Glioblastoma MRI Dataset with Standardized Preprocessing, Expert-Validated Segmentation, and MGMT Profiling.

Glioblastoma research increasingly relies on large, well-curated imaging datasets that combine standardized MRI data, accurate tumor segmentations, and molecular profiling. We constructed a multi-center dataset of preoperative MRI scans from 337 patients with histologically confirmed primary glioblastoma collected across eight hospitals. All cases include T1-weighted (pre- and post-contrast), T2-weighted, and FLAIR sequences. Images underwent systematic quality assessment, BIDS organization, defacing, skull stripping, and linear registration to the MNI152 template. Tumor segmentation was performed using a SegResNet CNN model following the BraTS labeling convention, with all masks reviewed and manually refined by neuroradiologists. MGMT promoter methylation status was determined for all patients. This dataset provides a robust, clinically representative resource for radiomics, deep learning, and radiogenomic research in glioblastoma, supporting concrete downstream tasks including automated segmentation benchmarking (mean Dice = 0.94) and MGMT methylation prediction (baseline ACC = 0.60). Its multi-center origin, comprehensive preprocessing, expert-refined segmentations, and complete MGMT annotations address limitations of existing datasets and support the development and validation of reproducible imaging biomarkers.