MR Elastography Analysis of Glioma Stiffness andIDH1-Mutation Status

Abstract

Purpose To noninvasively evaluate gliomas with magnetic resonance elastography (MRE) to characterize the relationship of tumor stiffness with tumor grade and mutations in the IDH1 gene. Materials and Methods With institutional review board approval and following written, informed consent, tumor stiffness properties were prospectively quantified in 18 patients (mean age 42, 6 female) with histologically proven gliomas using MRE from 2014–2016. Images were acquired on a 3T MR unit with a vibration frequency of 60 Hz. Tumor stiffness was compared with unaffected contralateral white matter, across tumor grade and by IDH1 mutation status. The performance of the use of tumor stiffness to predict tumor grade and IDH1 mutation was evaluated by using Wilcoxon rank sum, one-way ANOVA and Tukey-Kramer tests. Results Gliomas were softer than healthy brain parenchyma, 2.2 kPa compared to 3.3 kPa (p < .0001) with grade IV tumors softer than grade II. Tumors with an IDH1 mutation were significantly stiffer than those with wild-type IDH1, 2.5 kPa vs. 1.6 kPa respectively (p = .007). Conclusions MRE demonstrated that gliomas were not only softer than normal brain but the degree of softening was directly correlated with tumor grade and IDH1 mutation status. Noninvasive determination of tumor grade and IDH1 mutation may result in improved stratification of patients for different treatment options and the evaluation of novel therapeutics. This work reports on the emerging field of mechanogenomics – the identification of genetic features such as IDH1 mutation using intrinsic biomechanical information.

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“…Clinical applications of MRE measurements of tumor mechanical stiffness have shown significant potential for clinical cancer staging and treatment response assessment . In a recent study by Gordic et al, MRE was used to assess tumor stiffness following locoregional therapy for hepatocellular carcinoma .…”

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