Hypofractionated CyberKnife stereotactic radiosurgery for acoustic neuromas with and without association to neurofibromatosis Type 2.
CyberKnife stereotactic radiosurgery (CKSRS) has been proved effective in treating intra-cranial lesions. To treat acoustic neuroma (AN) patients with or without neurofibromatosis Type 2 (NF2) associations, the functional preservation of hearing, trigeminal nerve, and facial nerve are important. Twenty-one patients were treated with hypofractionated CKSRS. Fourteen non-NF2 and seven NF2 patients were enrolled. Cranial nerve function, audiograms, and magnetic resonance images (MRI) were monitored. Mean follow-up was 15 month. Tumors with volumes ranging from 0.13 to 24.8 cm3 (mean 5.4 cm3) were irradiated with the marginal dose 1800-2000 cGy/3 fractions. Tumors were treated with an 80 to 89% isodose line (mean 83%) and mean 97.9% tumor coverage. Two patients experienced hearing deterioration (16.7%) in the non-NF2 group, and 3 patients (50%) in the NF2 group. No facial or trigeminal dysfunction, brain stem toxicity, or cerebellar edema occurred. Tumor regression was seen in 9 patients (43%) and stable in 12 patients (57%). 100% tumor control rate was achieved. Hypofractionated CKSRS was not only effective in tumor control but also excellent in hearing preservation for non-NF2 AN. But for NF2 patients, although the tumor control was remarkable, hearing preservation was modest as in non-NF2 patients.
Ju
D T
DT
National Defense Medical Center, Department of Neurological Surgery, Tri-Service General Hospital, Taipei, Taiwan.
Lin
J W
JW
Lin
M S
MS
Lee
L M
LM
Tseng
H M
HM
Wei
C P
CP
Yen
C H
CH
Hung
C C
CC
Hung
K S
KS
Lin
C M
CM
Lin
T J
TJ
Chiu
W T
WT
Tsai
J T
JT
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016518:Neurofibromatosis 2 / Q000150:complications / Q000473:pathology / Q000601:surgery*; D009464:Neuroma, Acoustic / Q000150:complications / Q000473:pathology / Q000601:surgery*; D010525:Peripheral Nerves / Q000503:physiopathology; D016634:Radiosurgery / Q000379:methods*