Stereotactic radiosurgery and fractionated stereotactic radiotherapy of acoustic neuromas

Stereotactic radiosurgery (SRS) is a neurosurgical field that has become increasingly important in the treatment of acoustic neuromas. Radiosurgical treatment modalities include the Gamma knife, the linear accelerator (LINAC), and the CyberKnife. Gamma knife radiosurgery (GKRS) is still unsurpassed in terms of the spatial accuracy of radiation delivery and has been used for decades in acoustic neuromas (> 18000 patients). In contrast to surgical resection, the goal of SRS is long-term prevention of tumour growth with preservation of neurological function. Radiation-induced neuropathies rarely occur. However, there are essential differences between SRS and fractionated stereotactic radiotherapy (FSR) in terms of both their radiobiological effects and their modes of application. SRS can be performed in an outpatient setting. Neuromas of up to 3 cm in diameter represent potential candidates for SRS or FSR. For larger tumours, cystic lesions and neuromas with brain stem compression, microsurgical resection in experienced neurosurgical centres is still the preferred option. SRS (and FSR) are possible options for patients with tumour progression after subtotal surgery or tumour recurrence, or for patients unable or unwilling to undergo surgery.