Exploring the Role of Advanced MRI in Understanding Glioblastoma Biology: A Scoping Review

Among adult primary brain tumours, glioblastoma (GBM) carries the worst prognosis. Magnetic resonance imaging (MRI) serves to diagnose and guide treatment, despite recognised constraints. Advanced MRI techniques-magnetic resonance spectroscopy (MRS), amide proton transfer-weighted imaging (APTw), diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), and quantitative susceptibility mapping (QSM)-reveal GBM characteristics that conventional sequences cannot detect. The 2021 World Health Organization reclassification disrupted established imaging-biology relationships, necessitating isocitrate dehydrogenase wildtype (IDHwt) GBM-specific evidence integration. This review synthesises biological insights provided by advanced MRI in preoperative IDHwt GBM.

We conducted a scoping review following the PRISMA-ScR framework, querying five databases (PubMed, Scopus, Cochrane, EBSCO, and Embase) to identify literature using advanced MRI to investigate biological correlates in IDHwt GBM.

MRS ratios were associated with tumour presence and Ki-67 expression. APTw demonstrated robust associations with cellularity but failed to predict O6-methylguanine-DNA methyltransferase promoter (MGMTp) methylation. DWI exhibited variable utility; certain metrics linked to cellularity, while apparent diffusion coefficient values were inconsistent but useful for predicting MGMTp status, telomerase reverse transcriptase promoter mutations, and CD163+ macrophage infiltration. PWI showed relationships with cellularity, micro-vessel area, and MGMTp status. QSM features correlated with Ki-67, ferritin, and immune markers.

Advanced MRI demonstrates potential for biological stratification of GBM, though protocol variability and limited reproducibility hinder clinical translation. Standardised pipelines and prospective multicentre validation must precede clinical adoption, before these techniques can benefit patients.