Vestibular Schwannoma Tumor Size Is Associated With Acute Vestibular Symptoms After Gamma Knife Therapy Objective: To assess how pretreatment vestibular schwannoma (VS) tumor characteristics are associated with vestibular symptoms after gamma knife (GK) surgery. Study Design: Retrospective chart review of patients undergoing GK treatment for VS at our institution from 2005 to 2018. Setting: Academic tertiary referral center. Patients: Patients receiving primary GK surgery for vestibular schwannomas with at least 6 months of follow up. Patients with neurofibromatosis 2 or previous surgery were excluded. Main Outcome Measures: The presence of posttreatment vestibular symptoms within 6 months after GK. Clinical records were assessed for pretreatment tumor, patient, and treatment characteristics that impacted posttreatment symptoms. Results: All patients received radiation doses between 12 and 13 Gy. Of 115 patients, the average age was 60. Thirty-seven (32%) patients developed vestibular symptoms within 6 months post-GK, and 18 patients were referred for vestibular rehabilitation. Ten of 13 patients undergoing vestibular rehabilitation reported improvement. Overall, 112 patients had tumor measurements. Pretreatment tumors were significantly smaller for patients with acute vestibular symptoms (mean 1.43 cm versus 1.71 cm, p = 0.007). On multivariate analysis, smaller tumor size (p = 0.009, odds ratio [OR] = 0.29, 95% confidence interval [CI] [0.12–0.73]) was significantly associated with vestibular symptoms within 6 months of GK. Patients with tumors less than 1.6 cm were more likely to receive referrals for vestibular rehabilitation within 6 months posttreatment (25% versus 9.4%, p = 0.026, OR = 3.22, 95% CI [1.00, 11.32]). Conclusions: Smaller vestibular schwannomas were significantly associated with higher rates of post-GK vestibular symptoms. Pretreatment tumor size may be used to counsel patients on the likelihood of post-GK vestibular symptoms and vestibular rehabilitation. Address correspondence and reprint requests to Michael J. Ruckenstein, M.D., M.Sc., Department of Otorhinolaryngology, 3400 Civic Center Blvd, South Pavilion 3rd Floor, Philadelphia, PA 19104; E-mail: michael.ruckenstein@uphs.upenn.edu This work was not funded. Disclosures: J.A.B. is the owner of MobileOptx, LLC and was a consultant for TympBio. M.A.B. received honoraria from Varian. There are no conflicts of interest. Copyright © 2019 by Otology & Neurotology, Inc. Image copyright © 2010 Wolters Kluwer Health/Anatomical Chart Company

Hearing and Quality of Life Over Time in Vestibular Schwannoma Patients: Observation Compared to Stereotactic Radiosurgery Objective: To examine quality of life changes for patients with vestibular schwannoma (VS) undergoing observation or stereotactic radiosurgery (SRS). Study Design: Retrospective review. Setting: Academic medical center. Patients: Patients with VS who underwent observation or SRS and had at least two audiograms and Penn Acoustic Neuroma Quality of Life (PANQOL) surveys, a quality of life survey for patients with VS. Interventions: SRS or observation. Main Outcome Measures: Pure-tone average (PTA), speech discrimination score (SDS), PANQOL score; controlling for tumor size, baseline hearing, and other factors. Results: One hundred twenty-three patients met inclusion criteria: 89 underwent observation and 34 SRS. There was no significant difference in the rate of decline measured by PTA (PTA worsened at a rate of 0.25 dB/yr more in the observation group compared with the SRS group, p = 0.77) and SDS (SDS worsened at a rate of 2.1%/yr more in the SRS group compared with the observation group, p = 0.82). Kaplan–Meier analysis demonstrated the SRS group had a higher probability to progress to class D hearing over observation (hazard ratio 7.1, p = 0.005). The rate of change of the SRS PANQOL scores was significantly improved in the total (p = 0.005) and hearing (p = 0.04) domain score compared with observation. However, both groups regress to a similar PANQOL total and hearing domain score over time. Conclusion: PANQOL scores were higher at baseline in the observation group than in the SRS group. However, over time, PANQOL scores in the observation group decreased while PANQOL scores in the SRS group increased, resulting in PANQOL scores that were equivalent by the end of follow-up. Address correspondence and reprint requests to Lauren E. Miller, M.D., M.B.A., Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114; E-mail: Lauren_miller@meei.harvard.edu The Institutional Review Board at the Hospital of the University of Pennsylvania approved this study (Protocol 814830). The authors disclose no conflicts of interest. Copyright © 2019 by Otology & Neurotology, Inc. Image copyright © 2010 Wolters Kluwer Health/Anatomical Chart Company