The Impact of Radiation Therapy Variables on Pediatric High-Grade Glioma Outcomes: A National Cancer Database Analysis

Abstract Purpose Pediatric high-grade glioma (HGG) is a devastating disease with a poor prognosis. The purpose of this analysis is to evaluate the impact of Radiation Therapy (RT) variables on outcomes of pediatric HGG patients in the National Cancer Database (NCDB). Methods The NCDB was used to select patients age < 22 with histologically proven WHO Grade III and IV gliomas treated with ≥ 50Gy and < 76Gy RT between 2004 and 2013. RT variables including RT dose, timing between diagnosis and RT initiation ( 6 weeks), and RT modality were analyzed along with baseline demographic, tumor and treatment variables to assess the impact on overall survival in univariate and multivariable analyses. Results 498 pediatric HGG patients were included. Histologies included glioblastoma (30%), astrocytoma (55%), oligogendroglioma (5%) and gliomas not otherwise specific (10%). The median RT dose was 59.4 Gy (SD 2.9 Gy) starting a median of 4.4 weeks from diagnosis (SD 2.5 weeks). Median follow-up was 19.6 months with 1- and 3-year OS of 78.4% and 40.4%, respectively. On Multivariable analysis, female gender, older age, and private insurance remained independently associated with lower rate of overall death. Radiation initiation ≤ 4 weeks from diagnosis, and glioblastoma histology were significantly associated with higher rate of overall death. There was no relationship between radiation dose or whether radiation was delivered with proton or photon therapy and overall survival. Conclusions Outcomes for pediatric HGG are poor. Early initiation of RT within 4 weeks from diagnosis was negative associated with overall survival and may be related to unknown prognostic factors.