Long-Term Quality of Life and Audiometric Outcomes Following Noninvasive Stereotactic Radiosurgery for Acoustic Neuromas

Abstract

Though microsurgery remains the most common method for management of acoustic neuromas (ANs), stereotactic radiosurgery continues to be a promising alternative. This study assesses long-term quality of life (QOL) outcomes and changes in hearing acuity in patents who have undergone single fraction Gamma Knife stereotactic radiosurgery (GKSRS) for AN.Prospective QOL outcomes were collected and analyzed to include Hearing Handicap Inventory (HHI), Dizziness Handicap Inventory (DHI), Tinnitus Handicap Inventory (THI), and 36-Item Short-Form Survey (SF-36) scores. Likewise, audiometric outcomes including speech discrimination (SD) and pure-tone average (PTA) were assessed. These data points were collected prior to and following GKSRS at regular intervals up to 5 years post-treatment. A mixed effects model for repeated measures was employed to assess QOL data for statistical significance.A total of 235 patients underwent GKSRS for AN at our institution from January 2007 to January 2017. Of these, 130 patients had available QOL and audiometric follow-up data and were included in this study. Median age was 60 y and median follow-up time was 36 mo. Median tumor size was 1.6 cm (0.1 - 3.6 cm), with median tumor volume of 0.552 cm3 (0.028 - 11.31 cm3), while median cochlear mean dose was 2.4 Gy (0 - 9.7 Gy). Baseline mean (median) HHI, DHI, THI, and SF-36 scores were 31.7 (28), 19.3 (12), 18.2 (12), and 70.0 (73.4) respectively. For each of these QOL metrics, mixed effects analysis indicated no statistically significant decline at any time point out to 5 years post-treatment. Indeed, 87% of patients had baseline SD and PTA scores available; 70% had follow-up SD and PTA available. Of these, 59% had baseline serviceable hearing (Gardner-Robertson score of I or II). Serviceable hearing was preserved in 71% of patients at 1 month, 79% at 6 months, 79% at 12 months, 62% at 18 months, 67% at 24 months, and 68% at 36 months.GKSRS provides long-term maintenance of QOL in the treatment of AN. HHI, DHI, THI, and SF-36 scores showed no significant decline up to 5 years post-radiosurgery. Patients with baseline serviceable hearing exhibited adequate hearing preservation.J.S. Lee: None. K.C. Lee: Royalty; Regents of the University of Michigan. Patent/License Fees/Copyright; Regents of the University of Michigan. D. Bojrab: None. P.Y. Chen: Stock; Greater Michigan Gamma Knife (GMGK). J. Jacob: None. I.S. Grills: Greater Michigan Gamma Knife.