Gamma Knife Radiation Therapy for Intralabyrinthine SchwannomasNicolas Massager1,2* , Carine Delbrouck1,3 and Daniel Devriendt1
- *Corresponding Author:
- Nicolas Massager
Gamma Knife Center, Erasme University Hospital
Route de Lennik 808, 1070 Brussels, Belgium
E-mail: [email protected]
Received date : May 06, 2014; Accepted date : June 06, 2014; Published date : June 29, 2014
Citation: Massager N, Delbrouck C, Devriendt D (2014) Gamma Knife Radiation Therapy for Intralabyrinthine Schwannomas. J Nucl Med Radiat Ther 5:180. doi: 10.4172/2155-9619.1000180
Copyright: © 2014 Massager N, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Intralabyrinthine schwannoma are rare benign tumors exclusively managed to date with observation or surgical removal. We analyze results of radiosurgical treatment of these lesions.
Methods: Retrospective analysis of medical data of 454 patients with vestibular schwannomas treated by Gamma Knife in our center was performed. We identify 12 patients treated for a schwannoma located partially or totally into the cochleo-vestibular structures. Ten patients with a clinical and radiological follow-up of more than 1 year were selected for further analysis.
Results: Patients had hearing worsening at different stages, sometimes associated with tinnitus, imbalance or vertigo. The median duration of symptoms before treatment was 3.3 years. Anatomical location of the ILS was intravestibular, intracochlear, intravestibulocochlear, transmacular or transmodiolar (2 patients for each location). We cover 100% of the tumor volume in all patients with a mean margin dose of 11.7 Gy (range 11-12 Gy). The mean follow-up duration was 2.8 years (range 1.5-6.5 years). For 5 patients with functional hearing before treatment, 2 patients had unchanged audiological status at last follow-up, 1 patient had moderate hearing worsening, and 2 patients became cophotic (functional hearing preservation rate of 40%). Facial palsy, even partial and transient, did not occur. No patient experienced permanent worsening of tinnitus, imbalance or vertigo after irradiation.
Conclusions: Gamma Knife radiation therapy seems to be a safe and effective treatment alternative to surgery for patients with intralabyrinthine schwannomas. Radiosurgery can be performed in this indication without significant morbidity with the precision of current robotized Gamma Knife.