Abstract
BACKGROUND AND PURPOSE: O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in primary and recurrent glioblastoma may change during treatment. The purpose of this study was to correlate MGMT promoter methylation status changes with DWI and DSC PWI features in patients with recurrent glioblastoma after standard treatment.
MATERIALS AND METHODS: Between January 2008 and November 2016, forty patients with histologically confirmed recurrent glioblastoma were enrolled. Patients were divided into 3 groups according to the MGMT promoter methylation status for the initial and recurrent tumors: 2 groups whose MGMT promoter methylation status remained, group methylated (n = 13) or group unmethylated (n = 18), and 1 group whose MGMT promoter methylation status changed from methylated to unmethylated (n = 9). Normalized ADC and normalized relative CBV values were obtained from both the enhancing and nonenhancing regions, from which histogram parameters were calculated. The ANOVA and the Kruskal-Wallis test followed by post hoc tests were performed to compare histogram parameters among the 3 groups. The t test and Mann-Whitney U test were used to compare parameters between group methylated and group methylated to unmethylated. Receiver operating characteristic curve analysis was used to measure the predictive performance of the normalized relative CBV values between the 2 groups.
RESULTS: Group methylated to unmethylated showed significantly higher means and 90th and 95th percentiles of the cumulative normalized relative CBV values of the nonenhancing region of the initial tumor than group methylated and group unmethylated (all P < .05). The mean normalized relative CBV value of the nonenhancing region of the initial tumor was the best predictor of methylation status change (P < .001), with a sensitivity of 77.78% and specificity of 92.31% at a cutoff value of 2.594.
CONCLUSIONS: MGMT promoter methylation status might change in recurrent glioblastoma after standard treatment. The normalized relative CBV values of the nonenhancing region at the first preoperative MR imaging were higher in the MGMT promoter methylation change group from methylation to unmethylation in recurrent glioblastoma.
ABBREVIATIONS:
- CCRT
- concurrent chemoradiation therapy
- EGFR
- epidermal growth factor receptor
- GBM
- glioblastoma
- IDH
- isocitrate dehydrogenase
- MGMT
- O6-methylguanine-DNA methyltransferase; MM = methylated
- MU
- methylation to unmethylation
- nADC
- normalized ADC
- NER
- nonenhancing region
- nrCBV
- normalized relative CBV
- rCBV
- relative CBV
- TMZ
- temozolomide
- UU
- unmethylated
- VASARI
- Visually Accessible Rembrandt Images
- WHO
- World Health Organization
Footnotes
This study was supported by a grant from the Korea Healthcare Technology R&D Projects, Ministry for Health, Welfare & Family Affairs (HI16C1111); the Brain Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (NRF-2016M3C7A1914002); National Research Foundation of Korea funded by the Korea government (MSIT) (NRF-2020R1G1A11027701); the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (NRF-2020R1A2C2008949 and NRF-2020R1A4A1018714); the Creative-Pioneering Researchers Program through Seoul National University; and the Institute for Basic Science (IBS-R006-A1).
Disclosures: Seung Hong Choi—RELATED: Grant: governmental grants.* Chul-Kee Park—UNRELATED: Employment: Seoul National University Hospital. *Money paid to the institution.
- © 2021 by American Journal of Neuroradiology
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