Medical management and surgery versus medical management alone for symptomatic cerebral cavernous malformation (CARE): a feasibility study and randomised, open, pragmatic, pilot phase trial

BACKGROUND

The highest priority uncertainty for people with symptomatic cerebral cavernous malformation is whether to have medical management and surgery or medical management alone. We conducted a pilot phase randomised controlled trial to assess the feasibility of addressing this uncertainty in a definitive trial.

METHODS

The CARE pilot trial was a prospective, randomised, open-label, assessor-blinded, parallel-group trial at neuroscience centres in the UK and Ireland. We aimed to recruit 60 people of any age, sex, and ethnicity who had mental capacity, were resident in the UK or Ireland, and had a symptomatic cerebral cavernous malformation. Computerised, web-based randomisation assigned participants (1:1) to medical management and surgery (neurosurgical resection or stereotactic radiosurgery) or medical management alone, stratified by the neurosurgeon's and participant's consensus about the intended type of surgery before randomisation. Assignment was open to investigators, participants, and carers, but not clinical outcome event adjudicators. Feasibility outcomes included site engagement, recruitment, choice of surgical management, retention, adherence, data quality, clinical outcome event rate, and protocol implementation. The primary clinical outcome was symptomatic intracranial haemorrhage or new persistent or progressive non-haemorrhagic focal neurological deficit due to cerebral cavernous malformation or surgery during at least 6 months of follow-up. We analysed data from all randomly assigned participants according to assigned management. This trial is registered with ISRCTN (ISRCTN41647111) and has been completed.

FINDINGS

Between Sept 27, 2021, and April 28, 2023, 28 (70%) of 40 sites took part, at which investigators screened 511 patients, of whom 322 (63%) were eligible, 202 were approached for recruitment, and 96 had collective uncertainty with their neurosurgeon about whether to have surgery for a symptomatic cerebral cavernous malformation. 72 (22%) of 322 eligible patients were randomly assigned (mean recruitment rate 0·2 [SD 0·25] participants per site per month) at a median of 287 (IQR 67-591) days since the most recent symptomatic presentation. Participants' median age was 50·6 (IQR 38·6-59·2) years, 68 (94%) of 72 participants were adults, 41 (57%) were female, 66 (92%) were White, 56 (78%) had a previous intracranial haemorrhage, and 28 (39%) had a previous epileptic seizure. The intended type of surgery before randomisation was neurosurgical resection for 19 (26%) of 72, stereotactic radiosurgery for 44 (61%), and no preference for nine (13%). Baseline clinical and imaging data were complete for all participants. 36 participants were randomly assigned to medical management and surgery (12 to neurosurgical resection and 24 to stereotactic radiosurgery) and 36 to medical management alone. Three (4%) of 72 participants withdrew, one was lost to follow-up, and one declined face-to-face follow-up, leaving 67 (93%) retained at 6-months' clinical follow-up. 61 (91%) of 67 participants with follow-up adhered to the assigned management strategy. The primary clinical outcome occurred in two (6%) of 33 participants randomly assigned to medical management and surgery (8·0%, 95% CI 2·0-32·1 per year) and in two (6%) of 34 participants randomly assigned to medical management alone (7·5%, 1·9-30·1 per year). Investigators reported no deaths, no serious adverse events, one protocol violation, and 61 protocol deviations.

INTERPRETATION

This pilot phase trial exceeded its recruitment target, but a definitive trial will require extensive international engagement.

FUNDING

National Institute for Health and Care Research.

IDHwt glioblastomas can be stratified by their transcriptional response to standard treatment, with implications for targeted therapy

BACKGROUND

Glioblastoma (GBM) brain tumors lacking IDH1 mutations (IDHwt) have the worst prognosis of all brain neoplasms. Patients receive surgery and chemoradiotherapy but tumors almost always fatally recur.

RESULTS

Using RNA sequencing data from 107 pairs of pre- and post-standard treatment locally recurrent IDHwt GBM tumors, we identify two responder subtypes based on longitudinal changes in gene expression. In two thirds of patients, a specific subset of genes is upregulated from primary to recurrence (Up responders), and in one third, the same genes are downregulated (Down responders), specifically in neoplastic cells. Characterization of the responder subtypes indicates subtype-specific adaptive treatment resistance mechanisms that are associated with distinct changes in the tumor microenvironment. In Up responders, recurrent tumors are enriched in quiescent proneural GBM stem cells and differentiated neoplastic cells, with increased interaction with the surrounding normal brain and neurotransmitter signaling, whereas Down responders commonly undergo mesenchymal transition. ChIP-sequencing data from longitudinal GBM tumors suggests that the observed transcriptional reprogramming could be driven by Polycomb-based chromatin remodeling rather than DNA methylation.

CONCLUSIONS

We show that the responder subtype is cancer-cell intrinsic, recapitulated in in vitro GBM cell models, and influenced by the presence of the tumor microenvironment. Stratifying GBM tumors by responder subtype may lead to more effective treatment.

A Retrospective Review of the Clinical Outcomes of Lung Cancer Patients Referred into the Regional Neuro-Oncology Pathway in 2020 in Merseyside, United Kingdom

AIMS

The aim of this project was to review the outcomes of patients referred via our regional neuro-oncology pathway who received neurosurgery, SRS, whole brain radiotherapy (WBRT), chemotherapy (SACT) or best supportive care (BSC).

METHOD

All lung cancer patients discussed at our Neuro-Oncology MDT in 2020 were identified. Patient characteristics and outcomes were obtained from the regional lung and neuro-oncology MDT notes and electronic case notes from Clatterbridge Cancer Centre. Overall survival (OS) was calculated from the date of diagnostic scan to death. The date of data cut-off was 15/10/2021.

RESULTS

Full datasets were available for 100 patients discussed at the Neuro-Oncology MDT. 65 were adenocarcinomas, 4 had ALK or EGFR mutations and 49 were synchronously presenting with brain metastases and lung cancer. At data cut-off 84 deaths had occurred. The median OS in days was calculated for surgery (207), SRS (360), surgery and cavity boost (298), SACT (249), WBRT (102) and BSC (60). A grouped comparison of SRS and surgery versus other interventions or best supportive care found a statistically significant advantage favouring SRS or surgery (Median OS 360 days, p=0.001). When comparing the synchronous versus asynchronous setting, the combined median OS of the neurosurgical, SRS or SACT cohorts was 276 versus 170 days but there was no difference in WBRT or BSC.

CONCLUSION

This real-world data details the number of lung cancer patients referred to and receiving neurosurgery or SRS via the Merseyside neuro-oncology MDT. This data supports pre-existing evidence that those who receive SRS or neurosurgery have a superior OS.

The Measurement and Reporting of Outcomes in Clinical Studies of Incidental and Untreated Meningioma Are Heterogeneous and Prevent Knowledge Progress: A Systematic Review

AIMS

There is increasing interest in the clinical management of patients with incidental and untreated intracranial meningioma. Determining balance between observation and intervention is a key research priority. However, heterogeneity of outcome measurement and reporting has hampered knowledge progress. This systematic review aimed to summarise the outcomes measured and reported in such studies.

METHOD

A systematic literature search was performed to identify published full-texts describing active monitoring of adult cohorts with incidental and untreated intracranial meningioma. Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Deduplication, grouping, and classification of verbatim outcomes was performed to identify unique outcomes reported in the literature.

RESULTS

Thirty-three published articles and one ongoing study were included, describing 32 unique studies: retrospective n=27, cross-sectional n=3, prospective n=2. 271 verbatim outcomes were reported, of which 90 were defined. Following deduplication, 181 unique verbatim outcomes remained and were grouped into 53 unique ‘non-verbatim’ outcomes. Those reported most frequently included: volume of tumor n=18, growth of tumor n=30, absolute growth rate n=18, relative growth rate n=17, need for surgery n=21, and progression-free survival n=11.

CONCLUSION

Harmonisation of outcome measurement and reporting across clinical studies of incidental and untreated intracranial meningioma could facilitate knowledge progress for this priority research area. The unique outcomes identified from this systematic literature review will be prioritised through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a Core Outcome Set (COS) for use in future clinical studies.

Newly Diagnosed Brain Tumours: When Is a Staging CT Required?

AIMS

Newly diagnosed brain lesions (NBL) on imaging can be either primary or secondary in nature. Of these, only secondary brain lesions routinely require a staging CT chest, abdomen, and pelvis (CTCAP). But owing to lack of clear guidelines, all NBLs usually receive a staging investigation. This leads to over investigation of primary brain tumors. We sought to identify predictors of secondary brain lesions using CT head alone to guide the selection of patients for a CTCAP.

METHOD

Patients with NBLs referred to a tertiary Neurosurgical centre were reviewed. For protocol creation, data was collected from patients referred between July to December 2020, potential predictor variables were identified. Potential candidate protocols identified were assessed in a protocol-testing stage using data from a different set of patients. Sensitivity, specificity, and area under the curve (AUC) values were computed for each protocol.

RESULTS

The protocol-creation stage included 222 patients. Multivariate logistic regression analysis identified candidate protocols. This identified the most sensitive predictors of metastatic disease as : a previous history of cancer, multiple lesions, lesion size <4cm, and infratentorial location. A final protocol identified was found to have a sensitivity of 99.1% (AUC 0.704).

CONCLUSION

The use of the above protocol derived from this study would reduce unnecessary CTCAPs by 37.5-40% overall. Patients who do not fulfil at least one of the above said criteria on the first assessment should not have a CTCAP initially. This protocol reduces the financial and time costs from unnecessary CTCAPs as well as reduces patient exposure to radiation and contrast.

A Retrospective Review of the Management of Lung Cancer Patients Referred into the Regional Neuro-Oncology Pathway in Merseyside, United Kingdom

AIMS

Brain metastases (BMs) are common in lung cancer and carry adverse prognostic significance. Such occurrences should be reviewed through a regional specialist neuro-oncology MDT. Our aim is to highlight which aspects of the pathway could be contributing to delays in the treatment of lung cancer patients with BMs.

METHOD

All lung cancer patients discussed at the Neuro-Oncology MDT in 2020 were identified. Details of the patient journey through the pathway from diagnosis to death were obtained from the Orion System, regional PACS system, regional neuro-oncology MDT notes and electronic case notes from Clatterbridge.

RESULTS

Full datasets were available for 100 patients discussed at the Neuro-Oncology MDT. 49 of these were patients presenting with BMs and lung cancer synchronously. Only 5 out of 13 (38%) of synchronous patients recommended for SRS received this treatment. 7 of 13 patients received a suboptimal treatment (best supportive care or whole-brain radiotherapy). Length of time from neuro-oncology MDT discussion to receiving SRS in the synchronous cohort was 47 versus 20.3 days in the asynchronous group. A review of all 13 cases found that 4 of the 7 cases of CNS-specific deterioration were potentially preventable. Further analysis of these cases revealed common themes of lengthy delays in histological sampling (9), delayed referral or discussion in the appropriate MDT (8) and not jointly referring to neuro-oncology and respiratory oncology (7).

CONCLUSION

Lung cancer patients with synchronous BMs receive SRS after full staging and biopsy. There is potential evidence of suboptimal outcomes due to inflexible MDT systems and delays for histology.

The Outcomes Measured and Reported in Meningioma Clinical Effectiveness Trials Are Heterogeneous and Preclude Comparative Analysis of Results: A Systematic Review

AIMS

Meningioma clinical trials have assessed interventions including surgery, radiotherapy, and pharmacotherapy, but heterogeneity of outcome measurement and reporting often precludes comparative analysis of trial results. This systematic review aimed to summarise the outcomes measured and reported in such trials.

METHOD

Systematic literature and trial registry searches were performed to identify published and ongoing intracranial meningioma clinical effectiveness trials. Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Deduplication, grouping, and classification of verbatim outcomes was performed to identify unique outcomes reported in the literature.

RESULTS

Thirty published articles and 18 ongoing studies were included, describing 47 unique studies: phase II n=33, phase III n=14. Common interventions included: surgery n=13, radiotherapy n=8, and pharmacotherapy n=20. 660 verbatim outcomes were reported, of which 85 were defined. Following deduplication, 416 unique verbatim outcomes remained and were grouped into 119 unique ‘non-verbatim’ outcomes. Those reported most frequently included: blood loss n=15, need for blood transfusion n=12, radiographic response to treatment n=19, eye toxicity after radiotherapy, gastrointestinal toxicity from pharmacotherapy n=40, haematological toxicity from pharmacotherapy n=31, metabolic and nutrition toxicity from pharmacotherapy n=42, progression-free survival n=46, and overall survival n=37.

CONCLUSION

Outcome measurement and reporting across meningioma clinical trials is heterogeneous and may preclude comparative analysis of trial results. The unique outcomes identified from this systematic literature review will be prioritised through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a Core Outcome Set (COS) for use in future meningioma clinical trials.

The Impact of Molecular Analysis on Patient Waiting Time: A Neurosurgical Audit

AIMS

The 2021 WHO classification includes molecular characterizations to a much greater degree. Molecular markers play an important role in deciding treatment choice and predicting prognosis. Molecular markers are often performed in separate laboratories. This has led to concerns about the amount of time taken to get further molecular markers and the delay in diagnosis. Therefore our aim was to determine the waiting time for molecular markers to be returned from the lab following surgery.

METHOD

We retrospectively collected data for patients who had molecular analysis conducted in 2020 for gliomas at The Walton Centre, Liverpool. Descriptive statistics were conducted using SPSS V27.0.

RESULTS

182 patients were included. 130 patients waited <4 weeks, 46 patients >4 weeks, and 6 patients >8 weeks for molecular marker results. The median waiting time was 21 days (range: 11-219, IQR: 17.00-31.00). For patients who waited >4 weeks and >8 weeks, there were 7 WHO Grade I, 7 Grade II, 2 Grade III, and 26 Grade IV tumours. The median time taken between surgery and treatment to begin was 15 working days (range: 7-86, IQR: 12.00- 25.00). M-array took the longest time to return with a median of 63.5 days (range: 48-93, IQR: 60.00-80.00). Following which was NGS results which took a median of 32 days (range: 21-219, IQR: 27.00-40.00)

CONCLUSION

Most patients received their results in less than 4 weeks, however nearly a third had a waiting time of greater than 4 weeks. Reasons for delays need to be explored further to allow for quicker intervention from the MDT.

Gliocova: Predictors of Post-Operative Complications, 30 Day Mortality and Readmission After First Surgical Intervention in Brain Tumour Patients in England Between 2013-2018

AIMS

The Gliocova dataset uses linked English national cancer data on all 51,775 adult primary brain tumour patients diagnosed between 2013-2018. Here we investigate patient safety and post-operative complications after first surgical intervention.

METHOD

We identified patients undergoing first surgical intervention (surgical debulking or biopsy) and used a modified Delphi approach to identify diagnosis codes indicating potential post-surgical complications. We calculated Elixhauer Comorbidity Index (ECI) weights based on our data and developed regression models to link patient characteristics and ECI with 30-day mortality, readmission and chance of complication.

RESULTS

29,258 out of 51,775 patients underwent a surgical intervention (28,173 surgical debulking; and 1,207 biopsy). 11,959 (40.9\%) patients had at least one comorbidity during first intervention admission. In hospital mortality was 0.99\% (N = 289), 30-day mortality was 2.3\% (N = 677) and 30-day readmission was 12.7\% (N = 3,725). 13,137 patients (44.9\%) had at least one complication code from our defined list, either during their first surgical intervention or during a 30-day readmission. Predictors of 30-day mortality, readmission, and risk of complications included age, ECI score, number of complications, type of intervention (biopsy vs surgical debulking), income quintile, and tumour type (i.e., Glioblastoma versus other types of brain tumours).

CONCLUSION

To our knowledge this is the first study in England to assess post-surgical complications in a large brain tumour patient cohort. Our further work will focus on variation in outcomes between different centres/ centre volumes/ regions and the cost of complications. More information: https://blogs.imperial.ac.uk/gliocova/about-gliocova/.

IDHwt Glioblastomas Show Opposing Resistance Mechanisms Across Patients in Response to Standard Treatment

AIMS

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. Despite aggressive treatment, a resistant tumour recurs in practically all patients. We therefore aimed to better understand the mechanisms driving this treatment resistance through investigating changes in gene expression across pairs of primary and recurrent GBM tumours.

METHOD

We generated or acquired bulk tumour RNA sequencing data for primary and first recurrent tumours from 107 patients who received standard treatment. Differential expression analysis between primary and recurrent samples found that the most dysregulated genes were involved in neurodevelopment and neurodifferentiation. We therefore used a publicly available ChIP-seq database to identify DNA binding factors for which binding sites are enriched in the promotors of genes with the largest expression changes from primary to recurrent.

RESULTS

Jumonji and AT-Rich Interacting Domain 2 (JARID2) was the most strongly enriched for binding to promotors of dysregulated genes. 65 patients showed an up-regulation and 42 showed a down-regulation of genes bound by this protein. The same set of JARID2 bound genes were found to be dysregulated in each direction, and correlated with the largest source of variation between samples in their response to treatment. Further enrichment analyses indicated that ‘Up’ responders may resist treatment through reduced proliferation and increased interaction with the tumour microenvironment, whereas ‘Down’ responders instead rely on a shift to mesenchymal cell states.

CONCLUSION

These results indicate that GBM tumours can be split into two subtypes that transcriptionally reprogramme in different directions through treatment and may benefit from different treatment approaches.

Management of Low-Grade Gliomas – Extent of Resection Matters But Not All Tumours Are Amenable to Surgery

AIMS

To present and review our experience in the management of low-grade gliomas.

METHOD

Retrospective case note review of all patients with WHO grade 2 glioma from 2011 to 2018 (based on WHO criteria at time of diagnosis). Data collected on demographics, presentation, location, initial management, histology, treatment, progression free (PFS) and overall survival (OS).

RESULTS

130 eligible patients. Median follow 4.6 years (up to 10.5). Median age 40 years (range: 18-83). There were 70 (53.8%) astrocytomas, 44 (33.8%) oligodenrogliomas, 16 (12.3%) oligoastrocytomas. 66%(n=86) presented with seizures, 10.7%(n=14) with sensory symptoms, 8.5%(n=11) with speech disturbance, 5.3%(n=4) with motor symptoms and 12.3%(n=16) were identified incidentally. 50.1%(n=65) were frontal, 27.7%(n=36) temporal and 9.2%(n=12) parietal. 1st line treatment was resection in 70.7%(n=92), biopsy in 23.8%(n=31) and observation in 4.6%(n=6). 15.4%(n=20) received adjuvant radiotherapy alone and 6.1%(n=8) received adjuvant radiotherapy followed by chemotherapy . At first recurrence, 31.6%(n=12) received further surgery and 95%(n=38) received radiotherapy and/or chemotherapy . Median PFS from 1st line treatment 66, 44 and 33 months for gross total resection (GRT), subtotal resection (STR), and biopsy respectively. Overall survival was 95.1%, 79.3% and 69.% for GTR, STR and biopsy respectively.

CONCLUSION

Management of low-grade gliomas remains challenging. Extent of resection impacts prognosis but not all patients have gliomas amenable to surgery. The effects of chemoradiotherapy will be presented in future meetings as this is an ongoing project.

Chronic CSF leak from lumbar-peritoneal shunt tract: A case report

Background

We describe a case of long-standing intracranial hypotension caused by an iatrogenic arachnoid diverticulum. This case illustrates two learning points. First, excessive CSF absorption may occur through an acquired arachnoid-epidural venous plexus at a dural defect. Second, a long-standing CSF leak may benefit from definitive surgical repair in the first instance.

Case Description

A 55-year-old female, with known idiopathic intracranial hypertension, presented with disabling chronic low-pressure symptoms after having a lumboperitoneal shunt removed 5 years previously. MRI scan revealed a Chiari I malformation (CMI) and a small dural interruption at the L3/4 space. CT myelography confirmed the abnormality. Intraoperatively, a dural defect and arachnoid bleb with an overlying attachment of adipose tissue and a vessel were found. Postoperatively, the patient has marked resolution of her headaches and dizziness and is mobilizing independently.

Conclusion

Excessive CSF absorption appears to have occurred through an acquired arachnoid-epidural venous plexus. A high index of suspicion for intracranial hypotension is required in patients with low pressure symptoms and a CMI.

Assessment of patients with a Chiari malformation type I

Introduction

The prevalence of Chiari malformation type I (CM-I) has been estimated as up to 1% of the general population. The majority of patients are asymptomatic and usually do not need treatment. Symptomatic patients, and some asymptomatic patients with associated conditions, may benefit from further assessment and treatment.

Research question

The aim of this review was to describe the clinical and radiological assessment of patients presenting with a CM-I.

Material and methods

A literature search was performed using the PubMed and Embase databases focused on clinical assessment and imaging techniques used to diagnose CM-I.

Results

Following a complete clinical evaluation in patients with symptomatic CM-I and/or radiologically significant CM-I (tonsillar impaction, resulting tonsillar asymmetry and loss of CSF spaces), MRI of the brain and whole spine enables an assessment of the CM-I and potential associated or causative conditions. These include hydrocephalus, syringomyelia, spinal dysraphism, and tethered cord. Flow and Cine MRI can provide information on CSF dynamics at the craniocervical junction, and help in surgical decision-making. Hypermobility or instability at the upper cervical and craniocervical junction is less common and can be measured with CT imaging and flexion/extension or upright MRI.

Discussion and conclusion

The majority of CM-I detected are incidental findings on MRI imaging of brain or spine, and do not require intervention. Once a radiological diagnosis and concern has been raised, clinical assessment by an appropriate specialist is required. A MRI brain and cervical spine is indicated in all radiologically labelled CM-I. In symptomatic patients or cases of radiologically significant CM-I, MRI of the brain and entire spine is indicated. Further investigations should be tailored to individuals’ needs.

•

A CM-I assessment should include a history and examination and a referral to a specialist.

•

MRI of the brain and spine enables an assessment of the CM-I and potential associated conditions.

•

Flow and Cine MRI can help in surgical decision-making.

Characteristics of glioblastoma long-term survivors

Aims

Glioblastoma (GBM) is the commonest and most aggressive primary malignant brain tumour in adults. A small number of patients survive for >5 years and are referred to as long-term survivors (LTS). This study aimed to quantify and characterise GBM LTS in a single large UK centre.

Method

A retrospective observational cohort study was performed. Patients diagnosed with GBM in a single UK centre between 2000–2011 (inclusive) who survived >5 years from diagnosis were included. Histopathological samples were re-examined as per the WHO 2016 classification criteria and tested for molecular biomarkers including MGMT promoter methylation, IDH1/2 mutations, 1p19q codeletion and ATRX. Demographic, imaging, treatment and outcome data were collected.

Results

1130 patients diagnosed with GBM were identified, 30 of whom survived for >5 years. Twenty-three were re-confirmed as GBM histologically and seven were reclassified as anaplastic oligodendroglioma or anaplastic astroctyoma. Median overall survival for this cohort was 6.2 years. We report a 2% 5-year survival, and a 0.7% 7-year survival. LTS-associated factors were younger age (<65 years old), frontal unilateral tumours, maximal management (surgery and chemoradiotherapy), good post-operative performance status (WHO <2), MGMT promoter methylation and IDH1/2 mutation.

Conclusion

A small subset of GBM patients survive for >5 years. Most still succumb to the disease, implying 5-year survival is not indicative of a cure. On applying current molecular markers, a quarter of previously diagnosed glioblastoma in this LTS population were revised to be WHO grade III gliomas.

Tumour Treating Fields in Glioblastoma: Is the treatment tolerable, effective, and practical in UK Patients?

Aims

Tumour Treating Fields (TTF) in combination with standard therapy, prolongs survival in patients with Glioblastoma (GBM). The aim of the current study was to assess the feasibility of integrating TTF into a standard UK neuro-oncology service with a focus on patient tolerability, compliance, and treatment delivery.

Method

A prospective study was performed of UK patients with IDH 1 Wild Type, MGMT Unmethylated GBM treated with TTF, in conjunction with conventional therapy. Patient compliance data, device-specific tolerability questions, and an evaluation of disease progression and survival were collected. Monthly quality of life (QoL) questionnaires (EORTC QLQ-C30 with BN-20) examined the trend of global health, psychosocial function and symptom progression.

Results

Nine patients were enrolled with a median age of 47 (7 males; 2 females). Overall, compliance with TTF was 89% (range 16% - 97%). Only one patient failed to comply with treatment. Patients tolerated the device with minimal side effects. Eight patients described mild to moderate skin irritation, whilst all patients were keen to recommend the device to other patients (100%). Most patients found the weight and size of the device to be its biggest drawback (72%). Progression-free survival was 5.5 months and median overall survival 14.9 months.

Conclusion

TTF was well tolerated amongst a small cohort of UK patients, who were able to comply with treatment without any significant complication. QoL questionnaires showed no sustained deterioration in global health, physical and emotional function until the final months of life, when disease burden was greatest.

Cranial Meningiomas Requiring Cranioplasty

Aims

Bone infiltration in association with intracranial meningioma (4.5% of cases) and primary intraosseous meningioma (2%) are rare. Management can be challenging, as cranial vault reconstruction may be required. This study aimed to examine the surgical techniques used and outcomes in this patient population.

Method

A single-centre, retrospective cohort study was conducted between January 2010 and September 2020. All adult patients who required cranial reconstruction due to bone involvement of their meningioma were included. Patient demographics, tumour characteristics, operative details, complications, and outcomes were examined. Statistical analyses were performed using SPSS v24.0.

Results

There were 30 patients (17 female; 56.7%), median age 54 yrs (range 28-86 yrs), of whom 25 (83.3%) had bone infiltration, and 5 (16.7%) had primary intraosseous meningioma. Only 10 patients had a Simpson I or II resection. Twenty-eight had 'on-table' primary cranioplasties. Materials used were titanium (n=13; 43.3%), acrylic (n=10; 33.3%), PMMA (n=5; 16.7%), and hydroxyapatite (n=2; 6.7%). There were 9 (mostly minor) surgical complications and only one wound infection. Twelve patients had WHO grade II tumours, and 14 required radiotherapy. Ten patients (33.3%) had re-operation for recurrent tumour, with a median time to progression of 41 months. At 6 months, 24 patients had a performance score less than 2.

Conclusion

On-table cranioplasty provides a lower risk surgical option for patients with high risk meningiomas.

OS14.6.A GlioCova: Defining patient safety events for brain tumour patients undergoing neurosurgery

BACKGROUND

Surgery is associated with a risk of adverse events (e.g. venous thrombosis). These have been used to define the OECD Patient Safety Event (PSE) indicators (41 diagnostic codes), but not in the brain tumour population. The GlioCova project uses English linked national cancer data on all 51,775 adult primary brain tumour patients (2013–2018).

MATERIAL AND METHODS

We identified all glioblastoma patients having surgery for their tumour and noted the 100 most common ICD-10 diagnostic codes within 30 days of surgery, excluding previous medical conditions, brain tumour diagnosis codes and OECD-defined codes. Potential post-surgical complications were reviewed by a group of experienced clinicians. We reviewed these “novel PSE codes” in all brain tumour patients re-admitted after surgery. We looked at the co-occurrence between our novel and OECD codes and combined them to form the final PSE list.Patients readmitted within 30 days were divided into those without codes (“PSE-free”), and those with at least one PSE code during admission or readmission. We examined age, length of stay, in-hospital and 30-day mortality and assessed statistical significance using Welch’s t-test and a two sample Z-test for proportions.

RESULTS

29,135 patients underwent neurosurgery, of whom 8,361 (28.7%) were readmitted within 30 days. We identified 32 novel PSE codes. 1,319 (16%) patients had an OECD code, 5,524 (66%) had a novel code, and 2,098 (25%) patients were PSE-free. 83% of patients who had an OECD PSE code also had a novel code. Patients in the PSE group were older (median age = 60 years) than the PSE-free group (57 years). Length of stay was longer in patients who had a PSE after surgery (median = 7 days) and after readmission (5 days) compared with PSE-free after surgery (4 days), at readmission (0 days). More patients died in hospital after readmission in the PSE group (4.7%) compared with no-PSE (2.7%). 30-day mortality after surgery was similar in both groups (2.5% PSE-free, 3.1% PSE group). All differences were highly statistically significant (p<0.0001).

CONCLUSION

We identified 32 novel patient safety event codes following surgery in the brain tumour population. Patients with these diagnostic codes had an elevated LOS and in-hospital death rate. Using brain tumour specific PSE codes captures many more events than the existing list of OECD codes.

Posterior fossa decompression with duraplasty in Chiari malformation type 1: a systematic review and meta-analysis

BACKGROUND

Surgery for symptomatic Chiari type I malformation (CM-I) patients include posterior fossa decompression (PFD) involving craniectomy with or without dural opening, and posterior fossa decompression with duraplasty (PFDD). This review aims to examine the evidence to aid surgical decision-making.

METHODS

A medical database search was expanded to include article references to identify all relevant published case series. Animal studies, editorials, letters, and review articles were excluded. A systemic review and meta-analysis were performed to assess clinical and radiological improvement, complications, and reoperation rates.

RESULTS

Seventeen articles, containing data on 3618 paediatric and adult participants, met the inclusion criteria. In the group, 5 papers included patients that had the dura left open. PFDD is associated with better clinical outcomes (RR 1.24, 95% CI, 1.07 to 1.44; P = 0.004), but has a higher complication rate (RR 4.51, 95% CI, 2.01 to 10.11; P = 0.0003). In adults, clinical outcomes differences did not reach statistical significance (P = 0.07) but re-operation rates were higher with PFD (RR 0.17, 95% CI 0.03 to 0.86; P = 0.03), whilst in children re-operation rates were no different (RR 0.97, 95% CI 0.41 to 2.30; P = 0.94). Patients with a syrinx did better with PFDD (P = 0.02). No significant differences were observed concerning radiological improvement.

CONCLUSIONS

In the absence of hydrocephalus and craniocervical region instability, PFDD provides better clinical outcomes but with higher risk. The use of PFD may be justified in some cases in children, and in the absence of a syrinx. To help with future outcome assessments in patients with a CM-I, standardization of clinical and radiological grading systems are required.

TRIAL REGISTRATION

not required.

Professional Profiles, Technical Preferences, Surgical Opinions, and Management of Clinical Scenarios from a Panel of 63 International Experts in the Field of Chiari I Malformation

BACKGROUND

Chiari I Malformation (CMI) and the topics concerning it have been the subject of numerous discussions and polarizing controversies over the course of the past 20 years.

METHODS

The opinions of 63 recognized international Neurosurgical CMI experts from 4 continents, with a collective surgical experience of more than 15,000 CMI cases, were gathered through a detailed questionnaire, divided in two parts: diagnostic and therapeutic. The therapeutic part was organized into four sections: Professional Profile, Technical Preferences, Surgical Opinions, and Clinical Scenarios.

RESULTS

The data reflected a wide spectrum of opinions, approaches, and expertise. The second part of the questionnaire dealt with the surgical aspects of CMI care and painted a more complex picture: • 81% of the surgeons preferred the Intradural technique. • 88% of the experts agreed that CMI surgery is not indicated for minimal non-debilitating symptoms alone, or as prophylaxis. • In the face of given clinical scenarios, a wide spectrum of therapeutic approaches was chosen by the whole group, but the 4 Surgeons with the largest case series expressed the same opinion. • Eight out of 63 Surgeons had a surgical experience above 600 cases, were responsible for more than half of the total 15,000 declared CMI cases, and shared a similar profile in terms of technical surgical choices, therapeutic opinions, and low complication rate, with a marked preference for Intradural techniques and tonsillar manipulation. • Once large individual case series were accumulated, we did not see any differences in the opinions and preferences between Adult and Pediatric Neurosurgeons.

CONCLUSION

Surgeons who have focused on CMI have been able to accumulate large surgical series, have chosen in their practices the more aggressive (and intrinsically more effective) CMI surgical techniques, and have achieved a low complication rate which compares favorably with that one of the extradural techniques.

RARE-50. PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA – OUTCOMES IN THE ‘HAEMATOLOGY ERA’

BACKGROUND

Primary CNS lymphoma (PCNSL) requires a biopsy for diagnosis. Administration of corticosteroids can lead to inconclusive results and delay diagnosis. The aim of this study was to compare outcomes of patients treated under haematology compared to radiation oncologists.

METHODS

Retrospective case review of patients treated under radiation oncology (2006–2010) and haematology (2011–2016).

RESULTS

121 cases were identified (median age 63 years; range 19–84). Median WHO performance status (PS) was 1. Fourteen patients (11.6%) required repeat biopsy. 10 patients were managed palliatively due to poor PS. 67 cases were managed under haematology. Median symptom duration was 28 days (range 2–540). Median time from MRI to diagnosis was 18 days (range 6–232). 66 patients received chemotherapy, 1 received radiotherapy. Median overall survival (OS) was 8 months (95%CI:0.7–15.3), 5-year OS was 22.4%. 44 cases were managed under radiation oncology. Median symptom duration was 28 days (range 2–365). Median time from MRI to diagnosis was 16 days (range 6–309). 34 patients received radiotherapy first-line, 10 received chemotherapy. Median OS was 7 months (95%CI:0–21.5), 5-year OS was 15.9%. Multivariate analysis demonstrated PS (HR 2.02 (95%CI: 1.08–3.76)) and symptom duration (HR 0.63 (95%CI: 0.41–0.96)) to be significant prognostic indicators for OS.

CONCLUSION

The outcomes from the ‘haematology era’ are similar to those achieved by radiation oncologists. Delay in diagnosis leads to worse outcomes and highlights the ongoing need to streamline the patient pathway to improve outcomes.

Primary Central Nervous System Lymphoma – Management and Outcome in the ‘haematology era’

Introduction

Primary CNS lymphoma (PCNSL) requires a biopsy for diagnosis but can be inconclusive when steroids are administered. Without treatment median survival is 1.5–3.3 months, improving to 10–20 months with oncological treatment. This study aimed to compare outcomes of PCNSL treated under haematology to those of clinical oncologists.

Methods

Retrospective casenote review of patients with PCNSL treated under oncologists (2006–2010) and haematologists (2011–2016).

Results

121 cases were identified (median age 63 years; range 19–84). Median WHO performance status (PS) was 1. 11.6% required repeat biopsy.

10 patients were managed palliatively due to poor PS.

67 cases were managed under haematology. Median symptom duration was 28 days (range 2–540). Median time from MRI to diagnosis was 18 days (range 6–232). 66 patients received chemotherapy, 1 received radiotherapy. Median overall survival (OS) was 8 months (95%CI: 0.7–15.3), 5-year OS was 22.4%.

44 cases were managed under oncology. Median symptom duration was 28 days (range 2–365). Median time from MRI to diagnosis was 16 days (range 6–309). 34 patients received radiotherapy first-line, 10 received chemotherapy. Median OS was 7 months (95%CI: 0–21.5), 5-year OS was 15.9%.

Multivariate analysis demonstrated PS (HR 2.02 (95%CI: 1.08–3.76)) and symptom duration (HR 0.63 (95%CI: 0.41–0.96)) to be significant prognostic indicators for OS.

Discussion

PCNSL carries poor prognosis and outcomes from the ‘haematology era’ are similar to those achieved by clinical oncologists. Delay in diagnosis leads to worse outcomes and highlights the ongoing need to streamline current clinical services to improve outcomes.

Management and outcomes of meningiomas secondary to childhood and adolescent radiation treatment

Background

With the increased rate of childhood cancer survivors, a marked rise in the incidence of secondary intracranial meningiomas has been established.

Objective

Determine the outcomes of patients diagnosed with radiation-induced meningiomas (RIM).

Methods

Single-centre retrospective cohort study of patients with new or recurrent RIM (2007–2018).

Results

47 patients were identified (21 females). Mean age at radiation was 15 years (SD=14) and the most common indications were leukaemia (n=8) and childhood brain tumours (n=35; medulloblastoma and pilocytic astrocytoma (n=7 each)). 93 de-novo meningiomas were identified. The median latency period between radiation and diagnosis was 28.5 years (IQR 22–37). 61% were asymptomatic whilst the remainder manifested headache (20%), focal neurological deficit (12%) and epilepsy (5%). 32 operated de-novo RIM revealed WHO grade I (n=19; 59%), WHO grade II (n=11; 34%) and 2 intraosseous meningiomas (n=2; 6%). After a median of 5 years (IQR 3–10), 9 (28%) operated RIM recurred/progressed. At recurrence, 5 were operated (3 WHO grade I, 2 WHO grade II and 1 WHO grade III), 2 patients were palliated and 2 remain under active observation. By the end of the study period, 20 patients were harbouring multiple meningiomas and 8 patients were deceased.

Conclusion

Radiation-induced meningioma should be monitored until symptomatic. Operated RIMs have a high recurrence rate. Further radiotherapy is not effective. Further clinical and genetic analyses as part of an international multi-centre collaboration are planned.

Chromatin remodelling to facilitate treatment resistance in glioblastoma

Recent findings from our group, and the wider community, show that standard treatment does not impose an apparent bottleneck on the clonal evolution of adult glioblastoma (GBM), implying a lack of direct therapeutic opportunity. This does not negate the possibility that multiple treatment-resistance mechanisms co-exist in tumours, repeated across patients, making a combination of targeted therapies a potentially effective approach. We investigated whether treatment resistance may be driven by selection of cellular properties conferred above the level of the genome. Differential expression analysis was performed on 23 pairs of primary and recurrent tumours from patients who received standard treatment and had a local recurrence treated by surgery and second line chemotherapy. This revealed a treatment-induced shift in cell states linked to normal neurodevelopment. The latter is orchestrated by cascades of transcription factors. We, therefore, applied a bespoke gene set enrichment analysis to our paired expression data to investigate whether any factors were implicated in co-regulation of the genes that were altered through therapy. This identified a specific chromatin remodelling machinery, instrumental in normal neurogenesis. We validated our results in an independent cohort of 22 paired GBM samples. Our results suggest that the chromatin remodelling machinery is responsible for determining transcriptional hierarchies in GBM, shown elsewhere to have different treatment sensitivities such that their relative abundances are altered through treatment.

Glioblastoma multiforme in patients over 65 – should we operate?

Aim

Current standard of care for glioblastoma is maximum safe resection followed by radio chemotherapy with Temozolomide. Older patients are less likely to receive the full treatment. The aim was to determine treatment and outcomes in glioblastoma patients >65 years.

Methods

Single centre retrospective study from 2001–2016. Eligible patients had: (i) diagnosis of glioblastoma (ii) undergone biopsy or resection with radiotherapy ± adjuvant chemotherapy. Age at diagnosis, type of surgery, performance status, complications, adjuvant therapy and median survival (MS) were recorded. Patients were assigned to group A (age <65), B (age 65–69 years) or C (age >/= 70 years).

Results

637 patients met the eligibility criteria and 403 had complete records for analysis. Age distribution of the cohort was 17.9 – 91.6 years.

In the group A (n=259), those who had undergone resection had significantly longer MS compared to biopsy: 17.2 vs 13.2 months (P<0.05 CI: 444.043 – 561.957). 70 patients developed complications.

In the group B (n=79), those who had undergone resection had significantly longer MS compared to biopsy: 12.3 vs 5.1 months (P<0.05 CI: 194.354 – 335.646). 17 patients developed complications.

In the group C (n=64), analysis did not show statistically significant difference (P=0.066 CI: 220.476 – 321.524). Clinically, patients who had resection had longer MS (10.5 months vs 3.5 months). Furthermore, there was no significant difference in the rate of complications between resection and biopsy (Fisher’s exact test, P=0.755).

Conclusion

i) Patients >65 should be treated as per the Stupp protocol ii) In patients >70 surgical resection should be considered.:

OS9.5 Evidence that adult glioblastoma adapts to standard therapy though chromatin remodeling

BACKGROUND

Glioblastoma (GBM) tumours recur following standard treatment in almost all cases. We use ‘omics technologies to simultaneously profile pairs of primary and matched recurrent GBM to specifically identify and characterise the cells that resisted treatment, with the aim of determining how to more effectively kill them.

MATERIAL AND METHODS

We have analysed high coverage RNAseq data from pairs of GBM tumours: primary de novo tumour and matched local recurrence from patients that underwent standard therapy. Our original cohort constituted 23 pairs and our validation cohort was an additional 22 pairs. We also cultured two plates of spheroids directly from a patient’s GBM, treating one with radiation and temozolomide. We monitored growth and captured and sequenced RNA from single cells at two time-points: one week post-treatment when the deviation between untreated and treated spheroid growth curves was most pronounced; and three weeks post-treatment when the growth rate of treated spheroids had recovered. We investigated differential gene expression between primary and recurrent pairs, and single cells pre- and post-treatment, and performed a bespoke per patient gene set enrichment analysis.

RESULTS

Differential gene expression analysis in 23 tumour pairs indicated a treatment-induced shift in cell states linked to normal neurogenesis and prompted us to develop a novel gene set enrichment analysis approach to identify gene regulatory factors that may orchestrate such a shift. This revealed the significant and universal dysregulation of genes, through therapy, that are targeted by a specific chromatin remodeling machinery. This finding was validated in an independent cohort of 22 further GBM pairs. To understand the therapeutic potential of this finding we must determine whether genes are dysregulated through therapy owing to a) their fixed expression in inherently treatment resistance cells in the primary tumour which get selected during therapy to increase the signal of that profile, or b) changes in expression during the process of cells acquiring treatment resistance. To inspect this, we analysed single cell gene expression data from GBM spheroids pre- and post-treatment. We found that there was significant dysregulation of the genes associated with the chromatin remodeling complex but only at the three-week post-treatment time-point.

CONCLUSION

Our results indicate that GBM cells are being transcriptionally reprogrammed in response to treatment; the mechanism of which may represent a therapeutic opportunity.

The influence of concomitant syringomyelia on patient reported outcome following hind brain decompression

Objectives: To evaluate the impact of concomitant syringomyelia and self-reported complications on patient reported outcome measures in patients undergoing hindbrain decompression for a Chiari 1 malformation.Methods: Prospective data collection of 95 patients who underwent Foramen magnum decompression between March 2011 and March 2015. Outcome evaluation was performed using the Core Outcome Measure Index questionnaire for neck (COMI-neck) and Gestalt impression (to assess improvement of headaches). Patients were split into two cohorts, those with and those without syringomyelia. Both cohorts were compared in all domains of the COMI neck questionnaires, headache, and complications. Non-parametric data were analysed with Wilcoxon signed rank, Mann-Whitney U and Fisher exact tests. Parametric data were analysed with Student T-test. SPSS Software was used for analysis.Results: 79 patients returned 1 year follow-up COMI-neck questionnaires. Thirty three had concomitant syringomyelia and 46 had no syringomyelia present. There was no statistically significant difference in patient reported outcomes (COMI-neck index median 4.5 +/- 3.3 vs 4.2+/-3.2; p = .376) between the syrinx and non-syrinx cohorts. However postoperative neck pain (median 4 +/- 3.35 vs 1 +/- 3.17; p 0.041) and arm/shoulder pain scores (2 +/- 3.38 vs. 0+/- 2.628; p 0.049) were significantly lower in the non-syrinx cohort. In both cohorts 57% patients had an improvement in headache. 92% patients were 'satisfied' with treatment and 63% stated that the operation 'helped'. 54% patients in the syrinx and 59% in the non-syrinx cohort self-reported complications. There was no statistical difference in outcomes of the patients with and without self-reported complications (p = .121).Conclusions: This study demonstrates that the clinical effectiveness of FMD is lower and reported complications are higher when evaluated by patient reported outcome measures as opposed to surgeon reported complications. Patients with and without concomitant syringomyelia showed equal overall outcomes, although neck and arm pain was worse in syrinx patients.

Chiari I Malformation: Opinions on Diagnostic Trends and Controversies from a Panel of 63 International Experts

BACKGROUND

Chiari I malformation (CMI) and the topics concerning it have been the subject of numerous discussions and polarizing controversies over the course of the last 20 years.

METHODS

The opinions of 63 recognized international CMI experts from 4 continents, with a collective surgical experience of >15,000 CMI cases, were gathered through a detailed questionnaire.

RESULTS

Three facts emerged from the analysis of the results: 1) Most of the replies showed a high level of consensus on most CMI-related topics. 2) Several topics, which had been considered controversial as recently as 10 years ago, are now more widely accepted. 3) The so-called 5-mm rule was rejected by 88.5% of the CMI experts who responded to the questionnaire.

CONCLUSIONS

Sixty three recognized international CMI experts from 4 continents, with a collective surgical experience of >15,000 CMI cases were polled about a number of CMI topics. The results showed a high level of consensus, as well as a paradigm shift.

The utility of surgery in butterfly glioblastoma: A case-control study

e13529

Background: Glioblastoma is the most common primary brain tumour and may rarely infiltrate the corpus callosum. Such ‘butterfly’ glioblastomas (BGBM) are believed to confer a poorer prognosis than their non-callosal counterparts. We aimed to determine the impact of surgery on overall survival (OS) and postoperative morbidity in butterfly glioblastomas. Methods: Retrospective analysis was performed on all case notes of patients histologically diagnosed with GBM from January 2011 to January 2017 at The Walton Centre NHS Foundation Trust, Liverpool. Data was collected under the following headings: demographics, tumour characteristics, surgical data, adjuvant therapy and survival data. A case-matched control group was produced according to age, sex and 1o resection. Univariate analysis was performed. Results: 632 glioblastoma patients were identified. 37 patients were diagnosed with butterfly BGBM, with a median age of 62.7 years and a gender split of 24 males (64.9%) to 13 females (35.1%). Median tumour volume was 31700mm3, with 24 (56%) tumours involving the genu and 13 (22%) the splenium of the callosum. Kaplan-Meier analysis with log-rank testing demonstrated a significant (p = 0.04) decrease in median OS in those with BGBM (100 days (95%CI 57-142)) vs controls (276 days (95%CI 224-327)). Resection of BGBMs resulted in longer median OS than biopsy alone (296 days (95%CI 229-363) vs 81 (66-96)), though this was a non-significant difference (p = 0.36). Multifocal disease occurred significantly more often in BGBM patients (p = 0.01), the exclusion of which from analysis demonstrated a significant survival benefit with resection (427 days (95%CI 207-647)) compared to biopsy (221 days (95%CI 151-291)) (p = 0.04). Postoperative complications did not occur significantly more often in BGBM resections than controls (7/36 (19.4%) vs 5/36 (13.9%) (p = 0.257)). Conclusions: Overall, butterfly glioblastomas confer a worse prognosis than those without callosal involvement. A greater prevalence of multifocal disease is seen in butterfly glioblastoma, warranting further investigation. Resection offers a significant improvement in OS in solitary butterfly glioblastomas without a significant increase in postoperative morbidity, and should therefore be considered an efficacious and safe treatment option.

Quality improvement of neuro-oncology services: integrating the routine collection of patient-reported, health-related quality-of-life measures

BACKGROUND

Brain cancer has a strong impact on health-related quality of life (HRQoL), and its evaluation in clinical practice can improve the quality of care provided. The aim of this project was to integrate routine collection of HRQoL information from patients with brain tumor or metastasis in 2 specialized United Kingdom tertiary centers, and to evaluate the implementation process.

METHODS

Since October 2016, routine collection of electronic self-reported HRQoL information has been progressively embedded in the participating centers using standard questionnaires. During the first year, the project was implemented, and the process evaluated, through regular cycles of process evaluation followed by an action plan, monitoring of questionnaire completion rates, and assessment of patient views.

RESULTS

Main challenges encountered included reluctance to change usual practice and limited resources. Key measures for success included strong leadership of senior staff, involvement of stakeholders in project design and evaluation, and continuous strategic support to professionals. Final project workflow included 6 process steps, 1 decision step, and 4 outputs. Questionnaires were mostly self-completed (75.1%), and completion took 6-9 minutes. Most patients agreed that the questionnaire items were easy to understand (97.0%), important for them (93.0%), and helped them think what they wanted to discuss in their clinical consultation (75.4%).

CONCLUSIONS

Integrating HRQoL information as a routine part of clinical assessments has the potential to enhance individually tailored patient care in our institutions. Challenges involved in innovations of this nature can be overcome through a systematic approach involving strong leadership, wide stakeholder engagement, and strategic planning.

Defining unmet clinical need across the pathway of brain tumor care: a patient and carer perspective

Objective

The aim of this study was to determine the experience of patients with brain tumors and their carers across distinct parts of their treatment pathway and identify their views on potential service gaps in need of addressing.

Methods

A structured survey was administered at patient workshops across the UK and online through a charity newsletter. Answers to closed questions were analyzed using descriptive statistics, and open questions were examined using techniques of inductive content analysis.

Results

A total of 136 survey responses were received, representing patients with a variety of diagnoses and geographical locations (30 counties). There was a wide range of opinions on the provision of current neuro-oncology services. Key themes identified included a perceived lack of information provision, a gap in postdischarge psychological and neuropsychological supports, and an unmet willingness for involvement in research.

Conclusion

This national survey enhances our knowledge of current patient and carer experience within neuro-oncology services. A number of areas of unmet clinical need are highlighted providing a basis for informing future patient-centered service improvements and research.

Combining random forest and 2D correlation analysis to identify serum spectral signatures for neuro-oncology

Fourier transform infrared (FTIR) spectroscopy has long been established as an analytical technique for the measurement of vibrational modes of molecular systems. More recently, FTIR has been used for the analysis of biofluids with the aim of becoming a tool to aid diagnosis. For the clinician, this represents a convenient, fast, non-subjective option for the study of biofluids and the diagnosis of disease states. The patient also benefits from this method, as the procedure for the collection of serum is much less invasive and stressful than traditional biopsy. This is especially true of patients in whom brain cancer is suspected. A brain biopsy is very unpleasant for the patient, potentially dangerous and can occasionally be inconclusive. We therefore present a method for the diagnosis of brain cancer from serum samples using FTIR and machine learning techniques. The scope of the study involved 433 patients from whom were collected 9 spectra each in the range 600-4000 cm(-1). To begin the development of the novel method, various pre-processing steps were investigated and ranked in terms of final accuracy of the diagnosis. Random forest machine learning was utilised as a classifier to separate patients into cancer or non-cancer categories based upon the intensities of wavenumbers present in their spectra. Generalised 2D correlational analysis was then employed to further augment the machine learning, and also to establish spectral features important for the distinction between cancer and non-cancer serum samples. Using these methods, sensitivities of up to 92.8% and specificities of up to 91.5% were possible. Furthermore, ratiometrics were also investigated in order to establish any correlations present in the dataset. We show a rapid, computationally light, accurate, statistically robust methodology for the identification of spectral features present in differing disease states. With current advances in IR technology, such as the development of rapid discrete frequency collection, this approach is of importance to enable future clinical translation and enables IR to achieve its potential.

Feature driven classification of Raman spectra for real-time spectral brain tumour diagnosis using sound

Spectroscopic diagnostics have been shown to be an effective tool for the analysis and discrimination of disease states from human tissue. Furthermore, Raman spectroscopic probes are of particular interest as they allow for in vivo spectroscopic diagnostics, for tasks such as the identification of tumour margins during surgery. In this study, we investigate a feature-driven approach to the classification of metastatic brain cancer, glioblastoma (GB) and non-cancer from tissue samples, and we provide a real-time feedback method for endoscopic diagnostics using sound. To do this, we first evaluate the sensitivity and specificity of three classifiers (SVM, KNN and LDA), when trained with both sub-band spectral features and principal components taken directly from Raman spectra. We demonstrate that the feature extraction approach provides an increase in classification accuracy of 26.25% for SVM and 25% for KNN. We then discuss the molecular assignment of the most salient sub-bands in the dataset. The most salient sub-band features are mapped to parameters of a frequency modulation (FM) synthesizer in order to generate audio clips from each tissue sample. Based on the properties of the sub-band features, the synthesizer was able to maintain similar sound timbres within the disease classes and provide different timbres between disease classes. This was reinforced via listening tests, in which participants were able to discriminate between classes with mean classification accuracy of 71.1%. Providing intuitive feedback via sound frees the surgeons' visual attention to remain on the patient, allowing for greater control over diagnostic and surgical tools during surgery, and thus promoting clinical translation of spectroscopic diagnostics.

How to analyse the spatiotemporal tumour samples needed to investigate cancer evolution: A case study using paired primary and recurrent glioblastoma

Many traits of cancer progression (e.g., development of metastases or resistance to therapy) are facilitated by tumour evolution: Darwinian selection of subclones with distinct genotypes or phenotypes that enable such progression. Characterising these subclones provide an opportunity to develop drugs to better target their specific properties but requires the accurate identification of somatic mutations shared across multiple spatiotemporal tumours from the same patient. Current best practices for calling somatic mutations are optimised for single samples, and risk being too conservative to identify shared mutations with low prevalence in some samples. We reasoned that datasets from multiple matched tumours can be used for mutual validation and thus propose an adapted two-stage approach: (1) low-stringency mutation calling to identify mutations shared across samples irrespective of the weight of evidence in a single sample; (2) high-stringency mutation calling to further characterise mutations present in a single sample. We applied our approach to three-independent cohorts of paired primary and recurrent glioblastoma tumours, two of which have previously been analysed using existing approaches, and found that it significantly increased the amount of biologically relevant shared somatic mutations identified. We also found that duplicate removal was detrimental when identifying shared somatic mutations. Our approach is also applicable when multiple datasets e.g. DNA and RNA are available for the same tumour.

T-Cell Densities in Brain Metastases Are Associated with Patient Survival Times and Diffusion Tensor MRI Changes

Brain metastases are common and are usually detected by MRI. Diffusion tensor imaging (DTI) is a derivative MRI technique that can detect disruption of white matter tracts in the brain. We have matched preoperative DTI with image-guided sampling of the brain-tumor interface in 26 patients during resection of a brain metastasis and assessed mean diffusivity and fractional anisotropy (FA). The tissue samples were analyzed for vascularity, inflammatory cell infiltration, growth pattern, and tumor expression of proteins associated with growth or local invasion such as Ki67, S100A4, and MMP2, 9, and 13. A lower FA in the peritumoral region indicated more white matter tract disruption and independently predicted longer overall survival times (HR for death = 0.21; 95% confidence interval, 0.06-0.82; P = 0.024). Of all the biological markers studied, only increased density of CD3⁺ lymphocytes in the same region correlated with decreased FA (Mann-Whitney U, P = 0.037) as well as confounding completely the effect of FA on multivariate survival analyses. We conclude that the T-cell response to brain metastases is not a surrogate of local tumor invasion, primary cancer type, or aggressive phenotype and is associated with patient survival time regardless of these biological factors. Furthermore, it can be assayed by DTI, potentially offering a quick, noninvasive, clinically available method to detect an active immune microenvironment and, in principle, to measure susceptibility to immunotherapy.Significance: These findings show that white matter tract integrity is degraded in areas where T-cell infiltration is highest, providing a noninvasive method to identify immunologically active microenvironments in secondary brain tumors. Cancer Res; 78(3); 610-6. ©2017 AACR.