Facial Nerve Schwannoma Treatment with Stereotactic Radiosurgery (SRS) versus Resection followed by SRS: Outcomes and a Management Protocol

Sam Dayawansa; Chloe Dumot; Georgios Mantziaris; Gautam U. Mehta; Gregory P. Lekovic; Douglas Kondziolka; David Mathieu; Wael A. Reda; Roman Liscak; Lee Cheng-chia; Anthony M. Kaufmann; Gene Barnet; Daniel M. Trifiletti; L Dade Lunsford; Jason Sheehan

doi:10.1055/a-1990-2861

Journal of Neurological Surgery Part B: Skull Base, Table of Contents

J Neurol Surg B Skull Base 2024; 85(01): 075-080
DOI: 10.1055/a-1990-2861

Original Article

Facial Nerve Schwannoma Treatment with Stereotactic Radiosurgery (SRS) versus Resection followed by SRS: Outcomes and a Management Protocol

Authors

Sam Dayawansa

¹Department of Neurosurgery, University of Virginia Gamma Knife Surgery Center, Charlottesville, Virginia, United States
Chloe Dumot

²Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, United States
Georgios Mantziaris

²Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, United States
Gautam U. Mehta

³Department of Neurological Surgery, House Ear Institute, Los Angeles, California, United States

⁴Department of Neurological Surgery, Charlottesville, Virginia, United States
Gregory P. Lekovic

³Department of Neurological Surgery, House Ear Institute, Los Angeles, California, United States

⁵Department of Neurosurgery, House Clinic, Los Angeles, California, United States
Douglas Kondziolka

⁶Department of Neurosurgery, New York University Medical Center, New York, New York, United States
David Mathieu

⁷Department of Neurosurgery, University of Sherbrooke, Sherbrooke, Quebec, Canada
Wael A. Reda

⁸Gamma Knife Center Cairo, Nasser Institute Hospital, Cairo, Egypt

⁹Department of Neurosurgery, Ain Shams University, Cairo, Egypt
Roman Liscak

¹⁰Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic
Lee Cheng-chia

¹¹Department of Neurosurgery, Taipei Veteran General Hospital, Taipei, Taiwan

¹²Department of Neurosurgery, National Yang-Ming University, Hsinchu, Taiwan
Anthony M. Kaufmann

¹³Univ Manitoba, Winnipeg, Manitoba, Canada
Gene Barnet

¹⁴Department of Neuro Oncology, Cleveland Clinic, Cleveland, Ohio, United States
Daniel M. Trifiletti

¹⁵Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida, United States
L Dade Lunsford

¹⁶Department of Neurosurgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
Jason Sheehan

²Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, United States

Abstract

Background Stereotactic radiosurgery (SRS) and resection are treatment options for patients with facial nerve schwannomas without mass effect.

Objective This article evaluates outcomes of patients treated with SRS versus resection + SRS.

Method We retrospectively compared 43 patients treated with SRS to 12 patients treated with resection + SRS. The primary study outcome was unfavorable combined endpoint, defined as worsening or new clinical symptoms, and/or tumor radiological progression. SRS (38.81 ± 5.3) and resection + SRS (67.14 ± 11.8) groups had similar clinical follow-ups.

Results At the time of SRS, the tumor volumes of SRS (mean ± standard error; 1.83 ± 0.35 mL) and resection + SRS (2.51 ± 0.75 mL) groups were similar. SRS (12.15 ± 0.08 Gy) and resection + SRS (12.16 ± 0.14 Gy) groups received similar radiation doses. SRS group (42/43, 98%) had better local tumor control than the resection + SRS group (10/12, 83%, p = 0.04). Most of SRS (32/43, 74%) and resection + SRS (10/12, 83%) group patients reached a favorable combined endpoint following SRS (p = 0.52). Considering surgical associated side effects, only 2/10 patients of the resection + SRS group reached a favorable endpoint (p < 0.001).

Patients of SRS group, who are > 34 years old (p = 0.02), have larger tumors (> 4 mL, 0.04), internal auditory canal (IAC) segment tumor involvement (p = 0.01) were more likely to reach an unfavorable endpoint. Resection + SRS group patients did not show such a difference.

Conclusion While resection is still needed for larger tumors, SRS offers better clinical and radiological outcomes compared to resection followed by SRS for facial schwannomas. Younger age, smaller tumors, and non-IAC situated tumors are factors that portend a favorable outcome.

Keywords

facial nerve - schwannoma - stereotactic radiosurgery - internal auditory canal

Full Text

References

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