ID #1089 Neuroimaging Features of Newly Diagnosed Pediatric Posterior Fossa Low-Grade Glioma with Delayed Diagnosis.

Abstract Objective To assess differences in neuroimaging characteristics of newly diagnosed posterior fossa low-grade glioma based upon time to diagnosis. Methods We performed a retrospective review of consecutive patients diagnosed with posterior fossa low-grade glioma at Children’s Hospital Orange County from February 2010-May 2023. Delayed diagnosis was defined as time from symptom onset to diagnostic neuroimaging and categorized as no delay to neuroimaging (< 90 days) or delayed neuroimaging (> 90 days). Tumor location (cerebellum vs. brainstem), volume, presence of hydrocephalus, periventricular transependymal edema, 4th ventricular compression, contrast enhancement, peritumoral vasogenic edema, and brainstem compression were analyzed. Results Twenty-two percent of patients (11/49, 73% female, 45% brainstem location, 64% hydrocephalus) had delayed low-grade glioma diagnosis of greater than 90 days. Male sex (25/38, P=.037), the presence of peritumoral vasogenic edema (21/38, P=.035), and tumor contrast enhancement (P=.058) were associated with earlier diagnosis. There was no significant difference in tumor volume (P=.245), hydrocephalus (P=.506), periventricular transependymal edema (P=.668), 4th ventricle compression (P=.572), or brainstem compression (P = 1.00). Among cerebellar low-grade gliomas (N = 37), the delayed imaging cohort was older at diagnosis (P = 0.037). Male sex was associated with earlier diagnosis of brainstem low-grade glioma (P = 0.10). No differences in neuroimaging features were seen based on tumor location. Symptom duration correlated with total tumor volume (P=.017) and cystic tumor volume (P = 0.002). Conclusions Earlier diagnosis of posterior fossa low grade glioma was associated with male sex and peritumoral vasogenic edema. Older age was associated with delayed imaging. Time to neuroimaging correlated with both total tumor and cyst volume. Our findings suggest demographic and neuroradiographic factors may influence time to diagnostic imaging of pediatric low-grade glioma.