Does radiation dose to the vestibule predict change in balance function and patient perceived dizziness following stereotactic radiotherapy for vestibular schwannoma

Abstract Objective To date, the majority of the vestibular schwannoma (VS) literature has focused on tumor control rates, facial nerve function and hearing preservation. Other factors that have been shown to significantly affect quality-of-life (QOL), such as dizziness, remain understudied. The primary objective of the current study is to investigate the association between radiation dose to the vestibule and post-treatment changes in vestibular function and patient reported dizziness handicap. Materials and methods This is a prospective observational pilot study at a tertiary academic referral center including all subjects that underwent linear accelerator-based stereotactic radiotherapy (SRS) for sporadic VS and completed pre-treatment and post-treatment vestibular testing and Dizziness Handicap Inventory (DHI) questionnaires. Associations between objective vestibular test results, patient-reported DHI scores and radiation dose parameters were investigated. Results Ten patients met inclusion criteria. Tumor control was achieved in all individuals. There were no statistically significant associations or identifiable trends between radiation dose and change in vestibular function or DHI scores. Notably, the four ears receiving the highest vestibular dose had minimal changes in vestibular function tests and DHI scores. Conclusions To the best of our knowledge, no previous reports have described the association between radiation dose to the vestibule and post-treatment changes in vestibular function and patient reported DHI. Based on these preliminary data, radiation dose to the vestibule does not reliably predict change in objective or subjective vestibular outcome measures.