Location-Dependent Patient Outcome and Recurrence Patterns in IDH1-Wildtype Glioblastoma.

Recent studies suggest that glioblastomas (GBMs) contacting the subventricular zone (SVZ) as the main adult neurogenic niche confer a dismal prognosis but disregard the unique molecular and prognostic phenotype associated with isocitrate dehydrogenase 1 (IDH1) mutations. We therefore examined location-dependent prognostic factors, growth, and recurrence patterns in a consecutive cohort of 285 IDH1-wildtype GBMs. Based on pre-operative contrast-enhanced MRI, patients were allotted to four location-dependent groups with (SVZ+; groups I, II) and without (SVZ-; groups III, IV) SVZ involvement or with (cortex+; groups I, III) and without (cortex-; groups II, IV) cortical involvement and compared for demographic, treatment, imaging, and survival data at first diagnosis and recurrence. SVZ involvement was associated with lower Karnofsky performance score ( < 0.001), lower frequency of complete resections at first diagnosis ( < 0.0001), and lower non-surgical treatment intensity at recurrence ( < 0.001). Multivariate survival analysis employing a Cox proportional hazards model identified SVZ involvement as an independent prognosticator of inferior overall survival ( < 0.001) and survival after relapse ( = 0.041). In contrast, multifocal growth at first diagnosis ( = 0.031) and recurrence ( < 0.001), as well as distant recurrences ( < 0.0001), was more frequent in cortex+ GBMs. These findings offer the prospect for location-tailored prognostication and treatment based on factors assessable on pre-operative MRI.