Gamma knife radiosurgery for trigeminal schwannomas.
BACKGROUND
Trigeminal schwannomas are uncommon tumors that may be microsurgically removed in selected cases, albeit with significant risk for new neurological morbidity. We evaluated the role of stereotactic radiosurgery as an alternative for patients with newly diagnosed or residual trigeminal schwannomas.


METHODS
The records of 23 patients who underwent radiosurgery for trigeminal schwannoma were reviewed. The most frequent presenting symptoms were facial numbness (11 patients), diplopia (6 patients), and facial pain (3 patients). One patient presented with partial complex seizures as the first symptom. Twelve patients had undergone one or more prior resections. Eleven underwent radiosurgery on the basis of imaging diagnosis only. The mean tumor volume was 4.5 mL (range 0.46-11.2 cc). Radiosurgery was performed using a median marginal dose of 15 Gy (range, 13-20 Gy).


RESULTS
At a median imaging follow-up of 40 months (range, 12-146), 20 of 22 evaluable patients (91%) had tumor growth control (regression in 15 and no further tumor growth in 5). One 80-year-old patient died of unrelated cause 4 months after radiosurgery. Two patients with enlarged tumors were treated effectively with repeat radiosurgery. Twelve of 23 patients (52%) reported improvement and 9 (39%) had no change in their symptoms. Two patients noted new neurological complaints (transient facial weakness in 1 patient and worsening of the preradiosurgery facial numbness in another patient).


CONCLUSIONS
Radiosurgery is an effective minimally invasive management option for patients with residual or newly diagnosed trigeminal schwannomas.
Nettel
Barbara
B
Department of Neurological Surgery, The University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Niranjan
Ajay
A
Martin
Juan J
JJ
Koebbe
Christopher J
CJ
Kondziolka
Douglas
D
Flickinger
John C
JC
Lunsford
L Dade
LD
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D010146:Pain / Q000209:etiology / Q000601:surgery; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications; D016634:Radiosurgery / Q000379:methods*; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D020433:Trigeminal Nerve Diseases / Q000473:pathology / Q000601:surgery*