Space-Occupying Tumor Bed Cysts as a Complication of Modern Treatment for High-Grade Glioma.

Abstract

The management of high-grade glioma (HGG) has been affected by recent landmark trials and is now more proactive. More aggressive treatment leads to hospitalization due to side effects, however. Space-occupying tumor bed cysts have been described, but not systematically assessed. We sought to analyze this complication in a contemporary HGG cohort. We performed a retrospective review of patients with HGG treated between 2007 and 2013, identified patients with space-occupying tumor bed cysts, and reviewed their hospital notes for relevant variables. Statistical analyses were performed, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Tumor bed cysts were found in 12 of 282 patients (4%). The main symptoms were increased intracranial pressure (n= 11), new focal deficits (n= 6), and pseudomeningocele (n= 3), presenting at a median of 19 days since the last resection. Cysts were treated with cystoperitoneal (n= 7) and ventriculoperitoneal (n= 5) shunts, resulting in clinical benefit in 75% of those treated. Intraoperative opening of ventricles is a risk factor, with an OR of 39.339. We propose a classification system comprising 3 cyst types: isolated cyst, cyst with local cerebrospinal fluid (CSF) disturbance, and cyst with global CSF disturbance. In modern neuro-oncology, the rate of tumor bed cysts complicating HGG management appears stable compared with historical data. Shunt implantation is feasible and effective. We propose a classification system as a common data element for comparison across future studies.