In the GBM subgroup, MGMT methylated tumors showed a non-significant trend towards increased 23Na concentrations (23Na concentration median [IQR]: MGMT methylated = 57.59 mM [50.70 – 59.17 mM], MGMT not methylated = 48.78 mM [45.88 – 53.91 mM], p = 1.0) and 23Na MRI did not yield a statistically significant predictor of MGMT status in the consecutive ROC analysis (AUC = 0.63 [95% CI: 0.23 – 1]). Here, MGMT is linked to glioblastoma.