RELATIONSHIP BETWEEN O(6)-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT) PROMOTER METHYLATION STATUS AND TUMOR SIZE ON PREOPERATIVE CONTRAST ENHANCED MRI IN PATIENTS WITH GLIOBLASTOMA MULTIFORME – SINGLE INSTITUTION EXPERIENCE

Abstract

Introduction. O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status is considered as an important prognostic marker in patients with glioblastoma multiforme. Patients with methylated MGMT promoter are considered that have better prognosis, have longer disease free survival and overall survival. Methods. We performed retrospective analysis of 28 patients with glioblastoma multiforme intended to be treated with radiotherapy and with known MGMT promoter status. Volume of the tumor was measured on initial MR of the brain and it was delineated on transversal MR image DICOM datasets. “Tumor” was defined as contrast enhanced region in T1 weighted image after application of i.v. contrast. Results. From 28 patients, 14 patients were with methylated MGMT promotor (MGMT-M) and 14 with wild type MGMT promotor (MGMT-W). Mean MRI tumor volume in MGMT-M group was 45.41 cm3 (range 4.50 cm3 – 95.26 cm3) and in MGMT-W group 50.46 cm3 (range 3.81 cm3 – 134.79 cm3). Comparison of volumes of 2 groups has shown that there are no significant differences between tumor volumes in the groups p= 0.29864. Conclusion. In our study we can conclude that there is no correlation between MGMT methylation status and initial tumor volume in patients with glioblastoma multiforme.