here we further characterize the role of CD4 T cells in antitumor immunity against the GL261 orthotopic model of glioblastoma. We studied the memory response generated during high-dose PD-L1 blockade mediated clearance of intracranial tumors. Mice that previously rejected GL261 retained protection against intracranial rechallenge after depletion of CD4 or CD8 T cells, but not both. Thus, these memory CD4 T cells are sufficient but not necessary for protection. Interestingly, in mice with a memory response generated during clearance of extracranial GL261, depletion of CD4 T cells abrogates protection against intracranial rechallenge, but depletion of CD8 T cells alone does not affect protection. Therefore, memory CD4 T cells generated with extracranial antigen challenge are necessary and sufficient for protection against intracranial rechallenge. In an analogous setting, we vaccinated mice against MHC class I neoantigens with concurrent checkpoint blockade immunotherapy to generate memory responses. Similar to the challenge-rechallenge model, mice challenged with GL261 and depleted of CD4 T cells lost protection from neoantigen vaccination and PD-L1 blockade. We then modified GL261 to express the C-terminal end of ovalbumin (GL261-OVAII), which contains the MHC class II immunodominant antigen (OVA323-339) but not the class I antigen (OVA257-264). Mice challenged intracranially with GL261-OVAII have a minimal survival benefit from PD-L1 blockade therapy. However, vaccination against OVA323-339 greatly enhances the protection from PD-L1 blockade. We determined by ELISPOT that CD4 T cells do not directly recognize GL261. Our data show the importance of the CD4 T cell subset in glioblastoma and the importance of targeting class II neoantigens to generate strong antitumor immunity.

BackgroundAdoptive cellular therapies with chimeric antigen receptor T cells have revolutionized the treatment of some malignancies but have shown limited efficacy in solid tumors such as glioblastoma and face a scarcity of safe therapeutic targets. As an alternative, T cell receptor (TCR)–engineered cellular therapy against tumor-specific neoantigens has generated significant excitement, but there exist no preclinical systems to rigorously model this approach in glioblastoma.MethodsWe employed single-cell PCR to isolate a TCR specific for the Imp3D81Nneoantigen (mImp3) previously identified within the murine glioblastoma model GL261. This TCR was used to generate the Mutant Imp3-Specific TCR TransgenIC (MISTIC) mouse in which all CD8 T cells are specific for mImp3. The therapeutic efficacy of neoantigen-specific T cells was assessed through a model of cellular therapy consisting of the transfer of activated MISTIC T cells and interleukin 2 into lymphodepleted tumor-bearing mice. We employed flow cytometry, single-cell RNA sequencing, and whole-exome and RNA sequencing to examine the factors underlying treatment response.ResultsWe isolated and characterized the 3×1.1C TCR that displayed a high affinity for mImp3 but no wild-type cross-reactivity. To provide a source of mImp3-specific T cells, we generated the MISTIC mouse. In a model of adoptive cellular therapy, the infusion of activated MISTIC T cells resulted in rapid intratumoral infiltration and profound antitumor effects with long-term cures in a majority of GL261-bearing mice. The subset of mice that did not respond to the adoptive cell therapy showed evidence of retained neoantigen expression but intratumoral MISTIC T cell dysfunction. The efficacy of MISTIC T cell therapy was lost in mice bearing a tumor with heterogeneous mImp3 expression, showcasing the barriers to targeted therapy in polyclonal human tumors.ConclusionsWe generated and characterized the first TCR transgenic against an endogenous neoantigen within a preclinical glioma model and demonstrated the therapeutic potential of adoptively transferred neoantigen-specific T cells. The MISTIC mouse provides a powerful novel platform for basic and translational studies of antitumor T-cell responses in glioblastoma.

BackgroundGlioblastoma is a fatal disease despite aggressive multimodal therapy. PD-1 blockade, a therapy that reinvigorates hypofunctional exhausted CD8 T cells (Tex) in many malignancies, has not shown efficacy in glioblastoma. Loss of CD4 T cells can lead to an exhausted CD8 T-cell phenotype, and terminally exhausted CD8 T cells (Texterm) do not respond to PD-1 blockade. GL261 and CT2A are complementary orthotopic models of glioblastoma. GL261 has a functional CD4 T-cell compartment and is responsive to PD-1 blockade; notably, CD4 depletion abrogates this survival benefit. CT2A is composed of dysfunctional CD4 T cells and is PD-1 blockade unresponsive. We leverage these models to understand the impact of CD4 T cells on CD8 T-cell exhaustion and PD-1 blockade sensitivity in glioblastoma.MethodsSingle-cell RNA sequencing was performed on flow sorted tumor-infiltrating lymphocytes from female C57/BL6 mice implanted with each model, with and without PD-1 blockade therapy. CD8+and CD4+T cells were identified and separately analyzed. Survival analyses were performed comparing PD-1 blockade therapy, CD40 agonist or combinatorial therapy.ResultsThe CD8 T-cell compartment of the models is composed of heterogenous CD8 Texsubsets, including progenitor exhausted CD8 T cells (Texprog), intermediate Tex, proliferating Tex, and Texterm. GL261 is enriched with the PD-1 responsive Texprogsubset relative to the CT2A and CD4-depleted GL261 models, which are composed predominantly of the PD-1 blockade refractory Textermsubset. Analysis of the CD4 T-cell compartments revealed that the CT2A microenvironment is enriched with a suppressive Tregsubset and an effector CD4 T-cell subset that expresses an inhibitory interferon-stimulated (Isc) signature. Finally, we demonstrate that addition of CD40 agonist to PD-1 blockade therapy improves survival in CT2A tumor-bearing mice.ConclusionsHere, we describe that dysfunctional CD4 T cells are associated with terminal CD8 T-cell exhaustion, suggesting CD4 T cells impact PD-1 blockade efficacy by controlling the severity of exhaustion. Given that CD4 lymphopenia is frequently observed in patients with glioblastoma, this may represent a basis for resistance to PD-1 blockade. We demonstrate that CD40 agonism may circumvent a dysfunctional CD4 compartment to improve PD-1 blockade responsiveness, supporting a novel synergistic immunotherapeutic approach.

The central nervous system (CNS) antigen presenting cell (APC) which primes anti-tumor CD8+ T cell responses remains undefined. Elsewhere, the conventional dendritic cell 1 (cDC1) performs this role. However, steady-state brain cDC1 are rare; cDC localize to choroid plexus and dura. Using preclinical glioblastoma models and cDC1-deficient mice, we explored the role of cDC1 in CNS anti-tumor immunity. We determined that cDC1 mediate checkpoint blockade-induced survival benefit and prime neoantigen-specific CD8+ T cells against brain tumors. We observed that cDC, including cDC1, isolated from the tumor, the dura, and the CNS-draining cervical lymph nodes harbored a traceable fluorescent tumor-antigen. In patient samples, we observed several APC subsets (including the CD141+ cDC1-equivalent) infiltrating glioblastomas, meningiomas, and dura. In these same subsets, we identified a tumor-specific fluorescent metabolite of 5- aminolevulinic acid, which labels tumor cells during fluorescence-guided glioblastoma resection. Together, these data elucidate the specialized behavior of cDC1 and suggest cDC1 play a significant role in CNS anti-tumor immunity.One Sentence SummaryCNS cDC1 engage in previously undefined behavior to establish immune responses against brain tumors.

INTRODUCTION Many groups have reported lymphatic and glymphatic structures in animal and human brains, but tracer injection into the human brain to demonstrate real-time lymphatic drainage and mapping has not been reported. Technetium (99mTc) tilmanocept is a radiopharmaceutical agent that binds CD206 and maps draining lymph nodes. We hypothesized that peritumoral 99mTc-tilmanocept injection into the brain parenchyma would map drainage to cervical lymph nodes. Here we show a paucity of tracer movement after injection due to a presumed inefficiency of glymphatic and lymphatic drainage. METHODS We enrolled 14 patients undergoing resection or stereotactic biopsy of suspected benign or malignant intracranial tumors. Patients received peritumoral injections of 99mTc-tilmanocept followed by planar or tomographic imaging. One patient was excluded from analysis because of tracer leakage during injection. RESULTS No patients showed drainage of 99mTc-tilmanocept to regional lymph nodes. On average, after correcting for radioactive decay, 70.1% (95% CI: 60.0%, 81.6%) of the tracer in the injection site and 78.1% (95% CI: 71.1%, 85.1%) in the whole-head on the day of surgery remained the morning after, with variable radioactivity in the subarachnoid space. The remaining fraction at the injection site was much larger than the expected fraction of 1.12% (95% CI: 1.07%, 1.17%) based on previously reported clearance rates from non-brain injections. We determined that this lack of drainage was not due to sequestration by a large population of CD206+ cells via immunohistochemistry of peritumoral tissue sections. Patients with benign or malignant tumors and a patient who underwent or minimally invasive stereotactic biopsy all showed no drainage. DISCUSSION In this pilot study, the lymphatic tracer 99mTc-tilmanocept was injected into the brain parenchyma, and there was an absence of drainage to the cervical lymph nodes. Our work demonstrates an inefficiency of drainage from the brain parenchyma and highlights an opportunity to improve brain immunosurveillance.

Background Recent investigations of the meninges have highlighted the importance of the dura layer in central nervous system immune surveillance beyond a purely structural role. However, our understanding of the meninges largely stems from the use of pre-clinical models rather than human samples. Methods Single-cell RNA sequencing of seven non-tumor-associated human dura samples and six primary meningioma tumor samples (4 matched and 2 non-matched) was performed. Cell type identities, gene expression profiles, and T cell receptor expression were analyzed. Copy number variant (CNV) analysis was performed to identify putative tumor cells and analyze intratumoral CNV heterogeneity. Immunohistochemistry and imaging mass cytometry was performed on selected samples to validate protein expression and reveal spatial localization of select protein markers. Results In this study, we use single-cell RNA sequencing to perform the first characterization of both non-tumor-associated human dura and primary meningioma samples. First, we reveal a complex immune microenvironment in human dura that is transcriptionally distinct from that of meningioma. In addition, we characterize a functionally diverse and heterogenous landscape of non-immune cells including endothelial cells and fibroblasts. Through imaging mass cytometry, we highlight the spatial relationship among immune cell types and vasculature in non-tumor-associated dura. Utilizing T cell receptor sequencing, we show significant TCR overlap between matched dura and meningioma samples. Finally, we report copy number variant heterogeneity within our meningioma samples. Conclusions Our comprehensive investigation of both the immune and non-immune cellular landscapes of human dura and meningioma at single-cell resolution builds upon previously published data in murine models and provides new insight into previously uncharacterized roles of human dura.

Recent investigation of the meninges, specifically the dura layer, has highlighted its importance in CNS immune surveillance beyond a purely structural role. However, most of our understanding of the meninges stems from the use of pre-clinical models rather than human samples. In this study, we use single cell RNA-sequencing to perform the first characterization of both non-tumor-associated human dura and meningioma samples. First, we reveal a complex immune microenvironment in human dura that is transcriptionally distinct from that of meningioma. In addition, through T cell receptor sequencing, we show significant TCR overlap between matched dura and meningioma samples. We also identify a functionally heterogeneous population of non-immune cell types and report copy-number variant heterogeneity within our meningioma samples. Our comprehensive investigation of both the immune and non-immune cell landscapes of human dura and meningioma at a single cell resolution provide new insight into previously uncharacterized roles of human dura.

Purpose: Chimeric antigen receptor (CAR) T cells have shown promise against solid tumors, but their efficacy has been limited, due in part, to immunosuppression by CD4+FoxP3+ regulatory T cells (Tregs). Although lymphodepletion is commonly used to deplete Tregs, these regimens are nonspecific, toxic, and provide only a narrow window before Tregs repopulate hosts. Importantly, CARs have also been shown to inadvertently potentiate Tregs by providing a source of IL2 for Treg consumption. We explored whether disruption of the IL2 axis would confer efficacy against solid tumors without the need for lymphodepletion. Experimental Design: We developed second- (CD28z) and third- (CD28-4-1BBz) generation CARs targeting EGFRvIII. To eliminate secretion of IL2, 2 amino acid substitutions were introduced in the PYAP Lck–binding motif of the CD28 domain (ΔCD28). We evaluated CARs against B16 melanomas expressing EGFRvIII. Results: CD28z CARs failed to engraft in vivo. Although 4-1BB addition improved expansion, CD28-4-1BBz CARs required lymphodepletion to treat solid tumors. CARs deficient in Lck signaling, however, significantly retarded tumor growth without a need for lymphodepletion and this was dependent on inclusion of 4-1BB. To evaluate CAR vulnerability to Tregs, we lymphodepleted mice and transferred CARs alone or with purified Tregs. Cotransfer with Tregs abrogated the efficacy of CD28-4-1BBz CARs, whereas the efficacy of ΔCD28-4-1BBz CARs remained unperturbed. Conclusions: In the absence of lymphodepletion, CARs targeting solid tumors are hindered by Treg immunosuppression and poor persistence. Here, CARs were modified to circumvent Treg suppression and to simultaneously improve in vivo engraftment. Modified CARs treated solid tumors without a need for lymphodepletion.

The Gamma Knife Center of St. Louis has established itself as a key facility offering stereotactic radiosurgery (SRS) for a variety of neuro-oncologic disorders. Since the Gamma Knife unit was first brought to Washington University in 1997, we have treated 5,696 patients. In this review, we discuss the effective role of Gamma Knife SRS in the treatment strategies for patients with neuro-oncologic disorders including brain metastases, meningiomas, pituitary adenomas, and acoustic neuromas. While there is active ongoing research evaluating the most effective treatment for patients with these disorders, it is clear that best management practices may be tailored for individual patients utilizing SRS either alone or in conjunction alternative treatment strategies including open neurosurgical procedures, laser thermos-ablative surgery, and even new medical oncological treatment strategies.

Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon’s exposure to ionizing radiation is not easily recognizable without a digital dosimeter—something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure. The senior surgeon wore a digital dosimeter during all minimally invasive spine fusion procedures performed over a 12-month period. Patient demographics, procedure information, and radiation exposure throughout the procedure were recorded. Fifty-five minimally invasive spine fusions utilizing 330 percutaneous screws were included. Average radiation dose was 0.46 Rad/screw to the patient. Average radiation exposure to the surgeon was 1.06 ± 0.71 μSv/screw, with a strong positive correlation (r = 0.77) to patient dose. The coefficient of determination (r2) was 0.5928, meaning almost two-thirds of the variability in radiation exposure to the surgeon is explained by radiation exposure to the patient. Intra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material

Hospital readmission after surgery results in a substantial economic burden, and several recent studies have investigated the impact of race and ethnicity on hospital readmission rates, with the goal to identify hospitals and patients with high readmission risk. This single-institution, retrospective cohort study assesses the impact of race, along with other risk factors, on 30-day readmission rates following spinal surgery. This study is a single-institution retrospective cohort study with accrual from January 1, 2008, to December 31, 2010. Inclusion criteria included adult patients who underwent anterior and/or posterior spinal surgery. The primary aim of this study was to assess the impact of patient race and other risk factors for postoperative hospital readmission within 30 days following spine surgery. A total of 1346 patients (654 male, 692 female) were included in the study. Overall, 159 patients (11.8%) were readmitted in the 30 days following their surgery. Multivariate logistic regression found significant risk factors for 30-day readmission, including Black race (OR: 2.20, C.I. 95% (1.04, 4.64)) and total length of stay greater than 7 days (OR: 4.73, C.I. 95% (1.72, 12.98)). Cervical surgery was associated with decreased odds of readmission (OR: 0.27, C.I. 95% (0.08, 0.91)). Our study demonstrates that race and length of hospital stay influence the incidence of 30-day readmission rates after spinal surgery. Studies such as ours will aid in identifying patients with postoperative readmission risk and help elucidate the underlying factors that may be contributing to disparities in readmission after surgery.

We investigated the effect of preoperative patient demographics and operative factors on mortality in the 30day postoperative period after spine surgery. Postoperative mortality from surgical interventions has significantly decreased with progressive improvement in surgical techniques and patient selection. Well-studied preoperative risk factors include age, obesity, emphysema, clotting disorders, renal failure, and cardiovascular disease. However, the prognostic implications of such risk factors after spine surgery specifically remain unknown. The medical records of all consecutive patients undergoing spine surgery from 2008-2010 at our institution were reviewed. Patient demographics, comorbidities, indication for operation, surgical details, postoperative complications, and mortalities were collected. The association between preoperative demographics or surgical details and postoperative mortality was assessed via logistic regression analysis. All 1344 consecutive patients (1153 elective, 191 emergency) met inclusion criteria for the study; 19 (1.4%) patients died in the 30days following surgery. Multivariable logistic regression found several predictive factors of mortality for all spine surgery patients: operation in the cervical area (odds ratio [OR]: 7.279, 95% confidence interval [CI]: 1.37-42.83, p=0.02), postoperative sepsis (OR: 5.75, 95% CI: 1.16-26.38, p=0.03), operation for neoplastic (OR: 7.68, 95% CI: 1.53-42.71, p=0.01) or traumatic (OR: 13.76, 95% CI: 2.40-88.68, p=0.03) etiology, and age as defined as a continuous variable (OR: 1.05, 95% CI: 1.01-1.10, p=0.03). This study demonstrates predictive factors to help identify and evaluate patients who are at higher risk for mortality from spinal surgery, and potentially devise methods to reduce this risk.

Immunotherapy for brain cancer has evolved dramatically over the past decade, owed in part to our improved understanding of how the immune system interacts with tumors residing within the central nervous system (CNS). Glioblastoma (GBM), the most common primary malignant brain tumor in adults, carries a poor prognosis (15 months) and only few advances have been made since the FDA's approval of temozolomide (TMZ) in 2005. Importantly, several immunotherapies have now entered patient trials based on promising preclinical data, and recent studies have shed light on how GBM employs a slew of immunosuppressive mechanisms that may be targeted for therapeutic gain. Altogether, accumulating evidence suggests immunotherapy may soon earn its keep as a mainstay of clinical management for GBM.Here, we review cancer vaccines, checkpoint inhibitors, adoptive T-cell immunotherapy, and oncolytic virotherapy.Checkpoint blockade induces antitumor activity by preventing negative regulation of T-cell activation. This platform, however, depends on an existing frequency of tumor-reactive T cells. GBM tumors are exceptionally equipped to prevent this, occupying low levels of antigen expression and elaborate mechanisms of immunosuppression. Therefore, checkpoint blockade may be most effective when used in combination with a DC vaccine or adoptively transferred tumor-specific T cells generated ex vivo. Both approaches have been shown to induce endogenous immune responses against tumor antigens, providing a rationale for use with checkpoint blockade where both primary and secondary responses may be potentiated.

STUDY DESIGN A retrospective review. OBJECTIVE The aim of the study was to perform a risk assessment of 30-day perioperative myocardial infarction (MI) for spine surgery patients. SUMMARY OF BACKGROUND DATA There is an increased emphasis to reduce complications and improve outcomes after spinal surgery. One of the more devastating perioperative complications of spinal surgery is MI. METHODS We evaluated all medical records of 1346 consecutive patients who underwent spinal surgery at a single institution from 2008 to 2010 for incidence of MI within 30 days of surgery and documented all demographic, preoperative, and operative variables. Associations between postoperative MI and individual risk factors were determined using logistic regression analysis. Patients were stratified into emergent and elective groups and a similar analysis was performed. RESULTS Overall, 22 patients (1.6%) had 30-day perioperative MI, 14 patients (1.2%) undergoing elective surgery, and 8 patients (4.2%) after emergent surgery (P = 0.047). Three (13.6%) patients experienced 30-day mortality and an additional 3 (13.6%) patients experienced mortality within 1 year. Multivariate logistic regression determined that age more than 65 years, atrial fibrillation, hypertension, prior MI, anticoagulant use, low albumin, length of stay more than 7 days, intraoperative transfusion, trauma etiology, baseline creatinine more than 1 mg/dL, and at least 2 levels of spinal fusion were predictive of postoperative MI. For patients undergoing emergent surgery, age more than 65 years was associated with an increased risk of postoperative MI. When stratified by elective surgery, we found that age more than 65, postoperative stay more than 7 days, intraoperative blood transfusion, baseline creatinine more than 1 mg/dL, and fusion of more than 1 level were associated with an increased risk of MI. CONCLUSION The present study demonstrates a low incidence of MI after elective surgery with a higher incidence after emergent spine surgery and identifies patient factors predictive of postoperative MI. LEVEL OF EVIDENCE 3.

Background Deep vein thrombosis (DVT) is a morbid postsurgical complication. Identifying the perioperative DVT risk profile will improve surgeons' ability to assess patients for surgical candidacy. In addition, these data will help to identify patients who would benefit from DVT chemoprophylaxis. Methods We evaluated all medical records for 1346 consecutive patients who underwent spinal surgery at Duke University for incidence of DVT within 30 days of surgery and documented all demographic, preoperative, operative, and postoperative variables. DVT treatment and long-term outcomes were also documented. Associations between postoperative DVT and individual risk factors in all patients were determined using adjusted logistic regression analysis. Patients were stratified into emergent and elective groups and a similar analysis was performed. Results Overall, 15 patients (1.1%) had a DVT in the 30 days after surgery, 7 patients (0.6%) after elective surgery and 8 patients (4.2%) after emergent surgery ( P = 0.03). Overall, multivariate logistic regression determined that previous DVT, postoperative urinary tract infection, and creatinine level >2.0 mg/dL were identified as positive predictors. When stratified by emergent surgery, we found packed red blood cell transfusion, surgical blood loss >2.0 L, and deep surgical site infection to be independently associated with increased risk of postoperative DVT. When stratified by elective surgery, we found that coronary artery disease and atrial fibrillation were associated with increased risk of DVT. No patients died in the 30-day perioperative period and 5 (33.3%) patients died within 1 year. Conclusions This study identifies patient factors predictive of postoperative DVT. Postoperative DVT prophylaxis may be warranted for patients undergoing emergent spine surgery because these patients have significantly higher risk of developing postoperative DVT.

Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) is an effective immunotherapy for B-cell malignancies but has failed in some solid tumors clinically. Intracerebral tumors may pose challenges that are even more significant. In order to devise a treatment strategy for patients with glioblastoma (GBM), we evaluated CARs as a monotherapy in a murine model of GBM. CARs exhibited poor expansion and survival in circulation and failed to treat syngeneic and orthotopic gliomas. We hypothesized that CAR engraftment would benefit from host lymphodepletion prior to immunotherapy and that this might be achievable by using temozolomide (TMZ), which is standard treatment for these patients and has lymphopenia as its major side effect. We modelled standard of care temozolomide (TMZSD) and dose-intensified TMZ (TMZDI) in our murine model. Both regimens are clinically approved and provide similar efficacy. Only TMZDI pretreatment prompted dramatic CAR proliferation and enhanced persistence in circulation compared to treatment with CARs alone or TMZSD + CARs. Bioluminescent imaging revealed that TMZDI + CARs induced complete regression of 21-day established brain tumors, which correlated with CAR abundance in circulation. Accordingly, TMZDI + CARs significantly prolonged survival and led to long-term survivors. These findings are highly consequential, as it suggests that GBM patients may require TMZDI as first line chemotherapy prior to systemic CAR infusion to promote CAR engraftment and antitumor efficacy. On this basis, we have initiated a phase I trial in patients with newly diagnosed GBM incorporating TMZDI as a preconditioning regimen prior to CAR immunotherapy (NCT02664363).

Percutaneous iliosacral screw placement is a technically challenging procedure with a significant complication profile for misplaced screws. The use of stereotactic image guidance has been shown to provide superior accuracy in the placement of spinal instrumentation. Here, the authors describe a novel application of O-arm technology (Medtronic Sofamor Danek, Memphis, TN, USA) to help safely place iliosacral screws for the treatment of a traumatic sacral fracture.

Immunotherapy embodies any approach that manipulates the immune system for therapeutic benefit. In this regard, various clinical trials have employed direct vaccination with patient-specific dendritic cells or adoptive T cell therapy to target highly aggressive tumors. Both modalities have demonstrated great specificity, an advantage that is unmatched by other treatment strategies. However, their full potential has yet to be realized. Areas covered: In this review, we provide an overview of chemokines in pathogen and anti-tumor immune responses and discuss further improving immunotherapies by arming particular chemokine axes. Expert commentary: The chemokine macrophage inflammatory protein-1 alpha (MIP-1α, CCL3) has emerged as a potent activator of both innate and adaptive responses. Specifically, CCL3 plays a critical role in recruiting distinct immune phenotypes to intratumoral sites, is a pivotal player in regulating lymph node homing of dendritic cell subsets, and induces antigen-specific T cell responses. The recent breadth of literature outlines the various interactions of CCL3 with these cellular subsets, which have now served as a basis for immunotherapeutic translation.

Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon's exposure to ionizing radiation is not easily recognizable without a digital dosimeter-something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure.The senior surgeon wore a digital dosimeter during all minimally invasive spine fusion procedures performed over a 12-month period. Patient demographics, procedure information, and radiation exposure throughout the procedure were recorded.Fifty-five minimally invasive spine fusions utilizing 330 percutaneous screws were included. Average radiation dose was 0.46 Rad/screw to the patient. Average radiation exposure to the surgeon was 1.06 ± 0.71 μSv/screw, with a strong positive correlation (r = 0.77) to patient dose. The coefficient of determination (rIntra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material.

Prospective chart review.It is well-known that radiation exposure during minimally invasive spine procedures can be substantial. Less interest has focused on setup radiation exposure before incision, including preoperative images used for surgical approach. The present study seeks to better quantify the significance of setup radiation in the total radiation exposure of minimally invasive spine surgery.Radiographic localization is necessary in minimally invasive spine procedures to visualize anatomy, but increased radiation exposure is associated with health risks. Preoperative imaging for anatomical localization has not been previously analyzed as an appreciable source of radiation.From an institutional review board-approved database of more than 1100 procedures, the minimally invasive spine cases with recorded set-up radiation were extracted. The total radiation, set-up radiation, and procedure type data were evaluated. Statistics were generated using a chi-squared analysis.Set-up and total radiation data were collected for 270 spine surgeries performed by four surgeons at two locations. There were 30 thoracic and 240 thoracolumbar/lumbar cases; 78 anterior and 192 posterior cases. Average total radiation (set-up and intraoperative) was 8.04 rad, and average setup radiation was 1.90 rad (28%, std 2.97 rad) across all cases. On average for the thoracolumbar/lumbar cases, set-up radiation accounted for almost 25% of total radiation with 1.76 rad from setup out of 8.16 rad total. Thoracic-only cases often necessitated even more images for localization, generating an average set-up/total percentage of 52%. Across all procedures, set-up radiation significantly increased the total radiation exposure because it accounted for more than 25% of the total procedure.Radiation exposure during preoperative localization can be substantial. Operating room personnel should recognize the high percentage of radiation that occurs during set-up, and merit should be given to techniques and technologies that can limit unnecessary radiation exposure during this portion of the procedure.2.

Rindopepimut (CDX-110) is a peptide vaccine that targets epidermal growth factor receptor variant III (EGFRvIII), a tumor-specific epitope expressed in the most common and lethal primary malignant neoplasm of the brain - glioblastoma (GBM). Areas covered: The EGFRvIII mutation introduces an 801 base pair in-frame deletion of the extracellular domain of the transmembrane tyrosine kinase, resulting in constitutive kinase activity, amplification of cell growth, and inhibition of apoptosis. Rindopepimut contains a 14mer amino acid peptide spanning the EGFRvIII mutation site that is conjugated to keyhole limpet hemocyanin (KLH). The EGFRvIII neoantigen is exclusively present on GBM cells, providing rindopepimut tumor-specific activity. The authors review rindopepimut's clinical efficacy, administration, safety, and prospects in the treatment of GBM. Expert opinion: Rindopepimut showed clinical benefit and significant efficacy in phase II clinical trials, including as part of a multi-immunotherapy approach. A phase III clinical trial was terminated early, however, as it was deemed likely the study would fail to meet its primary endpoint. Longer term and sub-group analyses will be necessary to better understand rindopepimut's future role in GBM therapy.

Pediatric emergency physicians must have a high clinical suspicion for atlantoaxial rotatory subluxation (AARS), particularly when a child presents with neck pain and an abnormal head posture without the ability to return to a neutral position. As shown in the neurosurgical literature, timely diagnosis and swift initiation of treatment have a greater chance of treatment success for the patient. However, timely treatment is complicated because torticollis can result from a variety of maladies, including: congenital abnormalities involving the C1-C2 joint or the surrounding supporting muscles and ligaments, central nervous system abnormalities, obstetric palsies from brachial plexus injuries, clavicle fractures, head and neck surgery, and infection. The treating pediatrician must discern the etiology of the underlying problem to determine both timing and treatment paradigms, which vary widely between these illnesses. We present a comprehensive review of AARS that is intended for pediatric emergency physicians. Management of AARS can vary widely bases on factors, such as duration of symptoms, as well as the patient's history. The goal of this review is to streamline the management paradigms and provide an inclusive review for pediatric emergency first responders.

A critical component of adaptive human behavior is the ability to rapidly form and update associations between environmental cues, actions, and outcomes. This form of learning provides an integral evolutionary advantage, allowing agents to reproduce behaviors that lead to rewarding outcomes more frequently while avoiding actions that may result in aversive or potentially deadly conclusions. A broad and diverse range of cognitive functions and brain regions are required to cooperatively function to produce a system that can flexibly and continuously adapt to on-going environmental and cognitive dynamics. The focus of this chapter will be to explore the neural mechanisms that underlie this cognitive process—associative learning—with a specific focus on a cluster of subcortical gray masses collectively known as the basal ganglia. We will review some of the anatomical features of the basal ganglia and recent findings of associative learning from the cellular and molecular perspective as well as findings from in vivo awake-and-behaving neurophysiological experiments in animals and humans. Finally, we will conclude with a section on dysfunctions in associative learning observed in neurological disease, spanning motor, and psychiatric disorders.

We present an unusual presentation of unstable atlanto-occipital dissociation as locked-in syndrome. Traumatic atlanto-occipital dissociation is a severe injury that accounts for 15–20% of all fatal cervical spinal injuries. A disruption occurs between the tectorial ligaments connecting the occipital condyle to the superior articulating facets of the atlas, resulting in anterior, longitudinal, or posterior translation, and it may be associated with Type III odontoid fractures. Furthermore, the dissociation may be complete (atlanto-occipital dislocation) or incomplete (atlanto-occipital subluxation), with neurologic findings ranging from normal to complete quadriplegia with respiratory compromise.

Obese patients undergoing lumbar spinal fusion surgery are a challenge to the operating surgeon. Direct lateral interbody fusion (DLIF) has been performed for degenerative disease of the lumbar spine with good outcomes; nevertheless, how obese patients fare compared to non-obese patients after DLIF remains unknown. The primary aim of this study is to compare rates of postoperative complications and long-term outcomes between obese and non-obese patients undergoing DLIF. Sixty-three patients (obese: 29, non-obese: 34) undergoing index DLIF for degenerative disease of the spine between 2010 and 2012 at our institution were retrospectively enrolled. We analyzed data on demographics, postoperative complications, back and leg pain, and functional disability over 2 years. Patients completed the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) back and leg pain numerical rating scores before surgery, then at 12 and 24 months after surgery. Outcomes and complication rates were compared between the cohorts. The cohorts were similar at baseline. Postoperative complications rates were similar between obese and non-obese patients. There was no statistically significant difference in the incidence of durotomy (p=0.91), anterior thigh numbness (p=0.60), cerebrospinal fluid leak (p=0.91), postoperative infection (p=0.37), or bleeding requiring transfusion (p=0.16). No patient experienced a nerve injury or psoas hematoma. Both cohorts had similar 2 year improvement in VAS for back pain, leg pain, and ODI. Our study demonstrates that obese and non-obese patients undergoing DLIF have similar complication profiles; hence, a patient's weight should not be a contraindication to DLIF.

INTRODUCTION:Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) is an effective immunotherapy for hematological cancers but requires a rethinking for clinical efficacy against solid tumors, where CARs have largely failed. Lymphodepletive preconditioning regimens can enhance CA

INTRODUCTION:Hospital readmission after surgery results in a substantial economic burden, and several recent studies have investigated the impact of race and ethnicity on hospital readmission rates, with the goal to identify hospitals and patients with high readmission risk.METHODS:This single-insti