Correlations of O6 ‑methylguanine DNA methyltransferase (MGMT) promoter methylation status with magnetic resonance imaging texture features and prognosis of glioblastomas.

Abstract

O6-methylguanine DNA methyltransferase (MGMT) promoter methylation is associated with the prognosis of patients with glioblastomas. With the aim of facilitating the discrimination of glioblastoma molecular phenotypes and improving the accuracy of molecular imaging diagnosis, the present retrospective study analyzed the association between MGMT promoter methylation and glioblastoma magnetic resonance imaging (MRI) texture features and prognosis. A total of 128 patients with pathologically diagnosed glioblastoma who had undergone preoperative MRI were enrolled. MRI texture features were extracted using 3D Slicer software and their relationship with MGMT promoter methylation was evaluated. In total, seven MRI texture features were significantly different between glioblastomas with methylated and unmethylated MGMT promoters-energy, entropy, uniformity, autocorrelation, and variance in gray level co-occurrence matrix, gray level non-uniformity and cluster shade. Glioblastomas with methylated and unmethylated MGMT promoters differed in tumor location, with the former predominantly located in the temporal lobe [Model I, area under the curve (AUC): 0.697]. Among MRI texture features, variance was significantly different between methylation groups (Model II, AUC: 0.838). Significant overall survival (OS) differences were noticed between patients with methylated and unmethylated MGMT promoters, between patients with preoperative Karnofsky performance status (KPS) scores ≥80 and <80, and among patients with glioblastoma who received radiotherapy, chemotherapy, or concurrent chemoradiotherapy. The seven MRI texture features may serve as independent predictors of prognosis for patients with glioblastoma with methylated MGMT promoters. MRI texture features demonstrated improved and more accurate diagnostic performance than MRI features regarding MGMT promoter methylation status prediction. For patients with glioblastoma with preoperative KPS scores ≥80, those with methylated MGMT promoters had significantly longer OS. Concurrent chemoradiotherapy had a significantly improved prognosis than either radiotherapy or chemotherapy alone. In summary, the present study provided a non-invasive, cost-effective method for detecting MGMT promoter methylation and can significantly contribute to personalized treatment planning for patients with glioblastoma, potentially improving their quality of life.