Phosphorous Magnetic Resonance Spectroscopy to Detect Regional Differences of Energy and Membrane Metabolism in Naïve Glioblastoma Multiforme
by
, ,
Lisa Maria Walchhofer
1,2,†, 
Ruth Steiger
1,2,†,
Andreas Rietzler
1,2,*,
Johannes Kerschbaumer
3,
Christian Franz Freyschlag
3
,
Günther Stockhammer
4,
Elke Ruth Gizewski
1,2 and
Astrid Ellen Grams
1,2 1
Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria
2
Neuroimaging Research Core Facility, Medical University of Innsbruck, 6020 Innsbruck, Austria
3
Department of Neurosurgery, Medical University of Innsbruck, 6020 Innsbruck, Austria
4
Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria
*
Author to whom correspondence should be addressed.
†
Shared first authorship.
Cancers 2021, 13(11), 2598; https://doi.org/10.3390/cancers13112598
Submission received: 9 February 2021
/
Revised: 14 May 2021
/
Accepted: 21 May 2021
/
Published: 26 May 2021
(This article belongs to the Special Issue Tumor Heterogeneity)
Simple Summary
Glioblastoma multiforme is a highly aggressive brain tumor, tending to infiltrate even larger zones of brain tissue than visible on conventional magnetic resonance imaging. By application of phosphorus magnetic resonance spectroscopy in patients with naïve glioblastoma multiforme, we tried to demonstrate changes in energy and membrane metabolism not only in affected regions but also in distant brain regions, the opposite brain hemisphere, and in comparison to healthy volunteers. We found reduced energetic states and signs of increased cell membrane turnover in regions of visible tumor and differences to and between the “normal-appearing” brains of glioblastoma patients and the brains of healthy volunteers. Our pilot study confirmed the feasibility of the method, so differences between various genetic mutations or clinical applicability for follow-up monitoring can be assessed in larger cohorts.
Abstract
Background: Glioblastoma multiforme (GBM) is a highly malignant primary brain tumor with infiltration of, on conventional imaging, normal-appearing brain parenchyma. Phosphorus magnetic resonance spectroscopy (31P-MRS) enables the investigation of different energy and membrane metabolites. The aim of this study is to investigate regional differences of 31P-metabolites in GBM brains. Methods: In this study, we investigated 32 patients (13 female and 19 male; mean age 63 years) with naïve GBM using 31P-MRS and conventional MRI. Contrast-enhancing (CE), T2-hyperintense, adjacent and distant ipsilateral areas of the contralateral brain and the brains of age- and gender-matched healthy volunteers were assessed. Moreover, the 31P-MRS results were correlated with quantitative diffusion parameters. Results: Several metabolite ratios between the energy-dependent metabolites and/or the membrane metabolites differed significantly between the CE areas, the T2-hyperintense areas, the more distant areas, and even the brains of healthy volunteers. pH values and Mg2+ concentrations were highest in visible tumor areas and decreased with distance from them. These results are in accordance with the literature and correlated with quantitative diffusion parameters. Conclusions: This pilot study shows that 31P-MRS is feasible to show regional differences of energy and membrane metabolism in brains with naïve GBM, particularly between the different “normal-appearing” regions and between the contralateral hemisphere and healthy controls. Differences between various genetic mutations or clinical applicability for follow-up monitoring have to be assessed in a larger cohort.
Keywords:
MRS; magnetic resonance spectroscopy; energy metabolism; glioblastoma; ATP; PCr
