Useful hearing preservation is improved in vestibular schwannoma patients who undergo stereotactic radiosurgery before further hearing deterioration ensues

Introduction The present study evaluates whether hearing deterioration during observation reduces serviceable hearing preservation rates after stereotactic radiosurgery (SRS) in vestibular schwannoma (VS) patients with useful hearing. Methods We retrospectively analyzed 1447 VS patients who underwent SRS between 1992 and 2017. We identified 100 VS patients who had Grade I Gardner- Robertson (GR) hearing at initial diagnosis but were observed without surgery or SRS. We compared hearing after SRS in 67 patients who retained GR Grade I hearing from initial diagnosis to SRS (the hearing maintenance or HM group) to 33 patients whose hearing worsened from GR grade I to grade II (the hearing deterioration or HD group). We also investigated whether a decline in pure tone average (PTA) or speech discrimination score (SDS) before SRS affected hearing preservation after SRS. Results The serviceable hearing (GR I and II) preservation in HM patients was 80%s, 63%, and 51% at 3, 5, and 10 years, respectively. The serviceable hearing preservation in HD patients was 40%, 33%, and 20% at 3, 5, and 10 years, respectively. In multivariate analysis, younger age (< 55 years, p = 0.045) and HM during observation (p = 0.001) improved serviceable hearing preservation rates. Patients whose PTA increased ≥ 15 dB (p = 0.024) or whose SDS declined ≥ 10% (p = 0.019) had reduced serviceable hearing preservation rates. Conclusions Hearing deterioration during observation before SRS reduced long term hearing preservation rate in VS patients with GR grade I hearing at initial diagnosis. SRS before hearing deterioration was recommended for hearing preservation.