title: [Surgical management of vestibular schwannomas secondary to type 2 neurofibromatosis].
abstract: To evaluate the results of Gamma Knife radiosurgery treating vestibular schwannomas (VS) secondary to type 2 neurofibromatosis (NF2) we reviewed our clinical experience. Among the VS that have been treated between July 1992 and January 2002, we could analyze retrospectively the data of 50 VS from 37 patients. Fourteen patients had the mild phenotype while 23 were affected by the severe form. Before radiosurgery, one or two microsurgery attempts had been undertaken in 16 VS. Tumor Volume ranged from 120 to 14405 mm3 (mean: 3468 mm3) at the time of treatment; 12 tumors were Koos stade 4. Median clinical and radiological follow-up was 62 Months and ranged from 27 to 123 Months. The 5-Year and 10-Year actuarial survival rates without failure justifying tumor removal were 90 and 85% respectively. The 5-Year actuarial survival rate without hearing decreasing was 36% when selecting the cases of useful hearing (Gardner I & II) at the time of treatment. Severe phenotype (p=0.05) and dose (>12 Gy) delivered at the tumor margin (p=0.032) were correlated to hearing deterioration at univariated analysis. Permanent facial neuropathy occurred in 2%. Even though the level of tumor control and hearing preservation is not the same as for sporadic VS, these results show that Gamma Knife radiosurgery is a valuable alternative treatment for VS in NF2 patients. Future orientation of early proactive radiosurgical treatment of intracanalicular VS will probably improve these results.
authors.affiliation: Service de Neurochirurgie, Hôpital Sainte-Marguerite, Marseille. proche@mail.ap-hm.fr
authors.forename: P-H
authors.initials: PH
authors.lastname: Roche
authors.forename: S
authors.initials: S
authors.lastname: Robitail
authors.forename: J-M
authors.initials: JM
authors.lastname: Thomassin
authors.forename: W
authors.initials: W
authors.lastname: Pellet
authors.forename: J
authors.initials: J
authors.lastname: Régis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015897:Comorbidity; D005158:Facial Paralysis / Q000209:etiology; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000295:instrumentation; D008875:Middle Aged; D016518:Neurofibromatosis 2 / Q000453:epidemiology*; D009464:Neuroma, Acoustic / Q000453:epidemiology* / Q000601:surgery*; D016634:Radiosurgery / Q000295:instrumentation*; D012720:Severity of Illness Index; D013997:Time Factors