Evaluating Radiological Changes in Vestibular Schwannoma Patients Treated With Hypofractionated Stereotactic Radiation Therapy: A Potential Role for a Novel 3-D Quantitative Volumetric Assessment Tool

Abstract

patients. Salvage CT included Bev in 143 (41.6%) patients and further TMZ in 180 (52.3%) patients. Factors associated with poor overall survival (OS) after LF included older age at diagnosis (P<.001), lower KPS (P<.001), initial surgery (P<.001), bilateral (vs unilateral) disease on presentation (P<.001), WHO grade IV (vs III) (P<.001), lack of salvage RT (PZ.024), and lack of salvage Bev (PZ.006). On multivariable analysis, the only treatment-related factor that retained significance for all patients with LF was the use of salvage Bev (HR 0.65, 95% CI: .43-.97, PZ.036). Conclusion: In this large retrospective series of patients with HGG treated with surgery, RT and TMZ had a local failure at 1 year in keeping with other published studies. Bevacizumab was the only physiciancontrolled factor identified associated with improved survival after failure. However, only 11.3% of our cohort received salvage RT. Further controlled studies will be necessary to determine optimal parameters for salvage therapy.