Radiosurgery for vestibular schwannomas

Abstract

Vestibular schwannomas (VS) are benign tumours arising from the 8th cranial nerve. There are various treatment options for these tumours, which depend upon the tumour size and patient age. However, the surgical treatment has been the conventional method of management of these tumours, since they are frequently detected when quite large in size, especially in our country. Gamma knife radiosurgery (GKRS) is frequently reserved for young patients with small and medium-sized VS (<3 cm) and few symptoms. The tumour control dose is the most important consideration in GKRS, with higher doses having a risk for cranial nerve palsies, whereas lower doses leading to non-treatment of the tumour. The accepted tumour control dose ranges from 12 to 16 Gy among the various series with the tumour control rates of from 87% to 98% considered generally acceptable. The preservation of hearing is an issue worthwhile to be taken into account in GKRS and various series reporting this to range from 40% to 80%. The comparison between microsurgery and GKRS is still debatable because of different indications for both forms of therapies. Microsurgery is chosen for large tumours and GKRS for relatively smaller tumours.

Keywords

• gamma knife
• radiosurgery
• tumour
• vestibular schwannomas