Motor seizures confer overall survival benefit in who grade 2 glioma

OBJECTIVE

The prevalence of epilepsy in World Health Organization (WHO) grade 2 glioma is high, with seizures being the presenting symptom in 60%-90%. We explore the epidemiology of seizures in this patient population in a regional neurosurgical center.

METHODS

Electronic health records of patients with histologically-proven WHO grade 2 glioma (n = 228) were reviewed between 1997 and 2021, with data collected including patient demographics, epilepsy prevalence, and seizure semiology. The influence of seizure type on overall survival was calculated using a Cox proportional hazards model.

RESULTS

Overall, 197 of 228 patients (86.4%) were diagnosed with epilepsy-either at presentation or during the course of their disease. Male patients were more likely than female patients to be diagnosed with epilepsy (91.1% vs 77.1%, p = .003) and, in those with epilepsy, more likely to experience at least one focal to bilateral tonic-clonic seizure (69.4% vs 54.1%, p = .05). Patients with left-sided tumors were twice as likely to have experienced a focal to bilateral tonic-clonic seizure (p = .02, odds ratio [OR] = .47). Predominantly experiencing seizures with motor activity appeared to confer better overall survival, with a 65% decrease in the risk of death 10 years post diagnosis (hazard ratio [HR] = .35, p = .02). This is despite accounting for previously described prognostic markers including tumor histology/genetics, time from diagnosis to surgery, and the extent of tumor resection.

SIGNIFICANCE

Motor seizure activity is a frequent feature in WHO grade 2 glioma and appears to confer a survival benefit regardless of histology or surgical factors. Seizures due to dominant hemisphere tumors may be more likely to propagate and cause bilateral tonic-clonic activity.

Awake craniotomy for high-grade gliomas - a prospective cohort study in a UK tertiary-centre

BACKGROUND

Studies from the UK reporting on awake craniotomy (AC) include a heterogenous group of patients which limit the evaluation of the true impact of AC in high-grade glioma (HGG) patients. This study aims to report solely the experience and outcomes of AC for HGG surgery from our centre.

METHODS

A prospective review of all patients who underwent AC for HGG from 2013 to 2019 were performed. Data on patient characteristics including but not limited to demographics, pre- and post-operative Karnofsky performance status (KPS), tumour location and volume, type of surgery, extent of resection (EOR), tumour histopathology, intra- and post-operative complications, morbidity, mortality, disease recurrence, progression-free survival (PFS) and overall survival (OS) from the time of surgery were collected.

RESULTS

Fifteen patients (6 males; 9 females; 17 surgeries) underwent AC for HGG (median age = 55 years). Two patients underwent repeat surgeries due to disease recurrence. Median pre- and post-operative KPS score was 90 (range:80-100) and 90 (range:60-100), respectively. The EOR ranges from 60 to 100 % with a minimum of 80 % achieved in 81.3 % cases. Post-operative complications include focal seizures (17.6 %), transient aphasia/dysphasia (17.6 %), permanent motor deficit (11.8 %), transient motor deficit (5.9 %) and transient sensory disturbance (5.9 %). There were no surgery-related mortality or post-operative infection. The median PFS and OS were 13 (95%CI 5-78) and 30 (95%CI 21-78) months, respectively.

CONCLUSION

This is the first study in the UK to solely report outcomes of AC for HGG surgery. Our data demonstrates that AC for HGG in eloquent region is safe, feasible and provides comparable outcomes to those reported in the literature.

Assessing national patterns and outcomes of pituitary surgery: is hospital administrative data good enough?

PURPOSE

Patterns of surgical care, outcomes, and quality of care can be assessed using hospital administrative databases but this requires accurate and complete data. The aim of this study was to explore whether the quality of hospital administrative data was sufficient to assess pituitary surgery practice in England.

METHODS

The study analysed Hospital Episode Statistics (HES) data from April 2013 to March 2018 on all adult patients undergoing pituitary surgery in England. A series of data quality indicators examined the attribution of cases to consultants, the coding of sellar and parasellar lesions, associated endocrine and visual disorders, and surgical procedures. Differences in data quality over time and between neurosurgical units were examined.

RESULTS

A total of 5613 records describing pituitary procedures were identified. Overall, 97.3% had a diagnostic code for the tumour or lesion treated, with 29.7% (n = 1669) and 17.8% (n = 1000) describing endocrine and visual disorders, respectively. There was a significant reduction from the first to the fifth year in records that only contained a pituitary tumour code (63.7%-47.0%, p < .001). The use of procedure codes that attracted the highest tariff increased over time (66.4%-82.4%, p < .001). Patterns of coding varied widely between the 24 neurosurgical units.

CONCLUSION

The quality of HES data on pituitary surgery has improved over time but there is wide variation in the quality of data between neurosurgical units. Research studies and quality improvement programmes using these data need to check it is of sufficient quality to not invalidate their results.

Imaging Spectrum of the Developing Glioblastoma: A Cross-Sectional Observation Study

Glioblastoma (GBM) has the typical radiological appearance (TRA) of a centrally necrotic, peripherally enhancing tumor with surrounding edema. The objective of this study was to determine whether the developing GBM displays a spectrum of imaging changes detectable on routine clinical imaging prior to TRA GBM. Patients with pre-operative imaging diagnosed with GBM (1 January 2014-31 March 2022) were identified from a neuroscience center. The imaging was reviewed by an experienced neuroradiologist. Imaging patterns preceding TRA GBM were analyzed. A total of 76 out of 555 (14%) patients had imaging preceding TRA GBM, 57 had solitary lesions, and 19 had multiple lesions (total = 84 lesions). Here, 83% of the lesions had cortical or cortical/subcortical locations. The earliest imaging features for 84 lesions were T2 hyperintensity/CT low density (n = 18), CT hyperdensity (n = 51), and T2 iso-intensity (n = 15). Lesions initially showing T2 hyperintensity/CT low density later showed T2 iso-intensity. When CT and MRI were available, all CT hyperdense lesions showed T2 iso-intensity, reduced diffusivity, and the following enhancement patterns: nodular 35%, solid 29%, none 26%, and patchy peripheral 10%. The mean time to develop TRA GBM from T2 hyperintensity was 140 days and from CT hyperdensity was 69 days. This research suggests that the developing GBM shows a spectrum of imaging features, progressing through T2 hyperintensity to CT hyperdensity, T2 iso-intensity, reduced diffusivity, and variable enhancement to TRA GBM. Red flags for non-TRA GBM lesions are cortical/subcortical CT hyperdense/T2 iso-intense/low ADC. Future research correlating this imaging spectrum with pathophysiology may provide insight into GBM growth patterns.

Benchmarking short-term postoperative mortality across neurosurgery units: is hospital administrative data good enough for risk-adjustment?

BACKGROUND

Surgical mortality indicators should be risk-adjusted when evaluating the performance of organisations. This study evaluated the performance of risk-adjustment models that used English hospital administrative data for 30-day mortality after neurosurgery.

METHODS

This retrospective cohort study used Hospital Episode Statistics (HES) data from 1 April 2013 to 31 March 2018. Organisational-level 30-day mortality was calculated for selected subspecialties (neuro-oncology, neurovascular and trauma neurosurgery) and the overall cohort. Risk adjustment models were developed using multivariable logistic regression and incorporated various patient variables: age, sex, admission method, social deprivation, comorbidity and frailty indices. Performance was assessed in terms of discrimination and calibration.

RESULTS

The cohort included 49,044 patients. Overall, 30-day mortality rate was 4.9%, with unadjusted organisational rates ranging from 3.2 to 9.3%. The variables in the best performing models varied for the subspecialties; for trauma neurosurgery, a model that included deprivation and frailty had the best calibration, while for neuro-oncology a model with these variables plus comorbidity performed best. For neurovascular surgery, a simple model of age, sex and admission method performed best. Levels of discrimination varied for the subspecialties (range: 0.583 for trauma and 0.740 for neurovascular). The models were generally well calibrated. Application of the models to the organisation figures produced an average (median) absolute change in mortality of 0.33% (interquartile range (IQR) 0.15-0.72) for the overall cohort model. Median changes for the subspecialty models were 0.29% (neuro-oncology, IQR 0.15-0.42), 0.40% (neurovascular, IQR 0.24-0.78) and 0.49% (trauma neurosurgery, IQR 0.23-1.68).

CONCLUSIONS

Reasonable risk-adjustment models for 30-day mortality after neurosurgery procedures were possible using variables from HES, although the models for trauma neurosurgery performed less well. Including a measure of frailty often improved model performance.

The management of incidental meningioma: An unresolved clinical conundrum

The widespread availability and use of brain magnetic resonance imaging and computed tomography has led to an increase in the frequency of incidental meningioma diagnoses. Most incidental meningioma are small, demonstrate indolent behavior during follow-up, and do not require intervention. Occasionally, meningioma growth causes neurological deficits or seizures prompting surgical or radiation treatment. They may cause anxiety to the patient and present a management dilemma for the clinician. The questions for both patient and clinician are "will the meningioma grow and cause symptoms such that it will require treatment within my lifetime?" and "will deferment of treatment result in greater treatment-related risks and lower chance of cure?." International consensus guidelines recommend regular imaging and clinical follow-up, but the duration is not specified. Upfront treatment with surgery or stereotactic radiosurgery/radiotherapy may be recommended but this is potentially an overtreatment, and its benefits must be balanced against the risk of related adverse events. Ideally, treatment should be stratified based on patient and tumor characteristics, but this is presently hindered by low-quality supporting evidence. This review discusses risk factors for meningioma growth, proposed management strategies, and ongoing research in the field.

Do animal models of brain tumors replicate human peritumoral edema? a systematic literature search

INTRODUCTION

Brain tumors cause morbidity and mortality in part through peritumoral brain edema. The current main treatment for peritumoral brain edema are corticosteroids. Due to the increased recognition of their side-effect profile, there is growing interest in finding alternatives to steroids but there is little formal study of animal models of peritumoral brain edema. This study aims to summarize the available literature.

METHODS

A systematic search was undertaken of 5 literature databases (Medline, Embase, CINAHL, PubMed and the Cochrane Library). The generic strategy was to search for various terms associated with "brain tumors", "brain edema" and "animal models".

RESULTS

We identified 603 reports, of which 112 were identified as relevant for full text analysis that studied 114 peritumoral brain edema animal models. We found significant heterogeneity in the species and strain of tumor-bearing animals, tumor implantation method and edema assessment. Most models did not produce appreciable brain edema and did not test for observable manifestations thereof.

CONCLUSION

No animal model currently exists that enable the investigation of novel candidates for the treatment of peritumoral brain edema. With current interest in alternative treatments for peritumoral brain edema, there is an unmet need for clinically relevant animal models.

ASPECT Score and Its Application to Vasospasm in Aneurysmal Subarachnoid Haemorrhage: a Case-Control Study

Delayed cerebral ischaemia (DCI) is a significant complication of aneurysmal subarachnoid haemorrhage (aSAH) and is strongly associated with poorer outcome. The Alberta Stroke Program Early Computer Tomography (ASPECT) score is an established scoring tool, used in acute ischaemic stroke, to quantify early ischaemic changes on CT head scans. We aim to identify if ASPECT scoring correlates with functional outcome in DCI following aSAH. Retrospective case-control study. Inclusion criteria: admission to the Department of Neurosurgery at Leeds Teaching Hospitals NHS Trust (a tertiary neurosurgical centre in the United Kingdom) between 2014 and 2018, with a diagnosis of anterior circulation aneurysmal subarachnoid haemorrhage; as confirmed by initial CT scan and subsequent CT angiography or catheter digital subtraction angiography. Cases were those who developed DCI (n = 43) and controls were randomly selected from those who did not develop DCI (n = 46) but otherwise met the same inclusion criteria. The primary outcome measure was Glasgow Outcome Score (GOS): assessed at discharge and 3 months. ASPECT scores were calculated from non-contrast CT head scans by three researchers blinded to each other and clinical outcome. Spearman's rank correlation was used to calculate correlation between ASPECT scores and GOS. ASPECT score positively correlated with GOS in the cases both at discharge (Spearman rho 0.436, p = 0.003) and at 3 months (Spearman rho 0.431, p = 0.004). When corrected for Fisher grading, the adjusted odds ratio of having a high GOS with a low ASPECT score at discharge was OR 0.74 (95% CI 0.61-0.94, p = 0.003), and 3 months OR 0.73 (95% CI 0.59-0.91, p = 0.005). ASPECT score significantly correlates with clinical outcome in DCI post aSAH, even after correcting for Fisher grade. ASPECT scoring may identify patients at risk of poor outcome following DCI and represents a quick and reliable tool that aids in clinical decision-making and prognostication.

Mortality as an indicator of quality of neurosurgical care in England: a retrospective cohort study

OBJECTIVES

Postoperative mortality is a widely used quality indicator, but it may be unreliable when procedure numbers and/or mortality rates are low, due to insufficient statistical power. The objective was to investigate the statistical validity of postoperative 30-day mortality as a quality metric for neurosurgical practice across healthcare providers.

DESIGN

Retrospective cohort study.

SETTING

Hospital Episode Statistics data from all neurosurgical units in England.

PARTICIPANTS

Patients who underwent neurosurgical procedures between April 2013 and March 2018. Procedures were grouped using the National Neurosurgical Audit Programme classification.

OUTCOMES MEASURED

National 30-day postoperative mortality rates were calculated for elective and non-elective neurosurgical procedural groups. The study estimated the proportion of neurosurgeons and NHS trusts in England that performed sufficient procedures in 3-year and 5-year periods to detect unusual performance (defined as double the national rate of mortality). The actual difference in mortality rates that could be reliably detected based on procedure volumes of neurosurgeons and units over a 5-year period was modelled.

RESULTS

The 30-day mortality rates for all elective and non-elective procedures were 0.4% and 6.1%, respectively. Only one neurosurgeon in England achieved the minimum sample size (n=2402) of elective cases in 5 years needed to detect if their mortality rate was double the national average. All neurosurgical units achieved the minimum sample sizes for both elective (n=2402) and non-elective (n=149) procedures. In several neurosurgical subspecialties, approximately 80% of units (or more) achieved the minimum sample sizes needed to detect if their mortality rate was double the national rate, including elective neuro-oncology (baseline mortality rate=2.3%), non-elective neuro-oncology (rate=5.7%), neurovascular (rate=6.7%) and trauma (rate=11%).

CONCLUSION

Postoperative mortality lacks statistical power as a measure of individual neurosurgeon performance. Neurosurgical units in England performed sufficient procedure numbers overall and in several subspecialty areas to support the use of mortality as a quality indicator.

Imaging timing after glioblastoma surgery (INTERVAL-GB): protocol for a UK and Ireland, multicentre retrospective cohort study

INTRODUCTION

Glioblastoma is the most common malignant primary brain tumour with a median overall survival of 12-15 months (range 6-17 months), even with maximal treatment involving debulking neurosurgery and adjuvant concomitant chemoradiotherapy. The use of postoperative imaging to detect progression is of high importance to clinicians and patients, but currently, the optimal follow-up schedule is yet to be defined. It is also unclear how adhering to National Institute for Health and Care Excellence (NICE) guidelines-which are based on general consensus rather than evidence-affects patient outcomes such as progression-free and overall survival. The primary aim of this study is to assess MRI monitoring practice after surgery for glioblastoma, and to evaluate its association with patient outcomes.

METHODS AND ANALYSIS

ImagiNg Timing aftER surgery for glioblastoma: an eVALuation of practice in Great Britain and Ireland is a retrospective multicentre study that will include 450 patients with an operated glioblastoma, treated with any adjuvant therapy regimen in the UK and Ireland. Adult patients ≥18 years diagnosed with glioblastoma and undergoing surgery between 1 August 2018 and 1 February 2019 will be included. Clinical and radiological scanning data will be collected until the date of death or date of last known follow-up. Anonymised data will be uploaded to an online Castor database. Adherence to NICE guidelines and the effect of being concordant with NICE guidelines will be identified using descriptive statistics and Kaplan-Meier survival analysis.

ETHICS AND DISSEMINATION

Each participating centre is required to gain local institutional approval for data collection and sharing. Formal ethical approval is not required since this is a service evaluation. Results of the study will be reported through peer-reviewed presentations and articles, and will be disseminated to participating centres, patients and the public.

A Delphi consensus statement for digital surgery

The use of digital technology is increasing rapidly across surgical specialities, yet there is no consensus for the term ‘digital surgery’. This is critical as digital health technologies present technical, governance, and legal challenges which are unique to the surgeon and surgical patient. We aim to define the term digital surgery and the ethical issues surrounding its clinical application, and to identify barriers and research goals for future practice. 38 international experts, across the fields of surgery, AI, industry, law, ethics and policy, participated in a four-round Delphi exercise. Issues were generated by an expert panel and public panel through a scoping questionnaire around key themes identified from the literature and voted upon in two subsequent questionnaire rounds. Consensus was defined if >70% of the panel deemed the statement important and <30% unimportant. A final online meeting was held to discuss consensus statements. The definition of digital surgery as the use of technology for the enhancement of preoperative planning, surgical performance, therapeutic support, or training, to improve outcomes and reduce harm achieved 100% consensus agreement. We highlight key ethical issues concerning data, privacy, confidentiality and public trust, consent, law, litigation and liability, and commercial partnerships within digital surgery and identify barriers and research goals for future practice. Developers and users of digital surgery must not only have an awareness of the ethical issues surrounding digital applications in healthcare, but also the ethical considerations unique to digital surgery. Future research into these issues must involve all digital surgery stakeholders including patients.

Day 2 neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios for prediction of delayed cerebral ischemia in subarachnoid hemorrhage

OBJECTIVE

Recent evidence has suggested that an admission neutrophil-to-lymphocyte ratio (NLR) of ≥ 5.9 predicts delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH). The primary aims of this study were to assess reproducibility and to ascertain the predictive ability of NLR on subsequent days postictus. Secondary aims included identification of additional inflammatory markers.

METHODS

A single-center, retrospective study of all patients aged ≥ 18 years with aSAH between May 2014 and July 2018 was performed. Patient characteristics, DCI incidence, operative features, and outcomes (on discharge and at 3 months postictus) were recorded. C-reactive protein (CRP) and full blood count differentials were recorded on admission and through day 8 postictus or at discharge. In total, 403 patients were included in the final analysis.

RESULTS

Ninety-six patients (23.8%) developed DCI with a median time from ictus of 6 days (IQR 3.25–8 days). A platelet-to-lymphocyte ratio (PLR) cutoff ≥ 157 and CRP cutoff ≥ 27 was used in our cohort. In a multiple binary logistic regression model, after controlling for known DCI predictors, day 2 NLR ≥ 5.9 (OR 2.194, 95% CI 1.099–4.372; p = 0.026), day 1 PLR ≥ 157 (OR 2.398, 95% CI 1.1072–5.361; p = 0.033), day 2 PLR ≥ 157 (OR 2.676, 95% CI 1.344–5.329; p = 0.005), and CRP ≥ 27 on days 3, 4, and 5 were predictive of DCI.

CONCLUSIONS

The results of this study have confirmed the association between NLR and DCI and have demonstrated the predictive potential of PLR and CRP, suggesting that NLR and PLR at day 2, and CRP from day 3 onward, may be better predictors of DCI than those measurements at the time of ictus.

Patterns and outcomes of neurosurgery in England over a five-year period: A national retrospective cohort study

BACKGROUND

Neurosurgical practice has seen major changes over several decades. There are no recent evaluations of national neurosurgical practice. The aim of this observational study was to describe neurosurgical practice in England and to use outcomes to assess and benchmark the quality of care in neurosurgery.

MATERIAL AND METHODS

This national retrospective cohort study analysed Hospital Episode Statistics (HES) data from April 2013 to March 2018 for all adult admissions with a specialty code for neurosurgery. The epidemiology of patients and RCS Charlson comorbidities were derived and procedure incidence rates per 100,000 person-years calculated. Post-operative outcomes for elective and non-elective patients included: median length of stay, the proportion of patients requiring additional inpatient neurosurgical procedures, the proportion of patients discharged to their usual address, and in-hospital mortality rates.

RESULTS

During the 5-year study period, there were 371,418 admissions to neurosurgery. The proportion of admissions involving a neurosurgical procedure was 77.3% (n = 287,077). Of these, 45% were for cranial surgery and 37% for spinal. Overall, 68.3% were elective procedures. The incidence rates of most procedures were low (<20 per 100,000 person-years). Following elective neurosurgical procedures, in-hospital mortality rates for cranial and spinal surgery were 0.5% (95% CI, 0.5-0.6) and 0.1% (95% CI, 0.04-0.1), respectively. After non-elective neurosurgery, mortality rates were 7.4% (95% CI, 7.2-7.6) and 1.3% (95% CI, 1.2-1.5) for cranial and spinal surgery, respectively. Approximately 1 in 4 patients had additional procedures following non-elective cranial surgery (24%; 95% CI, 23.6-24.3). Outcomes were highly variable across different subspecialty areas.

CONCLUSIONS

The incidence rates of neurosurgical procedures are low within England, and neurosurgical units have a high volume of non-surgical admissions. In-hospital mortality rates after elective neurosurgery are low but there may be opportunities for quality improvement programmes to improve outcomes for non-elective surgery as well as ensuring equitable access to treatment.

External validation and recalibration of an incidental meningioma prognostic model - IMPACT: protocol for an international multicentre retrospective cohort study

INTRODUCTION

Due to the increased use of CT and MRI, the prevalence of incidental findings on brain scans is increasing. Meningioma, the most common primary brain tumour, is a frequently encountered incidental finding, with an estimated prevalence of 3/1000. The management of incidental meningioma varies widely with active clinical-radiological monitoring being the most accepted method by clinicians. Duration of monitoring and time intervals for assessment, however, are not well defined. To this end, we have recently developed a statistical model of progression risk based on single-centre retrospective data. The model Incidental Meningioma: Prognostic Analysis Using Patient Comorbidity and MRI Tests (IMPACT) employs baseline clinical and imaging features to categorise the patient with an incidental meningioma into one of three risk groups: low, medium and high risk with a proposed active monitoring strategy based on the risk and temporal trajectory of progression, accounting for actuarial life expectancy. The primary aim of this study is to assess the external validity of this model.

METHODS AND ANALYSIS

IMPACT is a retrospective multicentre study which will aim to include 1500 patients with an incidental intracranial meningioma, powered to detect a 10% progression risk. Adult patients ≥16 years diagnosed with an incidental meningioma between 1 January 2009 and 31 December 2010 will be included. Clinical and radiological data will be collected longitudinally until the patient reaches one of the study endpoints: intervention (surgery, stereotactic radiosurgery or fractionated radiotherapy), mortality or last date of follow-up. Data will be uploaded to an online Research Electronic Data Capture database with no unique identifiers. External validity of IMPACT will be tested using established statistical methods.

ETHICS AND DISSEMINATION

Local institutional approval at each participating centre will be required. Results of the study will be reported through peer-reviewed articles and conferences and disseminated to participating centres, patients and the public using social media.

Challenges and opportunities in academic neurosurgery

Clinical academia aims to bridge the gap between clinicians and scientists, by combining academic activity with clinical practice. The term 'clinical academics' generally refers to clinicians who have protected time within their job plans for undertaking academic activities. Engagement with academic activity by trainees is not only essential to fulfil necessary curriculum competencies, but also allows them to explore areas of interest outside of clinical practice and develop advanced academic skills. This article provides an overview of different routes into academic neurosurgery, and discusses the advantages and difficulties in pursuing this career path. It also covers the differences between postgraduate research degrees and explores the different job plan models available at consultant level. Academic neurosurgery is a rewarding career and opportunities should be made available to those who wish to explore it further. Developing academic careers may have a positive impact on wider workforce planning strategies and improve the delivery of high-quality evidence-based neurosurgical care.

Polyelectrolyte complex templated synthesis of monodisperse, sub-100 nm porous silica nanoparticles for cancer targeted and stimuli-responsive drug delivery

Porous silica nanoparticles (PSiNPs) have long attracted interest in drug delivery research. However, conventional synthesis methods for sub-100 nm, functionalised PSiNPs typically give poor monodispersity, reproducibility, or involve complex synthetic protocols. We report a facile, reproducible, and cost-effective one-pot method for the synthesis of cancer targeting and pH responsive PSiNPs in this size range, without the need for post-synthetic modification. This was achieved by using monodisperse l-arginine (Arg)/ poly(acrylic acid) (PAA) polyelectrolyte complexes (PECs) as soft templates for silane hydrolysis and condensation. Highly uniform PSiNPs with tunable size control between 42 and 178 nm and disordered pore structure (1.1-2.7 nm) were obtained. Both PAA and Arg were retained within the PSiNPs, which enabled a high doxorubicin hydrochloride (Dox) loading capacity (22% w/w) and a 4-fold increase in drug release under weakly acidic pH compared to physiological pH. The surface presentation of Arg conferred significantly higher intracellular accumulation of Arg/PAA-PSiNPs in patient-derived glioblastoma cells compared to non-tumorigenic neural progenitor cells, which effectively translated to lower IC50 values for Dox-loaded Arg/PAA-PSiNPs than non-functionalised PSiNPs. This work brings forward new insights for the development of monodisperse PSiNPs with highly desirable built-in functionalities for biomedical applications.

Impact of COVID-19 pandemic on surgical neuro-oncology multi-disciplinary team decision making: a national survey (COVID-CNSMDT Study)

OBJECTIVES

Pressures on healthcare systems due to COVID-19 has impacted patients without COVID-19 with surgery disproportionally affected. This study aims to understand the impact on the initial management of patients with brain tumours by measuring changes to normal multidisciplinary team (MDT) decision making.

DESIGN

A prospective survey performed in UK neurosurgical units performed from 23 March 2020 until 24 April 2020.

SETTING

Regional neurosurgical units outside London (as the pandemic was more advanced at time of study).

PARTICIPANTS

Representatives from all units were invited to collect data on new patients discussed at their MDT meetings during the study period. Each unit decided if management decision for each patient had changed due to COVID-19.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measures included number of patients where the decision to undergo surgery changed compared with standard management usually offered by that MDT. Secondary outcome measures included changes in surgical extent, numbers referred to MDT, number of patients denied surgery not receiving any treatment and reasons for any variation across the UK.

RESULTS

18 units (75%) provided information from 80 MDT meetings that discussed 1221 patients. 10.7% of patients had their management changed-the majority (68%) did not undergo surgery and more than half of this group not undergoing surgery had no active treatment. There was marked variation across the UK (0%-28% change in management). Units that did not change management could maintain capacity with dedicated oncology lists. Low volume units were less affected.

CONCLUSION

COVID-19 has had an impact on patients requiring surgery for malignant brain tumours, with patients receiving different treatments-most commonly not receiving surgery or any treatment at all. The variations show dedicated cancer operating lists may mitigate these pressures.

STUDY REGISTRATION

This study was registered with the Royal College of Surgeons of England's COVID-19 Research Group (https://www.rcseng.ac.uk/coronavirus/rcs-covid-research-group/).

Hematopoietic Stem Cell Gene Therapy for Brain Metastases Using Myeloid Cell-Specific Gene Promoters

BACKGROUND

Brain metastases (BrM) develop in 20-40% of cancer patients and represent an unmet clinical need. Limited access of drugs into the brain because of the blood-brain barrier is at least partially responsible for therapeutic failure, necessitating improved drug delivery systems.

METHODS

Green fluorescent protein (GFP)-transduced murine and nontransduced human hematopoietic stem cells (HSCs) were administered into mice (n = 10 and 3). The HSC progeny in mouse BrM and in patient-derived BrM tissue (n = 6) was characterized by flow cytometry and immunofluorescence. Promoters driving gene expression, specifically within the BrM-infiltrating HSC progeny, were identified through differential gene-expression analysis and subsequent validation of a series of promoter-green fluorescent protein-reporter constructs in mice (n = 5). One of the promoters was used to deliver tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to BrM in mice (n = 17/21 for TRAIL vs control group).

RESULTS

HSC progeny (consisting mostly of macrophages) efficiently homed to macrometastases (mean [SD] = 37.6% [7.2%] of all infiltrating cells for murine HSC progeny; 27.9% mean [SD] = 27.9% [4.9%] of infiltrating CD45+ hematopoietic cells for human HSC progeny) and micrometastases in mice (19.3-53.3% of all macrophages for murine HSCs). Macrophages were also abundant in patient-derived BrM tissue (mean [SD] = 8.8% [7.8%]). Collectively, this provided a rationale to optimize the delivery of gene therapy to BrM within myeloid cells. MMP14 promoter emerged as the strongest promoter construct capable of limiting gene expression to BrM-infiltrating myeloid cells in mice. TRAIL delivered under MMP14 promoter statistically significantly prolonged survival in mice (mean [SD] = 19.0 [3.4] vs mean [SD] = 15.0 [2.0] days for TRAIL vs control group; two-sided P = .006), demonstrating therapeutic and translational potential of our approach.

CONCLUSIONS

Our study establishes HSC gene therapy using a myeloid cell-specific promoter as a new strategy to target BrM. This approach, with strong translational value, has potential to overcome the blood-brain barrier, target micrometastases, and control multifocal lesions.

Chemically induced neurite-like outgrowth reveals a multicellular network function in patient-derived glioblastoma cells

Tumor stem cells and malignant multicellular networks have been separately implicated in the therapeutic resistance of glioblastoma multiforme (GBM), the most aggressive type of brain cancer in adults. Here, we show that small-molecule inhibition of RHO-associated serine/threonine kinase proteins (ROCKi) significantly promoted the outgrowth of neurite-like cell projections in cultures of heterogeneous patient-derived GBM stem-like cells. These projections formed de novo-induced cellular network (iNet) 'webs', which regressed after withdrawal of ROCKi. Connected cells within the iNet web exhibited long range Ca²⁺ signal transmission, and significant lysosomal and mitochondrial trafficking. In contrast to their less-connected vehicle control counterparts, iNet cells remained viable and proliferative after high-dose radiation. These findings demonstrate a link between ROCKi-regulated cell projection dynamics and the formation of radiation-resistant multicellular networks. Our study identifies means to reversibly induce iNet webs ex vivo, and may thereby accelerate future studies into the biology of GBM cellular networks.

KHS101 disrupts energy metabolism in human glioblastoma cells and reduces tumor growth in mice

Pharmacological inhibition of uncontrolled cell growth with small-molecule inhibitors is a potential strategy for treating glioblastoma multiforme (GBM), the most malignant primary brain cancer. We showed that the synthetic small-molecule KHS101 promoted tumor cell death in diverse GBM cell models, independent of their tumor subtype, and without affecting the viability of noncancerous brain cell lines. KHS101 exerted cytotoxic effects by disrupting the mitochondrial chaperone heat shock protein family D member 1 (HSPD1). In GBM cells, KHS101 promoted aggregation of proteins regulating mitochondrial integrity and energy metabolism. Mitochondrial bioenergetic capacity and glycolytic activity were selectively impaired in KHS101-treated GBM cells. In two intracranial patient-derived xenograft tumor models in mice, systemic administration of KHS101 reduced tumor growth and increased survival without discernible side effects. These findings suggest that targeting of HSPD1-dependent metabolic pathways might be an effective strategy for treating GBM.

Diffuse Intrinsic Pontine Glioma : Clinical Features, Molecular Genetics, and Novel Targeted Therapeutics

Diffuse intrinsic pontine glioma (DIPG) is a deadly paediatric brain cancer. Transient response to radiation, ineffective chemotherapeutic agents and aggressive biology result in rapid progression of symptoms and a dismal prognosis. Increased availability of tumour tissue has enabled the identification of histone gene aberrations, genetic driver mutations and methylation changes, which have resulted in molecular and phenotypic subgrouping. However, many of the underlying mechanisms of DIPG oncogenesis remain unexplained. It is hoped that more representative in vitro and preclinical models–using both xenografted material and genetically engineered mice–will enable the development of novel chemotherapeutic agents and strategies for targeted drug delivery. This review provides a clinical overview of DIPG, the barriers to progress in developing effective treatment, updates on drug development and preclinical models, and an introduction to new technologies aimed at enhancing drug delivery.

Spontaneous Glioblastoma Spheroid Infiltration of Early-Stage Cerebral Organoids Models Brain Tumor Invasion

Organoid methodology provides a platform for the ex vivo investigation of the cellular and molecular mechanisms underlying brain development and disease. The high-grade brain tumor glioblastoma multiforme (GBM) is considered a cancer of unmet clinical need, in part due to GBM cell infiltration into healthy brain parenchyma, making complete surgical resection improbable. Modeling the process of GBM invasion in real time is challenging as it requires both tumor and neural tissue compartments. Here, we demonstrate that human GBM spheroids possess the ability to spontaneously infiltrate early-stage cerebral organoids (eCOs). The resulting formation of hybrid organoids demonstrated an invasive tumor phenotype that was distinct from noncancerous adult neural progenitor (NP) spheroid incorporation into eCOs. These findings provide a basis for the modeling and quantification of the GBM infiltration process using a stem-cell-based organoid approach, and may be used for the identification of anti-GBM invasion strategies.

Intravenous delivery of oncolytic reovirus to brain tumor patients immunologically primes for subsequent checkpoint blockade

Immune checkpoint inhibitors, including those targeting programmed cell death protein 1 (PD-1), are reshaping cancer therapeutic strategies. Evidence suggests, however, that tumor response and patient survival are determined by tumor programmed death ligand 1 (PD-L1) expression. We hypothesized that preconditioning of the tumor immune microenvironment using targeted, virus-mediated interferon (IFN) stimulation would up-regulate tumor PD-L1 protein expression and increase cytotoxic T cell infiltration, improving the efficacy of subsequent checkpoint blockade. Oncolytic viruses (OVs) represent a promising form of cancer immunotherapy. For brain tumors, almost all studies to date have used direct intralesional injection of OV, because of the largely untested belief that intravenous administration will not deliver virus to this site. We show, in a window-of-opportunity clinical study, that intravenous infusion of oncolytic human Orthoreovirus (referred to herein as reovirus) leads to infection of tumor cells subsequently resected as part of standard clinical care, both in high-grade glioma and in brain metastases, and increases cytotoxic T cell tumor infiltration relative to patients not treated with virus. We further show that reovirus up-regulates IFN-regulated gene expression, as well as the PD-1/PD-L1 axis in tumors, via an IFN-mediated mechanism. Finally, we show that addition of PD-1 blockade to reovirus enhances systemic therapy in a preclinical glioma model. These results support the development of combined systemic immunovirotherapy strategies for the treatment of both primary and secondary tumors in the brain.

Cervical spinal glioblastoma multiforme in the elderly

Spinal glioblastoma multiforme (GBM) is uncommon, and its diagnosis may be challenging. This is especially true in the elderly population. Best management strategy remains to be defined. The purpose of this report is to document this rare condition, increase awareness (as a potential differential diagnosis) and propose treatment options in the elderly; a review of the relevant literature is included. A biopsy may be beneficial in given circumstances as cervical spinal GBM carries a better prognosis compared with intramedullary metastasis.

Comparison of vertebroplasty using directional versus straight needle

Background

Percutaneous vertebroplasty is a minimally invasive procedure that can be performed to treat pain and immobility associated with vertebral compression fractures. Previous studies have shown that a single injection can achieve adequate fill across the midline of the vertebral body.

Purpose

To compare the radiological outcomes of using a novel steerable needle with using a conventional, straight needle in unipedicular vertebroplasty.

Material and Methods

Data were collected from 19 patients who were operated at our institute between 1 September 2010 and 31 March 2011. Outcomes were measured in terms of radiological evidence of midline crossing of cement. The available pre- and postoperative pain scores and complications were reviewed. Student’s t-test was used to compare mean cement projection across the midline in both groups with P < 0.05 considered to be statistically significant

Results

Mean fill across the midline was significantly greater with the steerable needle (58%) compared with the straight needle (35%) (P = 0.046). Cement leakage was higher with the steerable needle (44% versus 30%); however no clinical complications were reported in either group.

Conclusion

Percutaneous vertebroplasty using a directional needle is an excellent example of advancement and refinement in spinal surgery without increased clinical risk. Our results indicate that the novel technique can potentially provide better radiological outcomes when compared with a straight needle. A larger, randomized multicenter prospective trial would be valuable in confirming these findings.