Gamma Knife Radiosurgery for Facial nerve schwannomasKeywords: facial nerve function, schwannoma, cranial nerve, gamma knife, outcomeInteractive Manuscript
Ask Questions of this Manuscript:
What is the background behind your study?
Surgical resection of facial nerve schwannomas (FNS) results a high risk of severe facial nerve palsy.
What is the purpose of your study?
Our purpose was to evaluate functional preservation and tumor control after Gamma knife radiosurgery (GKRS) .
Describe your patient group.
Between January 2002 and May 2011, 6 patients with FNS were treated by GKRS and followed in our institute.
Describe what you did.
Diagnosis of facial nerve schwannoma was based on MRI. Clinical evaluation on House-Brackmann grade. Classified of two types tumor location for evaluate facial and chocleovestibular function after GKRS.(Type I: tumor develops in geniculate ganglion to tympanic, vertical ,mastoid segment of the facila canal, Type II; tumor develops in the middle fossa or internal auditory canal, cerebello pontine angle cistern.) Three patients were type I and 3 patients were type II .
Describe your main findings.
Mean follow up periods were 37 months ( 6-72 months).No patients had a previous resection. The radiosurgery dose was 11 or 12 Gy at 50% isodose. Three tumors had regressed and 3 were unchanged in size at latest MRI. Transient facial nerve worsening were observed 2 patients in type I tumor. All patients maintained their hearing after GKRS.
Describe the main limitation of this study.
This was a retrospective study.
Describe your main conclusion.
Although longer follow up period is necessary, GKRS is shown to be a safe and effective treatment of FNS.
Describe the importance of your findings and how they can be used by others.
Treatment decisions should be based on initial facial function, tumor volume growth
rate, and informed patient consent especially for type I schwannomas.
Surgical resection of facial nerve schwannomas (FNS) results a high risk of severe facial nerve palsy.
Our purpose was to evaluate functional preservation and tumor control after Gamma knife radiosurgery (GKRS) .
Between January 2002 and May 2011, 6 patients with FNS were treated by GKRS and followed in our institute.
Diagnosis of facial nerve schwannoma was based on MRI. Clinical evaluation on House-Brackmann grade. Classified of two types tumor location for evaluate facial and chocleovestibular function after GKRS.(Type I: tumor develops in geniculate ganglion to tympanic, vertical ,mastoid segment of the facila canal, Type II; tumor develops in the middle fossa or internal auditory canal, cerebello pontine angle cistern.) Three patients were type I and 3 patients were type II .
Mean follow up periods were 37 months ( 6-72 months).No patients had a previous resection. The radiosurgery dose was 11 or 12 Gy at 50% isodose. Three tumors had regressed and 3 were unchanged in size at latest MRI. Transient facial nerve worsening were observed 2 patients in type I tumor. All patients maintained their hearing after GKRS.
This was a retrospective study.
Although longer follow up period is necessary, GKRS is shown to be a safe and effective treatment of FNS.
Treatment decisions should be based on initial facial function, tumor volume growth
rate, and informed patient consent especially for type I schwannomas.
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