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

Stereotactic radiosurgery (SRS) and resection are treatment options for patients with facial nerve schwannomas without mass effect.  This article evaluates outcomes of patients treated with SRS versus resection + SRS.  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.  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%,  = 0.04). Most of SRS (32/43, 74%) and resection + SRS (10/12, 83%) group patients reached a favorable combined endpoint following SRS (  = 0.52). Considering surgical associated side effects, only 2/10 patients of the resection + SRS group reached a favorable endpoint (  < 0.001). Patients of SRS group, who are > 34 years old (  = 0.02), have larger tumors (> 4 mL, 0.04), internal auditory canal (IAC) segment tumor involvement (  = 0.01) were more likely to reach an unfavorable endpoint. Resection + SRS group patients did not show such a difference.  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.