tbuckley/cabot-search huggingface dataset:
AUDIT TO EVALUATE CURRENT RADIOTHERAPY (RT) PLANNING PATHWAY: COULD CURRENT PRACTICE BE IMPROVED BY THE TIMING OF MAGNETIC RESONANCE IMAGING (MRI)?
Authors: Ms Carol Thurgood
Journal: Neuro-Oncology (2024)

Abstract AIMS To evaluate the current guidance for glioblastoma (GBM) and primary brain radiotherapy (RT) planning. Current practice in this centre utilises pre and post-surgical MRI for RT target delineation. This study aims to explore the practicality and impact of scheduling an RT planning-speciﬁc MRI no more than 2 weeks before RT treatment start date (TSD). Time from surgery to RT TSD will also be explored. METHOD Fifty GBM patients, treated between August 2022 and October 2023, were audited retrospectively. Included patients were treated with radical intent and must have had surgery or biopsy. Age, gender or performance status (PS) were excluded from audit criteria. Age of MRI used for RT planning and surgery to TSD was noted. RESULTS Early results showed that the average age of MRI used for RT planning was 7 weeks old and Surgery to TSD was 7 weeks. A new pathway was introduced after 37 patients as these results were considered unacceptable. The new pathway included 1 reserved MRI appointment and one reserved RT Mask/CT appointment per week. 13 patients’ pathways were audited after introduction of the new pathway. The results showed that the average age of MRI used for RT planning was 2 weeks old and surgery to TSD was 6 weeks. CONCLUSION Limitations of the audit included disparity between number of patients before and after introduction of the new pathway. This was because of the time limitation for completion of the study. Improvement was seen in timing of MRI to TSD. However, the small improvement in timing of surgery to TSD was impacted by human factors rather than organisational inﬂuence, for example, surgical deconditioning, delays for wound healing and patient choice. This study has shown that the ideal timing of MRI can be achieved.
RE-VISITING BIOPSIES FOR SUSPECTED CNS LYMPHOMAS: TO BIOPSY OR NOT TO BIOPSY?
Authors: Mr Mesi Mathew, Mr Chittoor Rajaraman, Mr Shailendra Achawal, Mr Adam Razak, Mr Gerry O’Reilly
Journal: Neuro-Oncology (2024)

Abstract AIMS It is a common practice to get a histological diagnosis before treatment of suspected CNS (central nervous system) lymphoma. Should CNS lesions be routinely biopsied in patients with background systemic lymphoma? METHOD A 10-year retrospective review of biopsy-proven CNS lymphoma was conducted. Data was analyzed using SPSS for Windows, version 25 (SPSS, Inc., Chicago, Illinois, USA), and a p-value &amp;lt; 0.05 was considered signiﬁcant for the appropriate test statistic. RESULTS Patients with background systemic lymphoma whose brain MRI appearances were in favour of lymphoma after MDT discussion all had histologically-proven lymphoma after brain biopsy. Pre-biopsy MDT diagnosis was congruent with post-biopsy histology in 87.6% of cranial lesions (p-value 0.003) and 40% of spinal lymphomas (p-value 0.002). Secondary CNS lymphoma was seen in 21.2%. Stereotactic brain biopsy was the most common biopsy technique for cranial lesions (79.8%). Histology was Diffuse B Cell Lymphoma in 93% of cases. The mean Ki67 percentage for cranial lymphomas was higher than that of spine (p-value 0.028) The complication rate for cranial biopsy was 8.9%. Transient motor deﬁcits (4.4%) and post-operative haematoma (2.2%) were the most common. The 24-hour post-brain biopsy mortality rate was 1.1%, while overall 30-day post-op mortality rate was 4.4%. The mean percentage of Ki67 was higher among patients who had complications (p-value 0.001). CONCLUSION In a setting of properly constituted neurooncology MDT, a sub-set of patients with suspected brain lymphoma and background systemic lymphoma might not require brain biopsy. KEY WORDS Lymphoma, Brain, Spine, Biopsy, Complication
PROTAC’ING CENTROSOME AMPLIﬁCATION PROTEINS: TARGETED PROTEIN DEGRADATION AS A NOVEL THERAPEUTIC STRATEGY IN GLIOBLASTOMA
Authors: Dr Amanda Thomaz, Dr Andrew Fielding
Journal: Neuro-Oncology (2024)

Abstract AIMS Glioblastomas (GBMs) are the most common and aggressive brain tumours, notoriously diﬃcult to treat with universal treatment resistance. A key feature of cancer cells is centrosome ampliﬁcation (CA), leading to chromosomal instability and worse patient outcomes, including metastasis development and treatment resistance. In this work, I identiﬁed CA proteins overexpressed in GBM and aimed to investigate how the targeted degradation of proteins associated with centrosome ampliﬁcation can inﬂuence the growth and survival of GBM cells. METHOD Based on well-established literature data concerning CA-related genes, I evaluated the expression level of these targets in different types of samples from the Tumour Cancer Genome Atlas dataset of GBM patient samples. Following the identiﬁcation of CA targets differentially overexpressed, to test the hypothesis that CA proteins could be involved in the survival of GBM cells and be potential therapeutic targets, I used a novel drug modality, named Proteolysis Targeting Chimeras (PROTACs) to degrade two CA proteins. PROTACs can quickly destroy speciﬁc proteins, potentially overcoming resistance to treatment. Target degradation was conﬁrmed via immunoblotting and cell viability and cell cycle analysis were performed to evaluate the impact on GBM cells. RESULTS Both primary and recurrent GBM samples display high levels of CA gene signature when compared to noncancerous samples, and some CA genes are particularly upregulated in recurrent samples. The PROTACs were effective in degrading both CA targets in GBM cells, leading to a signiﬁcant decrease in cell viability and G2 cell cycle arrest. CONCLUSION This study presents initial evidence that CA protein degradation could be a promising avenue for GBM research and therapy. Further research is needed to fully assess the translational potential of PROTACs in GBM treatment.
MENINGIOMA SIZE IS POSITIVELY CORRELATED WITH TUMOR WHO GRADE
Authors: Dr Said Kocyigit, Dr Omer Orhun, Dr Ahmet Harun Yasar, Dr Ayca Ersen Danyeli, Prof Alp Dincer, Prof Necmettin Pamir, Prof Koray Ozduman
Journal: Neuro-Oncology (2024)

Abstract AIMS It is well established that the surgical outcome is poorer in larger meningiomas. Vascular/ neural encasement and bone/dural/vascular invasion complicate surgical resection. Nevertheless, it is also likely that meningiomas will become biologically more aggressive with increasing size and tumor cell burden. To prove this hypothesis we studied radiological features of 316 meningiomas and correlated these features with tumor WHO-grade. METHOD 316 meningioma patients who were operated on and who received pathological diagnoses at one single institution were analyzed. Pathological grading was revised by one single neuropathologist according to WHO 2021 criteria. 123 high-grade (WHO grade 2 and 3) patients were initially selected and later substituted with a further 193 age and anatomical-location-matched individuals. Preoperative MRI studies were analyzed for size, hyperostosis, intratumoral calciﬁcation, mass effect, peritumoral edema, shape (globular/en-plaque), lobulation, cystic component, intratumoral heterogeneity, dural tail, and necrosis/hemorrhage. Univariate analysis as well as logistic regression were performed. RESULTS High-grade meningiomas were signiﬁcantly more common to have lobulation (p: 7.111 x 10-8), necrosis/hemorrhage (p: 1.176 x 10-6), peritumoral edema (p: 3.421 x 10-6), intratumoral heterogeneity (p: 1.201 x 10-5), mass effect (p: 0.0002408), and cystic component (p: 0.003519) compared to WHO grade 1 meningiomas. Logistic regression indicated that tumor volume was an independent and signiﬁcant parameter. High-grade tumors were signiﬁcantly larger (40.83 cm3 vs 22.18 cm3, p: 3.518 x 10-6). Skull base meningiomas were of signiﬁcantly lower grade (p: 0.001318). Mean volume was signiﬁcantly higher in high-grade meningiomas. Mean tumor volume varied signiﬁcantly among histopathological subtypes but was highest in anaplastic and atypical subtypes. Tumor volume was strongly correlated with mitosis (p: 2.353 x 10-6), hypercellularity (p: 1.22 x 10-4), spontaneous necrosis (p: 3.273 x 10-4), brain invasion (p: 0.02491), macronucleus (p: 0.05327), small cell (p: 0.09425), and ki-67 levels (p: 2x10-16). CONCLUSION Tumor size is strongly correlated with WHO grade in meningiomas.
CELL-INTRINSIC METABOLIC PHENOTYPES IDENTIﬁED IN GLIOBLASTOMA PATIENTS USING MASS SPECTROMETRY IMAGING OF 13C-LABELED GLUCOSE METABOLISM
Authors: Dr Anastasia Tsyben, Dr Andreas Dannhorn, Dr Gregory Hamm, Dr Dominique Laurent Couturier, Dr Mayen Briggs, Mr Richard Mair, Prof Kevin Brindle
Journal: Neuro-Oncology (2024)

Abstract AIMS Glioblastoma (GB) is an inherently heterogenous and invasive primary brain tumour. Genetic and transcriptomic studies have attempted to classify GB into subtypes that can identify therapeutic vulnerabilities and predict survival. An outstanding question and technical challenge is to visualise the metabolism of a tumour within its native microenvironment and understand to what extent its metabolism is driven by the microenvironment. METHOD Patients with GB tumours were infused with [U-13C]glucose and intra-operative multi-regional tumour samples were rapidly snap frozen for metabolic tracing analysis using mass spectrometry imaging (MSI). Tissue microenvironment was assessed using multiplexing of antibodies on immunocytochemistry (IMC) of parallel sections. Isotope tracing in human derived neurospheres and patient derived xenografts were used to conﬁrm the presence of metabolic phenotypes detected in the human samples and to test susceptibility of each phenotype to a panel of drugs targeting cellular metabolism. RESULTS Three metabolic signatures were identiﬁed in patient GB tumours: glycolytic, oxidative and a mixed glycolytic/oxidative phenotype. The phenotypes did not correlate with microenvironmental features, including proliferation rate, immune cell inﬁltration, and vascularisation. The phenotypes were retained when patient derived cells were grown in vitro, or as orthotopically implanted xenografts, and were robust to changes in oxygen concentration, demonstrating their cell intrinsic nature. The spatial extent of the regions occupied by cells displaying these distinct metabolic phenotypes are large enough to be detected using clinically applicable metabolic imaging techniques. The phenotypes also demonstrate differential drug sensitivities. CONCLUSION This is the ﬁrst report to demonstrate high resolution imaging of metabolic ﬂuxes in a human tumour in vivo. In conjunction with studies on patient-derived neurospheres and orthotopically implanted xenografts we have demonstrated the presence of different metabolic phenotypes within GB that are tumour cell intrinsic and largely independent of the tumour microenvironment. These can be imaged clinically and used to stratify patients for personalised therapy.
DEVELOPING CEREBROSPINAL ﬂUID METABOLOMIC BIOMARKERS FOR MINIMAL RESIDUAL DISEASE AND RELAPSE IN EPENDYMOMA AND MEDULLOBLASTOMA
Authors: Dr Alison Whitby, Mrs Bhoomi Shastri, Prof Christina Halsey, Prof Richard Grundy, Dr Dong-Hyun Kim, Dr Madhumita Dandapani
Journal: Neuro-Oncology (2024)

Abstract AIMS Relapse rates of 30% and 50% in medulloblastoma and ependymoma lead to poor outcomes for paediatric brain tumours. Occurring usually within two years, relapses imply minimal residual disease (MRD) is present below the imaging detection threshold. Patient outcomes might be improved by diagnosing MRD using a sensitive, minimally invasive cerebrospinal ﬂuid (CSF) liquid biopsy, as CSF is proximal to tumour. Metabolites arising from aberrant cancer metabolism may be biomarkers in CSF. METHOD With only 25µl CSF, extracted with 75µl methanol, liquid chromatography coupled with tandem high-resolution mass spectrometry (LC-MS/MS) could differentiate these paediatric brain tumours (n=47; day 14 post-surgery) from controls (n=49). RESULTS Fourteen metabolites were increased in abundance in tumours and four decreased compared to controls. These included amino acids and derivatives (n=8), metabolites in one carbon metabolism (n=1), carnitine cycle (n=2), aerobic glycolysis (n=2), purine catabolism (n=2), ascorbate degradation (n=1) and creatinine synthesis (n=2). From those, betaine/creatinine ratio gave an area under the curve (AUC) of 0.96 (excellent) in receiver operating curve analysis. Using a cut-off ratio of 0.1775 for discriminating brain tumours from controls, had sensitivity and speciﬁcity of 92% and 89%. Speciﬁcally identifying tumours, a ratio of betaine/threonate with cut-off 2.1514 discriminated ependymomas from controls (sensitivity/speciﬁcity 92%/91%). A ratio of malic acid/hypoxanthine with cut-off 0.04429 discriminated medulloblastomas from controls (sensitivity/speciﬁcity 100%/98%). Medulloblastomas (n=14) were largely similar to ependymomas (n=33); nevertheless, three metabolites met the criteria of corrected p&amp;lt;0.05. A ratio of glutarate semialdehyde/malic acid with cut-off 0.04243 discriminated ependymomas from medulloblastomas (sensitivity/speciﬁcity 79%/82%) in a good model (AUC 0.85). CONCLUSION This is the ﬁrst report of CSF metabolites in ependymoma. Ratios between metabolites levels could be useful as biomarkers to detect brain tumours and distinguish brain tumour type speciﬁcally and sensitively. Further work to develop a liquid biopsy test for the detection of MRD is ongoing.
DEVELOPMENT OF A HUMAN-SPECIﬁC 3D IN VITRO PAEDIATRIC CEREBELLAR TUMOUR MODEL USING DECELLULARISED BRAIN AUTOPSY TISSUE
Authors: Dr Phoebe McCrorie, Mr Harry Porter, Dr Mohammed Diksin, Dr Cara Moloney, Dr David Scurr, Prof Richard Grundy, Dr Ruman Rahman
Journal: Neuro-Oncology (2024)

Abstract AIMS Group-3 medulloblastoma (MB) is a paediatric cerebellar tumour with a dismal prognosis. Our objective was to establish a 3D in vitro model termed ‘tumoursphere matrix’ to recapitulate physiologically-relevant communication between tumour cells and reactive brain elements, aiming to discern differential gene expression in cancer cells upon co-culture with astrocytes and human brain extracellular matrix (ECM). METHOD Non-disease human autopsy brain was decellularised to generate ECM and extensively characterised to show DNA reduction, ECM ligand retention and compatibility with different cell lines. D283, D341 and D425 cells were co-cultured with primary human cerebellar astrocytes within a PEGDA hydrogel containing decellularised ECM. Following 7 days of culture, co-cultured cells were separated using ﬂuorescence activated cell sorting to generate individual cell populations for transcriptomic analysis. RESULTS ECM characterisation showed a signiﬁcant reduction in cellular material whilst retaining ECM ligands. Reduction of DNA content to 174 ng/mg was corroborated by an absence of nuclei in immunohistochemical staining. Colorimetric assays indicated collagen and glycosaminoglycan retention in decellularised ECM, and immunoﬂuorescence conﬁrmed retention of ﬁbronectin, laminin and hyaluronic acid. Detection of all ECM ligands was cross-validated by Orbitrap-Secondary Ion Mass Spectrometry. Primary human cerebellar astrocytes, D283, D341 and D425 cells were cultured as spheroids within the ECM/PEGDA hydrogel for 7 days with no signiﬁcant decrease in cellular viability. Cytokine and Human Matrix Metalloproteinase (MMP) Antibody Arrays showed retained cytokine and MMP expression in all three cell lines in the presence of ECM material. CONCLUSION We have developed a bespoke 3D model which can co-culture cells for over 7 days, whilst recapitulating the in vivo tumour environment. RNA sequencing on all 3 cell lines in mono and co-culture is currently in progress to identify differentially expressed genes in medulloblastoma cells upon astrocytic and brain ECM crosstalk. We hypothesise that biochemical signalling underlying this communication network will reveal putative therapeutic vulnerabilities.
VALIDATION OF 2HG-TARGETTED MR SPECTROSCOPY FOR IDENTIFYING IDH-MUTANT GLIOMAS
Authors: Mr Michael Langsen, Prof Adam Waldman, Dr Gerard Thompson, Dr Antoine Vallatos, Dr Michael Thrippleton
Journal: Neuro-Oncology (2024)

Abstract AIMS Diffuse gliomas, the most common adult primary brain tumour, are classiﬁed by their histological and molecular characteristics and genetic proﬁle. Isocitrate dehydrogenase (IDH) mutant gliomas correlate with longer mean survival and progression-free survival time. In tumour cells, IDH mutations lead to metabolic changes and the production of oncometabolite 2-hydroxyglutarate (2HG). MR spectroscopy (MRS) can assess metabolic changes in disease states in-vivo and non-invasively. In this study, we demonstrate a validation pathway for two advanced MRS methods to be used as IDH-mutation biomarkers in clinic. METHOD Simulated, phantom, and healthy volunteer experiments were performed to optimise and validate three MRS sequences tuned for measuring 2HG. A PRESS sequence was used with TR/TE of 2500/97 ms aiming at the 2HG peaks around 2.25 ppm. An edited PRESS sequence, named MEGA-PRESS, tailored to 2HG 4.02 ppm peak was used with TR/TE of 3000/68 ms, 128 averages, and with editing pulses at 1.9 and 7.5 ppm. A long TE semi-LASER MRS sequence, with improved voxel localisation, was also used (TR/TE: 2500/110 ms). RESULTS Simulations were performed to ﬁnd optimised sequence parameters and to develop basis sets for analysing the phantom and healthy volunteer acquisitions. Tumour-mimicking phantoms with variable concentrations of 2HG and cystathionine were created and validated with 800 MHz NMR spectroscopy. Phantoms were then used to assess the sensitivity and speciﬁcity of the MRS for 2HG and cystathionine. MEGA-PRESS proved Synthetic in-vivo 2HG spectra, combined from healthy volunteers and simulated or phantom-2HG spectra, were used to assess the spectral quality needed to reliably measure 2HG. CONCLUSION MEGA-PRESS proved to be the most robust MRS method and demonstrated accurate and precise measurement of phantom and synthetic 2HG with acceptable SNR. Clinical validation of the technique will need to be performed on LGG patient population, and the overall accuracy will be compared with patient IDH mutation status.
EXPLORING LOW-DENSITY LIPOPROTEIN RECEPTOR (LDLR) FAMILY IN GLIOBLASTOMA
Authors: Mr Jack Huyton, Dr Christopher George Severin Smith, Dr Jane Alder
Journal: Neuro-Oncology (2024)

Abstract AIMS Cancer and neurodegenerative disease are unlikely to co-exist in the same patient. As glioblastoma is the most prevalent primary brain cancer, our research group is exploring how GBM is affected by genes implicated in Alzheimer’s disease. SorL1 has been established to be an important risk factor for Alzheimer’s disease and our group have shown it to be upregulated in patient derived GBM cells and it contributes to GBM cell migration and proliferation. SorL1 is part of a wider family of low-density lipoprotein receptor (LDLR) family and so my project was to explore the wider family as a potential target for investigation. METHOD The LDLR family were initially investigated using the bioinformatic data bases Xena browser and ivy Glioblastoma Atlas Project (ivyGAP). Xena browser reports RNA expression between healthy tissue samples (GTEX study) and from low grade glioma and glioblastoma and survival analysis while ivyGAP reports gene expression in the different anatomical regions of glioblastoma tumours. RESULTS Following bioinformatics and literature review: LRP1B, LRP5, LRP10 and Sortilin were chosen for further investigation. Western blot and immunocytochemistry were used to explore expression in cell lines SVGP12, U87MG and 1321N1. Sortilin and LRP10 were shown to be down regulated whilst LRP5 showed no signiﬁcant differences between cell lines. CONCLUSION The next step in this project is to explore expression of the LRP family in patient derived cells and normal human astrocytes. As the expression of the LDLR family was region speciﬁc across the tumour (ivyGAP data) future work in the project will explore expression in 3D spheroids and organotypic brain slice cultures, to create a model that better recapitulates the tumour microenvironment to better understand these proteins and their roles in GBM
OPTIC PATHWAY GLIOMAS AFTER TRANSITIONING INTO ADULTHOOD – AN INSTITUTIONAL EXPERIENCE
Authors: Dr Franziska Loebel, Dr Kristian Aquilina
Journal: Neuro-Oncology (2024)

Abstract AIMS Optic pathway gliomas (OPG) are rare tumors affecting the optic nerve and the chiasm that occur predominantly during childhood and are generally managed by pediatric neurosurgeons/ pediatric oncologists. Prognosis is quite good for these benign tumors, and many patients survive into adulthood. While clinical care for these patients in childhood is well-standardized, the clinical course of patients with OPG after transitioning into adulthood is not well studied.We herein aimed to characterize patients with OPG diagnosed in childhood after transitioning into adult neurosurgical care in order in order to ellucidate the clinical course of OPG in adulthood and to identify potential problems with clinical care of these special patients in adult neurosurgery or neuro-oncology services. METHOD Clinical and radiographical data from adult patients (&amp;gt; 16 years of age) with OPG diagnosed in childhood and treated in our institution were collected from patient charts. Descriptive statistics and outcome analysis were performed using commercial statistical software. RESULTS Of 124 patients with OPG diagnosed in childhood, 35 patients transitioned into adulthood. The population included equal distribution of male (18, 51.4%) vs female (17, 48.6%) patients. Median age at diagnosis was 8.0 years (range 0.5 – 15.0) and median age at last follow up was 20.8 years (range 17.1 – 38.6). 12 patients were positive for NF (34.3%). 9 patients had undergone surgery for the OPG (25.7%), 11 had chemotherapy (31.4%) and 15 (42.8%) had received radiotherapy. 8 patients showed an endocrine deﬁciency (22.9%), 4 hypothalamic dysfunction (11.4%) and 8 cognitive/behavioral diﬃculties (22.9%). Visual acuity impairment was detected in 12 patients (34.3%). 9 patients experienced recurrence (25.7%). CONCLUSION Patients with OPG transition into adulthood frequently and experience a wide range of clinical problems. Close neurosurgical/neuro-oncology specialist follow-up is recommendable.