Statistical Analysis
Descriptive statistics were used to summarize the distribution of each variable and to compare the baseline characteristics of patients. The chi-square and/or Fisher’s exact tests were used to compare differences in categorical variables between patients. The Student t-test and Wilcoxon rank sum nonparametric statistics were used for similar comparisons with continuous variables. All p-values were two tailed with p-values <0.05 considered significant. The Kaplan–Meier (KM) method was used to estimate unadjusted overall survival (OS) probabilities. The log-rank test was used to compare differences in OS between patients with low grade glioma, high grade glioma, those with or without H3K27M mutations and those with or without elevations in citrate levels. Median follow-up time was determined using the reverse KM method. All data analyzed using and R statistical software (R Foundation for Statistical Computing, Vienna, Austria).