IDH1 and neoplasm: By performing multivariate Cox analysis considering the variables with a significant p value in univariate analysis, EOR (p = 0.000), age (p = 0.002), methylation status of MGMT promoter (p = 0.000) and preoperative ΔT1/T2 MRI Index (p = 0.000) were confirmed as independent predictors for PFS, however, no correlation was observed with other observed variables such as sex, tumor size and site, IDH-1 status and Ki67% (Figure 3, Table 2).