Metabolic, perfusion, and diffusion imaging enhance diagnosis and prognosis of H3K27-altered diffuse midline gliomas

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).

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 wild-type brainstem tumors (referred to 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.

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).

Metabolic, perfusion, and diffusion imaging can improve the diagnosis and prognosis of H3K27-altered DMGs beyond conventional MRI, which may aid clinical decision-making.