Abstract Background Intratumor heterogeneity (ITH) is closely associated with poor prognosis in high-grade gliomas (HGGs). This study aimed to characterize ITH and explore potential imaging markers that predict overall survival (OS) in HGGs using intravoxel incoherent motion magnetic resonance imaging (IVIM MRI)-based spatially explicit analysis. Methods Sixty-five HGG patients who underwent surgical resection were analyzed. Preoperative IVIM MRI images were collected and processed to obtain true diffusion coefficient ( D ) and perfusion fraction ( f ) maps. Tumor regions of interest were segmented, and the k-means algorithm was applied to cluster the D and f image voxels for generating spatial habitats and extracting quantitative image features. Kaplan-Meier analysis and Cox proportional hazards were used to compare variables and patient subgroups. Results Three spatial habitats were identified: Habitat 1 (hypo-vascular, hyper-cellular), Habitat 2 (hypo-cellular), and Habitat 3 (hyper-vascular). In the multivariate Cox regression analysis, isocitrate dehydrogenase (IDH) genotype (hazard ratio HR = 0.298, P = 0.003) and volume percentage (pVol) of Habitat 1 (HR = 6.155, P = 0.01) showed prognostic significance, with the model yielding a concordance index of 0.756. A pVol value of Habitat 1 below 47.6% predicted survival benefits in patients with HGG and IDH wild-type gliomas, as well as in those with HGG who underwent subtotal resection (median OS improvement: 11, 11, and 8 months, respectively). Conclusions Spatial habitats identified via IVIM MRI may aid in characterizing cellular and vascular heterogeneity in HGGs, with the pVol of hypo-vascular, hyper-cellular habitat potentially serving as an independent predictor of patient survival.
Wang et al. (Fri,) studied this question.