Unique Peritumoral Patterns Unveiled by Quantitative Multiparametric MRI and Their Diagnostic and Prognostic Value in...

Malignant gliomas remain among the most challenging brain tumors to manage, with high recurrence rates and difficulty in distinguishing progression from treatment-related changes. While the peritumoral region offers valuable insights into tumor behavior, its quantitative MRI characteristics remain largely underexplored. This study investigated the diagnostic and prognostic value of multiparametric MRI biomarkers from noncontrast-enhancing peritumoral regions, particularly the surrounding nonenhancing FLAIR hyperintensity (SNFH). Thirty-eight patients with treated malignant gliomas underwent amide proton transfer-weighted (APTw) imaging, T₁ and T₂ mapping, and diffusion-weighted imaging. Histogram analysis of signal intensities from the enhancing tumor, immediate SNFH (≤ 10 mm), and distant SNFH regions was performed. Progression cases typically showed APTw hyperintensity in enhancing tumor cores and surrounding SNFH, while response cases showed minimal hyperintensity to isointensity in these regions. Repeated measures ANOVA revealed significant parameter variation across the tumor and SNFH regions, with APTw showing the largest dynamic range. Logistic regression models trained on histogram features from APTw and T₁ maps achieved a maximum test area under the curve (AUC) of 0.79 in differentiating progression from response. In survival analysis, parameters including higher APTw skewness was associated with better overall survival (hazard ratio = 0.32; p = 0.006). These findings demonstrate that APTw and T₁ imaging biomarkers from peritumoral edema regions reflect key features of tumor invasion and metabolic activity. Their combined application has potential to improve diagnostic accuracy and inform prognosis in posttreatment high-grade gliomas.