The goals of this retrospective cohort study were as follows: 1) to describe the long-term prevalence and timing of hearing deterioration following low-dose (12- to 13-Gy marginal dose) stereotactic radiosurgery (SRS) for vestibular schwannoma (VS); and 2) to identify clinical variables associated with long-term preservation of useful hearing following treatment.
Patients with serviceable hearing who underwent SRS for VS between 1997 and 2002 were studied. Data including radiosurgery treatment plans, tumor characteristics, pre- and posttreatment pure tone average, speech discrimination scores, and American Academy of Otolaryngology–Head and Neck Surgery hearing class were collected. Time to nonserviceable hearing was estimated using the Kaplan-Meier method. Univariate and multivariate associations with time to nonserviceable hearing were evaluated using Cox proportional hazards regression models.
Forty-four patients met the study criteria and were included. The median duration of audiometric follow-up was 9.3 years. Thirty-six patients developed nonserviceable hearing at a mean of 4.2 years following SRS. The Kaplan-Meier estimated rates of serviceable hearing at 1, 3, 5, 7, and 10 years following SRS were 80%, 55%, 48%, 38%, and 23%, respectively. Multivariate analysis revealed that pretreatment ipsilateral pure tone average (p < 0.001) and tumor size (p = 0.009) were statistically significantly associated with time to nonserviceable hearing.
Durable hearing preservation a decade after low-dose SRS for VS occurs in less than one-fourth of patients. Variables including preoperative hearing capacity and tumor size may be used to predict hearing outcomes following treatment. These findings may assist in pretreatment risk disclosure. Furthermore, these data demonstrate the importance of long-term follow-up when reporting audiometric outcomes following SRS for VS.
Abbreviations used in this paper:
AAO-HNS = American Academy of Otolaryngology–Head and Neck Surgery; CPA = cerebellopontine angle; HR = hazard ratio; NF2 = neurofibromatosis Type 2; PTA = pure tone average; SDS = speech discrimination score; SRS = stereotactic radiosurgery; VS = vestibular schwannoma.
BassimMK, , BerlinerKI, , FisherLM, , BrackmannDE, & FriedmanRA: Radiation therapy for the treatment of vestibular schwannoma: a critical evaluation of the state of the literature. Otol Neurotol31:567–573, 2010
BassimMK, BerlinerKI, FisherLM, BrackmannDE, FriedmanRA: Radiation therapy for the treatment of vestibular schwannoma: a critical evaluation of the state of the literature. Otol Neurotol31:567–573, 201010.1097/MAO.0b013e3181d8d3ad)| false
Committee on Hearing and Equilibrium: Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma (vestibular schwannoma). Otolaryngol Head Neck Surg113:179–180, 1995
Committee on Hearing and Equilibrium: Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma (vestibular schwannoma). Otolaryngol Head Neck Surg113:179–180, 199510.1016/S0194-5998(95)70101-X)| false
GoddardJC, SchwartzMS, FriedmanRA: Fundal fluid as a predictor of hearing preservation in the middle cranial fossa approach for vestibular schwannoma. Otol Neurotol31:1128–1134, 201010.1097/MAO.0b013e3181e8fc3f)| false
HasegawaT, KidaY, KatoT, IizukaH, YamamotoT: Factors associated with hearing preservation after Gamma Knife surgery for vestibular schwannomas in patients who retain serviceable hearing. Clinical article. J Neurosurg115:1078–1086, 201110.3171/2011.7.JNS11749)| false
KeminkJL, LangmanAW, NiparkoJK, GrahamMD: Operative management of acoustic neuromas: the priority of neurologic function over complete resection. Otolaryngol Head Neck Surg104:96–99, 199110.1177/019459989110400117)| false