Fractionated Stereotactic Radiotherapy for Facial Nerve Neuroma: The First Reported Case
Departments of 1Neurosurgery and 2Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN
Facial nerve neuromas are extremely rare, and are often mistaken for acoustic neuromas when located near the vestibular nerve. Usually presenting with facial weakness and hearing loss, facial nerve neuromas of the cerebellopontine angle have commonly been managed by surgery. We present the first reported case of a facial nerve neuroma treated with fractionated stereotactic radiotherapy (FSRT).
The patient was a 40-year-old woman who presented with tinnitus, dizziness, and decreased hearing that was associated with a right intracanalicular mass on magnetic resonance imaging. She underwent a middle fossa craniotomy only to reveal a facial nerve tumor rather than an acoustic neuroma that was not resected due to the high risk of facial paralysis. Following surgery, her facial function worsened and was associated with tumor enlargement on MRI. She was referred for FSRT and received 54 Gy in daily 1.8-Gy fractions with a prescription isodose line of 90%.
Three months after treatment she had no worsening of her pre-treatment symptoms, and at one-year follow-up, she experienced facial weakness improvement accompanied by an absence of tumor growth on MRI. These clinical and imaging findings persisted at 48 months of follow-up.
In the first report of a facial nerve neuroma treated with fractionated stereotactic radiotherapy, this treatment resulted in excellent long-term (4 year) tumor control with improvement of pre-treatment symptomatology and absence of morbidity. This report demonstrates the potential for using FSRT to treat facial nerve neuromas of the cerebellopontine angle that could otherwise be associated with significant operative morbidity.
Fractionated Stereotactic Radiotherapy, Facial Nerve Neuroma, Cerebellopontine Angle, Tumor Control