Long-term results of Leksell gamma knife surgery for trigeminal schwannomas.
OBJECTIVE
The authors evaluated the long-term efficacy of gamma knife surgery (GKS) in patients with trigeminal schwannomas.


METHODS
Fifty-six patients, 31 women and 25 men (mean age 42 years), underwent GKS for trigeminal schwannomas. Fourteen had previously undergone surgery, and GKS was the primary treatment in the remaining 42 patients. The mean target volume was 8.7 cm3 (range 0.8-33 cm3); the mean maximum dose was 27 Gy (range 20-40 Gy); the mean tumor margin dose was 13.3 Gy (range 10-15 Gy); and the mean follow-up period was 68 months (range 27-114 months). Disappearance of the tumor occurred in seven patients. An obvious decrease in tumor volume was observed in 41 patients, four tumors remained unchanged, and four tumors progressed at 5, 26, 30, and 60 months, respectively. One patient with disease progression died of tumor progression at 36 months after GKS. The tumor growth control rate in this group was 93% (52 of 56 cases). Mild numbness or diplopia was relieved completely in 14 patients. Improvement of other neurological deficits was demonstrated in 25 patients. Trigeminal nerve dysfunction was either unchanged or slightly worse in 13 patients after GKS. Four patients experienced mild symptom deterioration related to tumor progression.


CONCLUSIONS
Radiosurgery proved to be an effective treatment for small- and medium-sized trigeminal schwannomas. Some larger tumors are also suitable for radiosurgery if there is no significant brainstem compression.
Pan
Li
L
Department of Neurosurgery and Radiology, Huashan Hospital and Shanghai Gamma Knife Hospital, Fudan University, Shanghai Neurosurgical Center, Shanghai, China.
Wang
En-Min
EM
Zhang
Nan
N
Zhou
Liang-Fu
LF
Wang
Bing-Jiang
BJ
Dong
Ya-Fei
YF
Dai
Jia-Zhong
JZ
Cai
Pei-Wu
PW
D020434:Abducens Nerve Diseases / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000209:etiology; D002648:Child; D003390:Cranial Nerve Neoplasms / Q000473:pathology / Q000601:surgery*; D003560:Cysts / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000150:complications; D016634:Radiosurgery / Q000295:instrumentation*; D013995:Time; D014276:Trigeminal Nerve / Q000473:pathology / Q000601:surgery*