Spatial Analysis and Validation of Glioblastoma on 7 T MRI

Study Overview
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Brief Summary
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Currently, patients with a glioblastoma multiforme (GBM) are treated with a combination of different therapeutic modalities including resection, concurrent chemo- and radiotherapy and adjuvant temozolomide. However, survival is still poor and most of these tumours recur within one to two years within the previously irradiated target volume. The radiation target volume encompasses both the contrast-enhanced lesion on T1-weighted magnetic resonance imaging (MRI), plus a 1.5 - 2 cm isotropic margin in order to include microscopic speculated growth. These margins result in a high dose to surrounding healthy appearing brain tissue. Moreover, the short progression-free survival indicates a possible geographical miss. There is a clear need for novel imaging techniques in order to better determine the degree of tumour extent at the time of treatment and to minimize the dose to healthy brain tissue. The development of Ultra-High Field (UHF) MRI at a magnetic field strength of 7 Tesla (T) provides an increased ability to detect, quantify and monitor tumour activity and determine post-treatment effects on the normal brain tissue as a result of a higher resolution, greater coverage and shorter scan times compared to 1.5 T and 3 T images. Up to now, only few investigators have examined the use of UHF MRI in patients with malignant brain tumours. These studies show its potential to assess tumour microvasculature and post-radiation effects such as microhaemorrhages. This study analyzes the accuracy of the 7T MRI in identifying the gross tumour volume (GTV) in patients with an untreated GBM by comparing biopsy results to 7T images. These biopsies will be taken from suspected regions of GBM based on 7T MRI that do not appear as such on 3T MRI. We hypothesize that with the 7T MRI the GTV can be more accurately and extensively identified when compared to the 3T MRI.

Official Title
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Spatial Analysis and Validation of Glioblastoma on 7 T MRI

Conditions
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Glioblastoma

Intervention / Treatment
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* Device: 7 T MRI
* Procedure: Biopsy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Supratentorial tumour Suspected GBM on diagnostic MRI Eligible for biopsy Minimum age 18 years or older World Health Organization (WHO) Performance scale ≤2 American Society of Anaesthesiologist (ASA) class ≤ 3 Understanding of the Dutch language Ability to comply to study procedure Exclusion Criteria: Recurrent tumour Tumour location deemed unfit for extra biopsies Prior radiotherapy to the skull Prior chemotherapy World Health Organization (WHO) Performance scale ≥ 3 American Society of Anaesthesiologist (ASA) class ≥ 3 Eligibility for immediate debulking Contra-indications for gadolinium Contra-indications for the MRI

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Biopsy<br>Subjects will receive a 7 T MRI and one additional biopsy to their standard diagnostic biopsies | Device: 7 T MRI<br>* Overview Technical DetailsField strength: 7 Tesla Bore size: 60 cm System length: 317,5 cm RF power: 7,5 kW / 8x1 kW Gradient strength: SC 72 Gradients (max. 70 mT/m @ 200 T/m/s) Helium Consumption: Zero Helium boil-off technology<br>* Other names: Siemens MAGNETOM 7;Procedure: Biopsy<br>* During surgery patients will receive standard biopsies plus one study biopsy from a region of interest. The neuro-surgeon will determine the feasibility of the extra biopsy and the optimal biopsy tract. A screen capture from the neuronavigation system will be saved for each biopsy to relate the findings on 3T and 7T MRI to histopathology.<br>* Other names: Tumor sampling;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The co-localisation of the Gross Tumour Volume (GTV) on 7T MRI and 3T MRI | The spatial overlap in GTV between 7T MRI and 3T MRI as well as inter- and intra-observer variability will be measured with the Dice Similarity Coefficient (DSC) and the mean of the slice-wise Hausdorff distances. | Six months after biopsy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The correspondence between glioblastoma cells found in the biopsies and region of interest (ROI) on the 7T MRI scan. | Pathological assessment of biopsy material compared with the ROI on 7T MRI | Within a month after biopsy | 
| The co-localisation of the Clinical Target Volume (CTV) on 7T MRI and 3T MRI | The CTV includes the GTV plus a 1.5 cm isotropic margin and is adjusted to the anatomical borders and may be reduced in regions adjacent to sensitive structures. The spatial overlap in CTV between 7T and 3T MRI as well as inter- and intraobserver variability will be measured with the DSC and the mean of the slice wise Hausdorff distances. | Six months after the biopsy | 
| The co-localisation of the organs at risk (OAR) on 7T - and 3T MRI | The OARs (chiasm, optic nerves, pituitary gland, (subfields of) hippocampal formation and brainstem) will be delineated by 2 radiation-oncologists, a resident radiation-oncology, a radiation technologist and a neuroradiologist. The spatial overlap in OARs between 7T and 3T MRI as well as inter- and intraobserver variability measured by the DSC and the mean of the slice-wise Hausdorff distances. | Six months after biopsy | 
| The correlation between the first tumour recurrence on 3T MRI follow-up images and ROI on the 7T MRI scan | The correlation between the first tumour recurrence on 3T MRI (perfusion) follow-up images and ROI on the pre-biopsy 7T MRI scan will be measured with the DSC and the mean of the slice-wise Hausdorff distances. | approx. one month after tumour recurrence | 
| The quantification of tumour heterogeneity on 7T MRI and 3T MRI | Quantification of tumour heterogeneity advanced Radiomics computer software that has been developed within Maastricht Radiation Oncology | Six months after biopsy | 
| The visibility of white matter tracts on 7T MRI and 3T MRI | Visualization of white matter tracts will be done with the use of diffusion tensor imaging (DTI) on 7T MRI. | Six months after the biopsy | 
| Tolerability and side effects 3T MRI and 7T MRI scan | The tolerability and side effects will be evaluated with the comparison of two short questionnaires following the 3T and the 7T MRI scans | After 3T MRI and 7T MRI | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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7 T MRI, Radiotherapy, Glioblastoma, Biopsy