Metabolic, Perfusion, and Diffusion Imaging Enhance Diagnosis and Prognosis of H3K27-Altered Diffuse Midline Gliomas

Background: This study aimed to assess the contributions of metabolism, perfusion, and diffusion kurtosis imaging (DKI) to the diagnosis and prognostic prediction of H3K27 -altered diffuse midline gliomas (DMGs). Methods: Between June 2020 and May 2023, 95 patients (mean age 16.98 years; 61.1% female) with brainstem tumors, including 71 H3K27 -altered DMGs and 24 H3K27 wide-type brainstem tumors (referred as non-DMGs), underwent preoperative conventional and advanced MRI (amide proton transfer-weighted [APTw], arterial spin labeling [ASL], and DKI). Logistic and Cox regressions with leave-one-out cross-validation (LOOCV) were used to evaluate the separate and integrated contributions of advanced MRI to diagnostic and prognostic tasks. Results: Advanced MRI techniques significantly improved the diagnostic and prognostic performances for H3K27 -altered DMGs. Specifically, APTw demonstrated predictive value for both diagnosis (odds ratio [OR] = 3.81, p = 0.004) and prognosis (Hazard ratio [HR] = 1.89, p = 0.003). ASL-derived relative cerebral blood flow (rCBF) improved diagnostic (OR = 7.74, p = 0.019) and prognostic (HR = 2.87, p = 0.002) performances. DKI-derived mean diffusivity (MD) was significantly associated with the diagnosis of H3K27 -altered DMGs (OR = 0.03, p = 0.012). Integration of these metrics revealed that APTw (OR = 3.41, p = 0.014) and MD (OR = 0.05, p = 0.049) were independent diagnostic variables of H3K27 -altered DMGs, while APTw (HR = 1.66, p = 0.037) and rCBF (HR = 2.15, p = 0.038) were independent prognostic factors for overall survival (OS). Conclusion: Metabolic, perfusion, and diffusion imaging can improve the diagnosis and prognosis of H3K27 -altered DMGs beyond conventional MRI, which may aid clinical decision-making.