To evaluate the relationship between fundal fluid and hearing outcomes after treatment of vestibular schwannoma (VS) with Gamma Knife radiosurgery (GKRS).
Retrospective case series.
Tertiary neurotology referral center.
Patients treated with GKRS for vestibular schwannoma between March 2007 and March 2017 were considered for this study. Exclusion criteria included pretreatment pure-tone average (PTA) >90 dB, neurofibromatosis type II, history of previous surgical resection, and follow-up less than 1 year.
Main Outcome Measure(s):
Hearing function was assessed both by preservation of serviceable hearing and by preservation of baseline hearing (≤20 dB change in PTA) after GKRS. Hearing preservation comparisons were made between groups of patients with and without a fundal fluid cap.
Patients with a fundal cap had significantly higher rates of baseline hearing preservation (≤20 dB change in PTA) according to Kaplan–Meier survival analysis of all 106 patients (p = 0.006). By the 3rd year posttreatment, 70.9% of patients with a fundal cap had maintained a ≤20 dB change in PTA, while only 43.6% of patients without a fundal fluid cap achieved this outcome (p = 0.004).
Fundal fluid present on pretreatment magnetic resonance imaging is predictive of improved baseline hearing preservation rates in patients undergoing GKRS for vestibular schwannoma when considering all patients with PTA ≤90 dB. Fundal fluid cap presence may serve as a favorable prognostic indicator to help set hearing expectations and guide patient selection efforts.