MR Imaging features of Diffuse Intrinsic Pontine Glioma (DIPG) and Relationship to Overall Survival: Report from the International DIPG Registry.

Background This study describes imaging features of diffuse intrinsic pontine glioma (DIPG) and correlates with overall survival (OS) and histone mutation status in the International DIPG registry (IDIPGR). Methods 400 cases submitted to the IDIPGR with a local diagnosis of DIPG and baseline MRI were evaluated by consensus review of two neuroradiologists. 43 cases were excluded (inadequate imaging or alternative diagnoses). Agreement between reviewers, association with histone status, and univariable and multivariable analyses relative to OS were assessed. Results On univariable analysis imaging features significantly associated with worse OS included: extrapontine extension, larger size, enhancement, necrosis, diffusion restriction, and distant disease. 9.5% of patients were considered not to have DIPG on central review. There was moderate mean agreement of MRI features between reviewers. On multivariable analysis chemotherapy, age, and distant disease were predictors of OS. There was no difference in OS between wild-type and H3 mutated cases. The only imaging feature associated with histone status was the presence of ill-defined signal infiltrating pontine fibers. Conclusions Baseline imaging features are assessed in the IDIPGR. There was a 9.5% discordance in DIPG diagnosis between local and central review demonstrating need for central imaging confirmation for prospective trials. Although several imaging features were significantly associated with OS (univariable) only age and distant disease were significant on multivariable analyses. There was limited association of imaging features with histone mutation status although numbers are small and evaluation exploratory.