Research Presentation Session: Neuro

RPS 611 - Brain tumour imaging: advanced techniques

February 28, 16:30 - 17:30 CET

7 min
Amide proton transfer-weighted imaging (APT-wi) for molecular and survival prediction of diffuse adult gliomas: single-centre retrospective study
Fabio Martino Doniselli, Milan / Italy
Author Block: F. M. Doniselli, M. Moscatelli, M. Verri, R. Pascuzzo, M. Grisoli; Milan/IT
Purpose: The aim of this study was to observe the correlation between APT signal characteristics of low- and high-grade glial neoplasms and the demographic characteristics, mutational status and grading, using first-order statistics.
Methods or Background: We retrospectively included patients treated for brain tumor in our centre between October 2020 and October 2022 if they matched our set criteria, which were the presence of analysable pre-operative APT-weighted imaging (APT-wi), or a diagnosis of a glioma of any grade. Volumetric ROI on the whole lesion (“tum_ROI”), on the whole lesion excluding the necrotic component (“les_ROI”) and on necrotic component alone - if present (“nec_ROI”) - were placed; from each ROI, the mean, median, standard deviation, 10th percentile, 90th percentile, skewness, and kurtosis of APT values were extracted. One-year survival, IDH, grade, and MGMT promoter methylation were recorded.
Results or Findings: 52 patients (median age 56 years, IQR 25-76, 35 males; 5 astrocytoma grade 2, 8 grade 3 astrocytoma and 39 glioblastoma) were included. Median tumour volume was 40.7cm3 (0.38-167.6). Mean APT values in the les_ROI ranged approximately between 1 and 3 while mean APT values in tum_ROI ranged between 1 and 7. Mean and 90th percentile APT values in les_ROI was statistically different between grade 4 and LGG (p=0.042 and p=0.011 respectively) and for 1 year survival (p=0.011 and p=0.012). No statistical significance was found between IDH-wild type and mutated gliomas nor between methylated and unmethylated MGMT promoter tumours.
Conclusion: In our cohort of glioma patients, APT-wi provides useful information to discriminate between tumour gradings as well as one-year survival.
Limitations: The study was limited by the limited cohort of patients, which occurred as it was a single-centre study.
Funding for this study: No funding was received.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This was a retrospective study.
7 min
Decoding malignant glioma heterogeneity by PET-MRI habitat analysis of HYpoxia, PERfusion and DIffusion imaging: preliminary results of the HYPERDIrect study
Antonella Castellano, Milan / Italy
Author Block: G. Nocera, N. Pecco, M. Bailo, M. Callea, P. V. Scifo, P. Della Rosa, F. Gagliardi, A. Falini, A. Castellano; Milan/IT
Purpose: Malignant gliomas are characterised by considerable intratumour heterogeneity, directly related to treatment failure. A novel method for cancer detection involves identifying regions or habitats within tumours by assessing shared imaging characteristics. This approach utilises quantitative analysis of conventional and advanced imaging data through mathematical models, which effectively partition the tumour into voxel-based subregions exhibiting similar radiological features. The integration of multiple images further refines the creation of distinct tumour habitats. In this study, habitat analysis has been applied on hybrid PET/MR images to map hypoxia, neoangiogenesis, cellularity, and tumour metabolism.
Methods or Background: Twenty patients with suspected malignant glioma candidate for surgical resection or biopsy underwent preoperative hybrid 3T PET/MRI acquisitions for assessing HYpoxia (using quantitative blood oxygenation level-dependent – q-BOLD imaging), PErfusion (using Dynamic Contrast-Enhanced DCE-MRI), DIffusion (usng DTI), and methionine-PET for tumour metabolism. Data obtained were processed to generate HYPERDIrect habitat maps. In FLAIR-derived tumour volumes, an automatic clustering algorithm classified voxels of each quantitative map into two clusters (high and low intensity) . The combination of the clusters from all maps identified eight distinct habitats. Maps were imported into the neuronavigational system to perform imaging-guided sampling for histopathological correlation.
Results or Findings: Preliminary findings demonstrated high habitat imaging reproducibility and a reliable correlation between the expected microenvironment of the different habitats and the actual histopathological characteristics: samples from more aggressive habitats (with reduced diffusivity, high perfusion, and low hypoxia) histologically coincide with regions displaying elevated cell density and increased microvascular proliferation. Samples from less aggressive habitats (high diffusivity, low perfusion, and low hypoxia) correspond to glioma infiltrative areas.
Conclusion: Habitat imaging using the HYPERDIrect map approach might serve as a potential biomarker for non-invasively characterizing tumour heterogeneity in vivo.
Limitations: No limitations were identified.
Funding for this study: Funding was received from the Italian Ministry of Health, grant number GR-2018-12365670.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Ethics Committee of Ospedale San Raffaele on March 9th, 2022 (code 19/INT/2022).
7 min
Vasari-based features nomogram to predict the tumour-infiltrating CD8+ T cell levels in glioblastoma
Caiqiang Xue, Lanzhou / China
Author Block: C. Xue, J. Zhou; Lanzhou/CN
Purpose: Tumour-infiltrating CD8+ T cells play a key role in glioblastoma development, malignant progression, and recurrence. This study sought to establish nomograms based on the Visually AcceSAble Rembrandt Images (VASARI) features of multiparametric magnetic resonance imaging (MRI), to determine the expression levels of tumour-infiltrating CD8+ T cells in patients with glioblastoma.c
Methods or Background: Pathological and imaging data of 140 patients with glioblastoma confirmed by surgery and pathology were retrospectively analysed. The levels of tumour-infiltrating CD8+ T cells in tumour tissue samples obtained from patients were quantified using immunohistochemical staining. Patients were divided into high and low CD8 expression groups. The MRI images of patients with glioblastoma were analysed by two radiologists using the VASARI scoring system.
Results or Findings: A total of 25 MRI-based VASARI imaging features were evaluated by two neuroradiologists. The features with the greatest predictive power for CD8 expression levels were cystic (OR, 3.063; 95% CI: 1.387, 6.766; P=0.006), haemorrhage (OR, 2.980; 95% CI: 1.172, 7.575; P=0.022), and ependymal extension (OR, 0.257; 95% CI: 0.114 0.581; P=0.001). A logistic regression model based on these three features showed better sample predictive performance (AUC=0.745; 95% CI: 0.665, 0.825; Sensitivity=0.527; Specificity=0.857).
Conclusion: The VASARI feature-based nomogram model shows promise in predicting the level of infiltrative CD8 expression in GB tumours noninvasively for earlier tissue diagnosis and more aggressive treatment.
Limitations: This study was limited by the lack of data, all from one centre. Further studies were not conducted in combination with multimodal MRI metrics. The predictive performance of the parameters included in this study was not high and may be improved in future studies using artificial intelligence methods.
Funding for this study: Funding was received from the National Natural Science Foundation of China (grant number 82071872).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Lanzhou University Second Hospital (Approval No. 2020A-070).
7 min
Assessment of axonal fibre integrity using DWI MRI models in post-surgery low-grade glioma patients
Chris W.J. Van der Weijden, Groningen / Netherlands
Author Block: A. Van Der Hoorn, H. L. Van der Weide, M. Kramer, J. Kłos, R. Borra, E. De Vries, C. W. Van der Weijden; Groningen/NL
Purpose: Diffusion-weighted imaging (DWI) using MRI is commonly used for characterising and monitoring patients with low-grade glioma (LGG). Advanced DWI models can potentially provide more detailed microstructural information than traditional DWI parameters. This study aims to establish the relationship between outcome parameters derived from advanced DWI models, and to assess the parameter reliability of these models in post-surgery LGG-patients.
Methods or Background: The study involved 14 post-surgery LGG-patients and 6 healthy controls (HC) who underwent DWI and T2w-FLAIR-MRI scans. Several DWI modeling approaches (diffusion tensor imaging, DTI; diffusion kurtosis imaging, DKI; white matter tract integrity, WMTI; neurite orientation dispersion and density imaging, NODDI; fixel based analysis, FBA) were employed to extract parameters like fractional anisotropy (FA), intracellular diffusivity (ICD), axonal water fraction (AWF), and fibre density (FD). These parameters were chosen to assess axonal fibre integrity, which should be absent in the surgical cavity, affected in the perisurgical cavity (hyperintensity on T2w-FLAIR-MRI), and unaffected in normal appearing white matter (NAWM) of LGG-patients and WM of HC.
Results or Findings: All parameters were significantly different between different tissues, with a gradient of low (DTI-FA, DKI-FA, WMTI-ICD, WMTI-AWF) or no signal (NODDI-ICD, FBA-FD) in the surgical cavity, to medium signal in peri-surgical cavity, and high signal in NAWM/WM. Spearman correlations revealed that all parameters corresponded well with each other (R2=0.69-0.99).
Conclusion: The results of WMTI-ICD and WMTI-AWF suggest the presence of intracellular diffusivity in the surgical cavity, probably because the model does not account for cerebrospinal fluid. These WMTI-data and the high agreement between parameters derived from different models suggest that if only diffusivity direction is required, DTI-FA might suffice. Should one would like to measure intracellular water specifically, then NODDI-ICD would be the better alternative.
Limitations: No limitations were identified.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Medical Ethics Review Board (METc) of the University Medical Centre, Groningen.
7 min
Predictive value of cellular metabolism parameters derived from perfusion MRI for the overall survival of patients with glioblastoma
Chris W.J. Van der Weijden, Groningen / Netherlands
Author Block: C. W. Van der Weijden, R. Borra, E. De Vries, A. Van Der Hoorn; Groningen/NL
Purpose: Perfusion weighted imaging (PWI) with MRI is used to characterise and monitor patients with glioblastoma during and after treatment. Using advanced models, PWI MRI can provide information about metabolism. Metabolic parameters are altered upon tumour growth, making them potential indicators of early tumour progression. This study aims to determine the predictive value of advanced PWI parameters for the overall survival of glioblastoma patients.
Methods or Background: Dynamic susceptibility contrast (DSC) PWI and T1w post-contrast MRI was acquired in 7 patients with post-surgery GBM. PWI was modelled to obtain the mean transit-time (MTT), relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), capillary transit-time heterogeneity (CTH), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) for regions around the surgical cavity. Three perilesion regions were defined on the T1w post-contrast images, respectively at distances of 0-0.5cm, 0.5-1.0cm, and 1.0-1.5cm from the surgical cavity. The outcome parameters were associated with overall survival.
Results or Findings: Visual inspection of the data showed a gradient in the parameters from the surgical cavity outward, albeit not statistically significant. The MTT for perilesion of 0-0.5cm, 0.5-1.0cm, and 1.0-1.5cm distance from the surgical cavity, was 4.2±1.2, 3.6±1.3, 3.5±1.3, rCBV was 2.0±0.6, 2.0±0.5, 2.3±0.7, rCBF was 33.9±11.2, 45.0±15.0, 50.7±7.2, CTH was 4.7±1.2, 4.3±1.5, 4.3±1.4, OEF was 0.4±0.1, 0.4±0.1, 0.4±0.1, and CMRO2 was 12.4±2.8, 14.4±2.7, 16.3±3.4, respectively. None of the parameters were significantly correlated with overall survival.
Conclusion: Although no significant differences were observed yet, the PWI parameters seemed to normalise with greater distance from the surgical cavity. This was even stronger for the currently hardly used CMRO2, although the sample size will be increased to be able to draw firm conclusions.
Limitations: The study was limited by its sample size.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Medical Ethics Review Board (METc) at the University Medical Centre, Groningen.
7 min
Selective vulnerability of cognitive networks in patients with glioma measured by resting-state fMRI
Luca Pasquini, Rome / Italy
Author Block: L. Pasquini1, A. Napolitano2, M. Jenabi1, K. Peck1, M. Schmid2, A. I. Holodny1; 1New York City, NY/US, 2Rome/IT
Purpose: Gliomas affect the whole brain through structural or functional disconnection. This study investigates the impact of gliomas on the cortical synchronisation of brain networks using resting-state fMRI (rs-fMRI). We hypothesised a different vulnerability of brain networks depending on underlying function, tumour location and grade.
Methods or Background: We recruited 147 glioma patients (89M, 50.95±16.13y, 92 high-grade, 55 low-grade) and 200 healthy controls (HCs) with rs-fMRI. Glioma segmentation was performed using 3D-slicer on FLAIR. Group independent component analysis (ICA) was used to extract spatially independent components (IC), subsequently categorised into their respective networks using NeuroMark fMRI 1.0 atlas. We computed cosine similarity (CS) and ran a permutation test to compare, for each IC, the CS of each patient against the HCs distribution. A Chi-squared test was used to verify the significance of networks alterations, tumour location ,and genetics (p<0.05).
Results or Findings: Out of the 20 network components in HCs, 10.38±1.43 resulted altered in patients, including cognitive control network (CCN); default mode network (DMN); subcortical network (SCN); sensorimotor network; visual network (VN). CCN showed significant alterations with tumours in the temporal lobe (p=0.005), Broca's (p=0.01), and Wernicke's area (p=0.041). Tumours in Wernicke's area also altered the DMN (p=0.04), SCN (p=0.038), and VN (p=0.003). Network alterations persisted with increased distance from the tumour, and were more pronounced with higher WHO-grade (p<0.001).
Conclusion: These results indicate specific vulnerability of cognitive networks to tumour growth. Functional alterations extend beyond tumour boundaries, and increase with WHO-grade. Tumour location in known eloquent areas exerts widespread effects on brain networks.
Limitations: Limitations of this study include its retrospective design and lack of complete neuropsychological testing.
Funding for this study: Funding was received from the National Institutes of Health (NIH): NIH-NIBIB R01 EB022720, NIH-NCI R21 CA220144, NIH-NCI P30 CA008748; MSK Cancer Center Support Grant/Core Grant P30 CA008748.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the local Institutional Research Board's ethics committee with code: (16-360).

This session will not be streamed, nor will it be available on-demand!