Shorter time to initiation of adjuvant chemoradiation therapy as a risk factor for hydrocephalus following high-grade glioma resection: A case-control study

• The incidence of hydrocephalus within 3 years after high-grade glioma resection in adults is 8.9 %. • The median time to hydrocephalus onset is 5 months postoperatively. • Shorter time to initiation of adjuvant therapy may increase risk of hydrocephalus. While existing literature has explored how timing of adjuvant therapy affects survival in high-grade glioma (HGG) patients, no studies have specifically addressed the relationship between time to initiation (TTI) of therapy and postoperative complications. This study investigates how TTI of adjuvant chemoradiation therapy may impact risk for developing hydrocephalus following HGG resection. A single-center, retrospective study identified 257 adults with HGG undergoing their first tumor resection from 2010 to 2020. Demographic and clinical data were collected, including surgical and adjuvant therapy history. Propensity Score Matching generated comparative cohorts using covariates sex, age at surgery, surgery type, tumor location, extent of resection, tumor-associated seizures, ventricular opening, number of additional surgeries, and pre-surgical Karnofsky Performance Scale score. Odds ratios with 95 % confidence intervals and paired t-tests assessed differences in adjunctive chemoradiation trends between patients who developed hydrocephalus within 3 years postoperatively and those who did not. 23 of 257 patients (8.9 %) who underwent HGG resection developed hydrocephalus, with a median time to onset of 5.1 months (IQR: 1.6–11.9). Of these patients, 15 (65.2 %) developed early-onset hydrocephalus, defined as within 6 months postoperatively, whereas 8 (34.8 %) developed late-onset hydrocephalus after 6 months postoperatively. Patients who developed hydrocephalus were more likely to have a shorter TTI of adjuvant chemoradiotherapy than controls ( P = 0.03), with median time interval of 7.9 (5.6, 12.7) in controls and 5.7 weeks (IQR: 4.1–8.5) in cases. Shortened time to initiation of adjuvant therapy postoperatively may increase patients’ susceptibility for postoperative hydrocephalus following initial HGG resection.