Quantitative diffusion and perfusion MRI for non-invasive MYD88/CD79B genotype characterization and prognostic stratification in primary CNS lymphoma

MYD88 and CD79B alterations are key molecular drivers in primary CNS lymphoma (PCNSL), with prognostic and therapeutic implications. This study aimed to investigate the associations of diffusion and perfusion MRI with MYD88/CD79B mutation status and their potential value for prognostic stratification in PCNSL. This retrospective study included 92 patients with PCNSL (60 with MYD88 mutation, 52 with CD79B mutation, and 40 with MYD88/CD79B co-mutation). Quantitative parameters, including ADC min , rADC min , CBV max , and rCBV max , were compared across genomic subtypes. Discriminatory performance was evaluated using ROC analysis with stratified fivefold cross-validation. Prognostic factors for progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier survival analysis with log-rank tests and Cox proportional hazards regression analysis. PCNSL cases with MYD88/CD79B co-mutation status showed significantly lower ADC min and rADC min values, as well as higher CBV max and rCBV max values, compared with non-co-mutation cases, respectively (adjusted P = 0.020, 0.001, 0.001, and < 0.001). Quantitative diffusion and perfusion parameters demonstrated moderate to good cross-validated discriminatory performance for differentiating genomic subtypes, with areas under the curve (AUCs) ranging from 0.652 to 0.861. Out-of-fold imaging-predicted MYD88/CD79B co-mutation status was significantly associated with shorter PFS and OS, and a lower complete response rate (all P < 0.05), consistent with the observed genomic status. Diffusion and perfusion metrics were independently associated with survival outcomes. Quantitative DWI and DSC-PWI parameters may aid non-invasive characterization of MYD88/CD79B mutation status and preliminary prognostic stratification in PCNSL.