Vestibular schwannoma (formerly known as acoustic neuroma) is a benign, usually slow-growing tumour which typically develops from the vestibular nerve (balance nerve) [1]. About 8% of all intracranial tumours are vestibular schwannomas, more than 90% of which are unilateral [1,2]. The condition is usually diagnosed at the age of about 50 years [1,2]. Its incidence is 1 to 2 cases per 100 000 population per year [1]. Symptoms include, in particular, hearing deficits, tinnitus, dizziness, and facial paraesthesia [1,2].

The exact aetiology of vestibular schwannoma is unknown. Potential risk factors include low-dose radiation for benign diseases of the head and neck during childhood, the use of mobile phones, and noise exposure [2]. In this context, neurofibromatosis type 2 represents a special case because 90% to 95% of patients with this genetic condition develop bilateral vestibular schwannoma [3]. These bilateral tumours are usually diagnosed at an age of about 30 years [3].

Vestibular schwannoma can be stratified according to the Hannover, House, Koos, or Sterkers classification system, which are each based on the size and extension of the tumour [1]. The primary diagnostic tool is typically magnetic resonance imaging (MRI) [1].

The choice of treatment method is largely based on tumour characteristics (size, location, and growth), patient history, and patient preference [1,4-7]. Options include watchful waiting, microsurgical resection, radiotherapy, and a combination thereof [1,2,7]. Watchful waiting requires periodic MRI scans about every 12 months and is an option particularly suitable for small, non-growing, asymptomatic tumours. Radiotherapy is an alternative for older patients and those with high surgical risk [1,2]. Microsurgery is typically used to treat symptomatic and/or larger space-occupying lesions; depending on tumour location, it involves a transtemporal, translabyrinthine, suboccipital, or retrosigmoidal approach [1,2]. For radiotherapy of vestibular schwannoma, single-session stereotactic radiosurgery (SRS) with linear accelerators or cobalt-60 gamma sources is available, among others. It involves immobilizing the head and exposing the target tissue in the head to precisely-targeted, high-dose radiation in a single session [2,8].