Surgery of Vestibular Schwannomas in the Era of with Gamma-Knife Radiosurgery: A Two-Center Comparative Study with 702 Cases

Background The three treatment options currently considered for vestibular schwannoma are expectant treatment, microsurgery, and radiosurgery, and to date no class I evidence favors one treatment over the others.

Objective The objective of this study was to compare functional outcome following surgical treatment versus gamma knife (GK) radiosurgery.

Methods A group of 275 patients submitted to microsurgery and 427 patients treated with radiosurgery in two different centers were followed up for 15.2 and 45.6 months, respectively. We assessed tumor volumetry based on serial MR images, facial nerve function, hearing function, tinnitus, trigeminal symptoms, and vertigo, and compared them between treatment groups.

Results Surgery was more efficient for tumor control than for radiosurgery (p < 0.001). After radiosurgery, hearing and facial nerve functions remained initially stable. After surgery, there was clinical deterioration mainly for large tumors; for small tumors, deterioration was minimal, rendering functional results similar to GK radiosurgery. Furthermore, surgery alleviated symptoms like facial hypoesthesia, dizziness, and tinnitus more effectively than radiosurgery.

Conclusion In vestibular schwannoma treatment, radiosurgery is superior to surgery in preserving hearing and facial function. This difference is most evident for large tumors; in this group of patients, surgery is superior to GK radiosurgery in controlling tumor size, however. In small tumors, no significant difference was found between both methods in regard to hearing and facial function outcomes at long term.