The success of volumetric means ADC in predicting MGMT promoter hypermethylation in glioblastomas

Abstract

Aims: This study aimed to investigate the relationship between volumetric mean ADC values and MGMT promoter hypermethylation status in glioblastoma (GB) patients segmented into perilesional edema area, solid tumor area, and necrosis area.
 Methods: The 212 GB patients in the University of California San Francisco Preoperative Diffuse Glioma MRI (UCSF-PDGM) dataset were retrieved from the Cancer Imaging Archive (TCIA). The mean volumetric ADC value was calculated in patients with shared segmentation data in the UCSF-PDGM dataset. The difference in mean volumetric ADC value was investigated in patients divided into groups based on MGMT promoter hypermethylation (MGMT+/ MGMT-).
 Results: Of the patients in our study, 125 (59.0%) were male. The median age of the patients was 62 years (26-94). MGMT promoter hypermethylation was observed in 152 (71.7%) patients. Mean Survival was calculated as 574.14±345.57 days in the MGMT+ group and 484.68±301.71 days in MGMT- group. According to volumetric mean ADC values, a difference was observed in the solid tumor and perilesional edema areas according to MGMT promoter hypermethylation (p1.14 in ADC measurements from the edema area with 72% sensitivity and 90% specificity. MGMT+ group could be determined with a sensitivity of 88% and specificity of 69% with a cut-off value of >1.01 in ADC measurements from the solid tumor area.
 Conclusion: Volumetric ADC measurements from the perilesional edema and solid tumor areas revealed higher ADC values in the MGMT+ group.