Can Gamma Knife Radiosurgery be an Alternative Treatment Modality to Surgery for Vestibular Schwannomas?: A Case Report with Critical Review of the Literature

Development of more sophisticated magnetic resonance imaging scans, the chances of finding asymptomatic patients with vestibular schwannomas as with other intracranial pathologies are increasing. Gamma Knife radiosurgery for vestibular schwannomas has been documented as an efficient and safe procedure based on the treatments in worldwide literature. Preservation of hearing, but not tinnitus, is currently achieved by this minimal-invasive, alternative treatment method. A 55 year-old female patient had applied with complaints of intractable tinnitus and hearing loss on her left ear for six months. Audiologic examination of the patient had revealed a severe degree sensorineural hearing loss on left ear (Average air threshold level: 78 dB, average bone threshold level: 68 dB). Then, magnetic resonance imaging with contrast agent was performed to the patient to detect any suspected lesion. On magnetic resonance imaging, the dimensions of the mass were detected as 15x17x16 mm at the left pontocerebellar angle that was compatible with vestibular schwannoma. Gamma knife radiosurgery was applied to the vestibular schwannoma in a referred center. A single-shot with a MRI-targeted dose (Leksell Gamma Knife, Model B, Gamma Plan 8.32) was applied as 12.5 Gy for 50% (range 42-50%) isodose field (maximal dose: 25 Gy) to cover at least 92% of the lesion. In this paper, we discuss the effectiveness and outcomes of gamma knife radiosurgery, introduced recent few decades as a therapeutic method, with review of the literature for vestibular schwannoma’s management with this case.