Can Trigeminal Schwannoma-Related Symptoms be Controlled With Gamma Knife Radiosurgery?

OBJECTIVE: The effectiveness of gamma knife radiosurgery (GKRS) for the management of trigeminal schwannomas (TS) has been established. Although GKRS has been shown to inhibit tumor growth, the effect of GKRS on the symptoms caused by TS has not been sufficiently studied. In this study, symptomatic changes following GKRS for the management of symptomatic TS were investigated using long-term follow-up results. METHODS: A retrospective analysis was performed on 32 patients with TS who underwent GKRS between May 1994 and December 2016. Clinical charts, radiographic results, and surgical records were reviewed. To evaluate whether symptoms improved after GKRS, patient demographics, GKRS profile, radiological tumor size change, and tumor location were analyzed. RESULTS: Tumor control after GKRS for symptomatic TS was 87%. The improvement rates for facial pain at 6, 12, and 24 months after GKRS were 46%, 72%, and 86%, respectively. For the same time intervals, facial hypesthesia improved by 12%, 46%, and 52%, respectively. Of the patients with diplopia, 17% had improved symptoms 12 months after GKRS, and 50% of the patients improved after 24 months. CONCLUSIONS: GKRS can be an effective treatment modality for TS tumor control and shows favorable results in improving TS-related symptom, especially facial pain.

Thirty-year clinical experience in gamma knife radiosurgery for trigeminal schwannomas.

We aimed to evaluate the radiographic and clinical outcomes after gamma knife radiosurgery (GKRS) for trigeminal schwannomas (TSs). A total of 87 patients who underwent GKRS for TSs between 1990 and 2020 were enrolled. The mean tumor volume was 4.3 cm3. The median prescribed dose for the margins of the tumor was 13 Gy. The median follow-up duration was 64.3 months (range 12.0-311.5 months). The overall local tumor control rate was 90%, and the symptom response rate was 93%. The response rate for each symptom was 88% for facial pain, 97% for facial sensory change, and 86% for cranial nerve deficits. Nineteen (22%) patients showed transient swelling, which had regressed at the time of the last follow-up. Cystic tumors were associated with transient swelling (p = 0.04). A tumor volume of < 2.7 cm3 was associated with local tumor control in univariable analysis. Transient swelling was associated with symptom control failure in both univariable and multivariable analyses (p = 0.04, odds ratio 14.538). GKRS is an effective treatment for TSs, both for local control and symptom control.

Safety and Efficacy of Hypofractionated Stereotactic Radiosurgery in Facial Nerve Schwannoma.

OBJECTIVE: In the current era of modern neurosurgery, the treatment strategies have been shifted to "nerve-preservation approaches" for achieving a higher facial and hearing function preservation rate following facial nerve tumors. We have conducted this novel report on determining the outcome of patients with facial nerve schwannomas (FNS) treated with hypofractionated stereotactic radiosurgery (hfSRS). PATIENTS: Retrospective chart review of a prospectively maintained database search was conducted. INTERVENTION: Patients who underwent hfSRS CyberKnife (Accuray Inc, Sunnyvale, CA, U.S.A.) for FNS were included. MAIN OUTCOME MEASURES: Outcomes consisted of tumor control, facial and hearing nerve function as graded by House-Brackmann and American Academy of Otolaryngology-Head and Neck Surgery recommendations, and adverse radiation effects. RESULTS: With an institutional board review approval, we retrospectively identified five patients with FNS (four intracranial [80%] and one extracranial [20%]) treated with hfSRS (2011-2019). Patients received definitive SRS in three patients (60.0%), whereas adjuvant to surgical resection in two patients (40.0%). A median tumor volume of 7.5 cm 3 (range, 1.5-19.6 cm 3 ) received a median prescription dose of 23.2 Gy (range, 21-25 Gy) administered in median of three fractions (range, three to five sessions). With a median radiographic follow-up of 31.4 months (range, 13.0-71.0 mo) and clinical follow-up of 32.6 months (range, 15.1-72.0 mo), the local tumor control was 100.0%. At the last clinical follow-up, the facial nerve function improved or remained unchanged House-Brackmann I-II in 80.0% of the patients, whereas the hearing nerve function improved or remained stable in 100.0% of the patients. Temporary clinical toxicity was observed in three patients (60.0%), which resolved. None of the patients developed adverse radiation effect. CONCLUSION: From our case series, hfSRS in FNS seems to be safe and efficacious in terms of local tumor control, and improved facial and hearing nerve function.

Gamma knife radiosurgery for trigeminal schwannomas: A systematic review and meta-analysis.

BACKGROUND: Gamma knife radiosurgery (GKRS) has been deemed as the gold standard stereotactic radiosurgery (SRS) mode for the treatment of intracranial tumors, cerebrovascular diseases and brain functional diseases. Our study was aimed to systematically evaluate the efficacy, safety, and complications of gamma knife radiosurgery for trigeminal schwannomas. METHOD: We performed a systematic review and meta-analysis to analyze the clinical outcomes of patients with trigeminal schwannomas treated primarily or adjunctly with GKRS. We searched two databases, Pubmed and Embase, for studies published before January 1, 2021, using GKRS for trigeminal schwannomas. Studies reporting treatment of other schwannomas, or other forms of SRS such as linear accelerator and Cyberknife were excluded to reduce its heterogeneity. RESULTS: Our search achieved 351 studies, of which 35 were assessed for full-text eligibility. 19 studies were included in the meta-analysis. 456 of 504 patients (0.94, 95% CI 0.91-0.96, I2 = 3.02%, p < 0.01) from 18 studies had local control, and 278 of 489 patients (0.63, 95%CI 0.48-0.78, I2 = 88.75%, p < 0.01) from 16 studies experienced tumor regression or disappearance. 231 of 499 patients (0.50, 95% CI 0.37-0.62; I2 = 83.89%, P < 0.01) from 17 studies had clinical symptoms improved. There was no significant difference in tumor control between those treated with GKRS as either primary treatment or adjuvant to surgery(p = 0.390). CONCLUSION: GKRS is an efficacious primary and adjuvant method of treating trigeminal schwannomas, with reliable tumor control rates. Randomized controlled trials are needed to further and comprehensively evaluate the benefit-to-risk ratio of gamma knife radiosurgery.

Stereotactic radiosurgery for hypoglossal schwannoma.

Hypoglossal schwannomas (HS) are extremely rare neoplasms. Surgical resection has historically been the treatment of choice but carries a significant risk of postoperative neurological deficits and mortality. Stereotactic radiosurgery (SRS) is a minimally invasive approach that may afford long-term tumour growth. However, literature to determine the safety and effectiveness of SRS in the treatment of HS is scarce. We report on a patient who presented with progressive headache and dysphagia as well as tongue deviation to the left, due to a space-occupying lesion, consistent on brain MRI with a left HS. Primary SRS using a prescription dose of 12 Gy in a single fraction was used to treat the tumour without complications. By last follow-up, the tumour regressed, and the patient's symptoms improved. Our case shows that radiosurgery can be safe and effective for the management of HS.

Stereotactic radiosurgery for the treatment of hypoglossal schwannoma: a multi-institutional retrospective study.

BACKGROUND: Surgical removal has been performed as the first line treatment for symptomatic or enlarging hypoglossal schwannomas (HS). Stereotactic radiosurgery (SRS) offers a minimally invasive approach that may afford long-term tumor control for patients with HS particularly those who refuse or are unfit for surgery. This study evaluates outcomes after SRS performed for both newly diagnosed and residual tumors after incomplete resection. METHODS: This retrospective, multi-institutional study involved patients treated with adjuvant or primary SRS for HS. The study end-points included local tumor response, clinical outcomes, and procedure-related complications. All the patients had Gamma Knife SRS. RESULTS: The cohort included 12 patients (five females), median age at SRS 49.5 years (range, 37-76)]. The median tumor target volume was 5.9 cm3 (range, 0.7-27.23). At median imaging follow-up of 37 months (range, 6-153), tumor control was achieved in 11 patients. Tumor enlargement that was managed with surgical resection was noted at the 6-month follow-up in one patient. At median clinical follow-up of 30.5 months (range, 6-157), stability, or improvement of all pre-SRS signs and symptoms was noted in nine patients. Two patients experienced worsening of at least one pre-existing symptoms or sign. New-onset trapezius weakness was noted in one patient and tongue atrophy in two patients. CONCLUSION: Single-fraction SRS appears to be a safe and effective upfront and adjuvant treatment option for HS. SRS may be recommended as an alternative to surgery for patients presenting with HS or as an adjuvant treatment following subtotal resection and at HS recurrence.

Radiation Dose Rate, Biologically Effective Dose, and Tumor Characteristics on Local Control and Toxicity After Radiosurgery for Acoustic Neuromas.

OBJECTIVE: To evaluate the relationships between calibration dose rate, calculated biologically effective dose (BED), and clinical factors and tumor control after stereotactic radiosurgery (SRS) for acoustic neuroma. METHODS: We performed a retrospective study of all patients with acoustic neuromas treated with frame-based cobalt-60 SRS at a single institution between 2005 and 2019. The calibration dose rate and cobalt-60 half-life were used to calculate the nominal dose rate during treatment. An SRS-specific monoexponential model accounting for treatment time per lesion was used to estimate BED. RESULTS: The study included 607 patients with 612 acoustic neuromas. Median follow-up was 5.0 years. There was no association between dose rate or BED with local failure (LF), radiologic edema, or symptomatic edema. Cystic tumors (adjusted hazard ratio 0.26, P = 0.028) were associated with lower LF, while use of SRS as salvage treatment for growing tumors (adjusted hazard ratio 4.9, P < 0.0001) was associated with higher LF. LF occurred more frequently in larger-diameter tumors, while radiologic or symptomatic edema occurred more frequently in larger-volume tumors. CONCLUSIONS: Radiosurgery dose rate and BED were not associated with tumor control or radiologic or symptomatic edema. Salvage SRS and larger tumors were associated with a higher LF rate, while cystic tumors were associated with a lower LF rate. Patients with larger tumors should be counseled appropriately about potential side effects and when to seek follow-up care.

Trigeminal Ophthalmic Branch Schwannoma: Case Report and Literature Review

Schwannomas are the fourth most common primary neoplasms affecting the brain and cranial nerves. Central lesions commonly arise from sensory nerve roots, and a common intracranial site is the vestibular branch of the 8th nerve (>85%). We present the case report of a patient who has a schwannoma extending from the pterygopalatine fossa to the orbit, complaining about facial pain in the trajectory of the trigeminal ophthalmic branch. Schwannomas represent 1 to 2% of all neoplasms of the orbit, and trigeminal schwannomas are extremely rare, accounting for less than 0.5% of all intracranial tumors.

Anterior Petrosal Approach for Enlarging Previously Radiated Recurrent Trigeminal Schwannoma: 2-Dimensional Operative Video.

Trigeminal nerve schwannomas (TNSs) are rare lesions that typically present with symptoms of trigeminal neuropathy or other cranial nerve palsies. These lesions classically have a dumbbell shape, with an anterior component within Meckel's cave and posterior component extending into the posterior fossa through the porus trigeminus. Surgical resection of TNSs can often be achieved via an extradural subtemporal approach to Meckel's cave without an anterior petrousectomy, even for tumors with a significant posterior fossa component, as the tumor often erodes a portion of the petrous apex.1 We present the case of a 53-yr-old female presenting to our institution with complete trigeminal neuropathy secondary to a right-sided, previously resected and radiated TNS. Serial imaging demonstrated an interval growth of significant residual tumor despite multiple adjuvant therapies, and, thus, the patient was recommended to undergo additional surgical resection. The lesion was approached through a right-sided subtemporal approach to Meckel's cave,2 with a plan to utilize an anterior petrousectomy only if difficulty resecting the posterior fossa component of the tumor was encountered. Intraoperatively, the posterior fossa component was found to be densely adherent to the adjacent brainstem, likely secondary to prior surgery and radiation therapy, and, thus, an anterior petrousectomy was performed. Postoperatively, the patient had stable trigeminal neuropathy without any new neurological deficits and a magnetic resonance imaging (MRI) confirmed a gross total resection. In the accompanying video, we hope to demonstrate the steps and nuances of both the subtemporal approach to accessing Meckel's cave and anterior petrousectomy when employed for the resection of TNSs. The patient in question provided formal consent for the making of this video.

[Progress in the surgical treatment of trigeminal schwannoma].

Trigeminal schwannomas(TSs) is the second most common intracranial schwannomas next to acoustic neuroma. These uncommon, slow-growing tumors, which prove to originated from Schwann cells of the fifth brain nerve, can achieve their development into various compartments.Previous to the era of microsurgery, the total tumor resection rate was low, and the postoperative neurological function was seriously damaged.With the development of microsurgery and skull base approach, the microsurgery effect of TSs has been improved. Besides, neuroendoscopy is also used in the operation of some types of trigeminal schwannomas. Radiation therapy can be performed to control tumor growth for the patients who cannot tolerate surgery, have small tumor volume, have residual tumor tissue or relapse.

Parasellar Meningiomas.

Parasellar spaces remain particularly singular, comprising the most important neurovascular structures such as the internal carotid artery and optic, oculomotor, and trigeminal nerves. Meningiomas are one of the most frequent tumors arising from parasellar spaces. In this location, meningiomas remain mostly benign tumors with WHO grade I and a meningothelial subtype. Progestin intake should be investigated and leads mostly to conservative strategies. In the case of benign nonsymptomatic tumors, observation should be proposed. Tumor growth will lead to the proposition of surgery or radiosurgery. In the case of an uncertain diagnosis and an aggressive pattern, a precise diagnosis is required. For cavernous sinus and Meckel's cave lesions, complete removal is rarely considered, leading to the proposition of an endoscopic endonasal or transcranial biopsy. Optic nerve decompression could also be proposed via these approaches. A case-by-case discussion about the best approach is recommended. A transcranial approach remains necessary for tumor removal in most cases. Vascular injury could lead to severe complications. Cerebrospinal fluid leakage, meningitis, venous sacrifice, visual impairment, and cranial nerve palsies are more frequent complications. Pituitary dysfunctions are rare in preoperative assessment and in postoperative follow-up but should be assessed in the case of meningiomas located close to the pituitary axis. Long-term follow-up is required given the frequent incomplete tumor removal and the risk of delayed recurrence. Radiosurgery is relevant for small and well-limited meningiomas or intra-cavernous sinus postoperative residue, whereas radiation therapy and proton beam therapy are indicated for large, extended, nonoperable meningiomas. The place of the peptide receptor radionuclide therapyneeds to be defined. Targeted therapy should be considered in rare, recurrent, and aggressive parasellar meningiomas.

Hypofractionated Robotic Stereotactic Radiosurgery for Vagal Paragangliomas: A Novel Treatment Strategy for Cranial Nerve Preservation.

OBJECTIVE: To provide the first description of hypofractionated stereotactic radiosurgery (SRS) and evaluate tumor control and safety for vagal paragangliomas (VPs), which begin at the skull base but often have significant extracranial extension. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary-referral neurotology and neurosurgery practice. SUBJECTS AND METHODS: Five VPs in 4 patients (all male, ages 15-56 years) underwent SRS between 2010 and 2018. Outcome measures included tumor dimensions on serial imaging, cranial nerve function, and radiation side effects. RESULTS: CyberKnife hypofractionated SRS was performed. The prescription dose was 24 or 27 Gy (maximum dose 33.4 Gy; range, 29.3-35.5 Gy) delivered in 3 equal fractions. The mean isodose line was 79% (range, 76%-82%). Four VPs were treated primarily, and 1 tumor underwent SRS to treat regrowth 2 years after microsurgical subtotal resection via the modified infratemporal fossa approach. The treatment volume ranged from 8.81 to 86.3 cm3 (mean, 35.7 cm3). All demonstrated stable size (n = 3) or regression (n = 2) at last follow-up, 63 to 85 months after SRS (mean, 76 months). One patient had stable premorbid vocal fold paralysis from a prior ipsilateral glomus jugulare tumor resection. All others demonstrated normal vagal function following SRS. Treatment-related side effects, including dysgeusia (n = 1), mucositis (n = 1), and neck soft-tissue edema (n = 2), were self-limited. CONCLUSIONS: Hypofractionated SRS appears to be both safe and effective for treating VPs, including large-volume and predominantly extracranial tumors, while preserving vagal function. SRS should be considered as a cranial nerve preservation option, especially in settings of contralateral lower cranial nerve deficits or in those with multiple paragangliomas risking both vagal nerves.

Facial Nerve Schwannoma Complicated by Acute Hemorrhage After Treatment with Stereotactic Radiosurgery.

BACKGROUND: Facial nerve schwannomas (FNSs) are rare benign tumors that arise from Schwann cells of the facial nerve. FNSs are similar to vestibular schwannomas in many aspects, yet their infiltrative nature into the facial nerve fascicles warrants a more conservative management approach. In the last decade, stereotactic radiosurgery (SRS) has shown promise in stabilizing or shrinking FNSs. CASE DESCRIPTION: A 71-year-old woman presented with mild facial paresis. Tumor growth after a period of watchful waiting warranted treatment with SRS, which was complicated by an acute posterior fossa hemorrhage and brainstem compression, necessitating microsurgical hematoma evacuation, tumor resection, and facial nerve substitution. CONCLUSIONS: SRS has led to better facial nerve function and outcomes and is currently considered a reasonable alternative to microsurgical resection in patients with FNSs. This is the first report to our knowledge of an acute, life-threatening hemorrhage after SRS in a patient with FNS.

Outcomes following proton therapy for Ewing sarcoma of the cranium and skull base.

PURPOSE: Despite the dosimetric advantages of proton therapy, little data exist on patients who receive proton therapy for Ewing sarcoma of the cranium and skull base. This study reports local disease control and toxicity in such patients. MATERIALS/METHODS: We reviewed 25 patients (≤21 years old) with nonmetastatic Ewing sarcoma of the cranium and skull base treated between 2008 and 2018. Treatment toxicity was graded per the Common Terminology Criteria for Adverse Events v4.0. The Kaplan-Meier product limit method provided estimates of disease control and survival. RESULTS: Median patient age was 5.9 years (range, 1-21.7). Tumor subsites included the skull base (48%), non-skull-base calvarial bones (28%), paranasal sinuses (20%), and nasal cavity (4%). All patients underwent multiagent alkylator- and anthracycline-based chemotherapy; 16% underwent gross total resection (GTR) before radiation. Clinical target volume (CTV) 1 received 45 GyRBE and CTV2 received 50.4 GyRBE following GTR or 54-55.8 GyRBE following biopsy or subtotal resection. Median follow-up was 3.7 years (range, 0.26-8.3); no patients were lost. The 4-year local control, disease-free survival, and overall survival rates were 96%, 86%, and 92%, respectively. Two patients experienced in-field recurrences. One patient experienced bilateral conductive hearing loss requiring aids, two patients developed intracranial vasculopathy, and 6 patients required hormone replacement therapy for neuroendocrine deficits. None developed a secondary malignancy. CONCLUSION: Proton therapy is associated with a favorable therapeutic ratio in children with large Ewing tumors of the cranium and skull base. Despite its high conformality, we observed excellent local control and no marginal recurrences. Treatment dosimetry predicts limited long-term neurocognitive and neuroendocrine side effects.

Oculomotor Schwannomas: A Systematic Review and Report of Two Pediatric Cases Treated with Fractionated Cyberknife Stereotactic Radiotherapy.

OBJECTIVE: Pediatric oculomotor nerve schwannomas are rare and challenging lesions due to the high morbidity associated with surgical intervention and their proximity to critical structures limiting the opportunity for stereotactic radiosurgery. We aim to report and review the novel use of fractionated Cyberknife (Accuray, Inc., Sunnyvale, California, USA) stereotactic radiotherapy in pediatric patients with oculomotor schwannomas. METHODS: A systematic review of PubMed, Embase, and Cochrane was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two patients, ages 8 and 10 years, with tumor volumes of 0.1 cm3 and 0.2 cm3, respectively, were treated with fractionated Cyberknife radiotherapy at our institution. A total dose of 45-50 Gy was administered over 25 fractions (1.8-2.0 Gy per fraction) to the 82%-84% isodose line. Serial magnetic resonance imaging was obtained for long-term follow-up (56-58 months). RESULTS: We found 14 articles published between 1982 and 2018 that reported a total of 18 pediatric patients with intracranial oculomotor schwannomas. No previously described cases of pediatric intracranial oculomotor schwannomas were treated with radiation therapy. In both of our patients, radiographic tumor control was achieved at a mean follow-up of 57 months, with 1 patient displaying a decrease in tumor volume. Neither patient exhibited any worsening of their presenting symptoms, nor did either patient develop any new neurocognitive deficits following treatment. CONCLUSIONS: Fractionated Cyberknife radiotherapy is an effective and well-tolerated treatment option for intracranial oculomotor nerve schwannomas with excellent tumor control rates, similar to surgical and radiosurgical techniques, while sparing critical surrounding structures.

Evaluation and Management of Facial Nerve Schwannoma.

Facial nerve schwannomas are benign peripheral nerve sheath tumors that arise from Schwann cells, and most commonly present with facial paresis and/or hearing loss. Computed tomography and MRI are critical to diagnosis. Management decisions are based on tumor size, facial function, and hearing status. Observation is usually the best option in patients with good facial function. For patients with poor facial function, the authors favor surgical resection with facial reanimation. There is growing evidence to support radiation treatment in patients with progressively worsening moderate facial paresis and growing tumors.

Stereotactic Radiosurgery for Trigeminal Schwannomas: A 28-Year Single-Center Experience and Review of the Literature.

OBJECTIVE: To assess outcomes and complications of stereotactic radiosurgery treatment for trigeminal schwannoma (TS). METHODS: A retrospective analysis was performed to describe the presentation and outcomes of patients undergoing Gamma Knife radiosurgery (GKRS) for TS. Clinical, radiographic, and stereotactic radiosurgery dose plans were reviewed. Descriptive statistics and univariate analysis were performed to identify factors associated with poor tumor control. RESULTS: A total of 22 patients with TS were treated with GKRS between 1990 and 2018. One patient had a history of neurofibromatosis type II. Of the study population, 81% underwent GKRS as a first-line treatment. The average tumor volume was 3.3 cm3 and the average margin treatment dose was 14.1 Gy. The median clinical and radiographic follow-up period were 18.5 and 27 months, respectively. Tumor control was achieved in 17 patients (77.3%). Symptomatic improvement was noted in 8 patients (42.1%). Tumor expansion was observed in 7 patients (31.8%) and was associated with poor tumor control at last follow-up (P < 0.05). Patients who developed transient tumor expansion had higher margin doses (14.9 ± 1.1 Gy) compared with patients who did not have expansion (13.6 ± 1.3 Gyk P < 0.05). CONCLUSIONS: GKRS provides effective control for most TS. Increased margin doses are associated with tumor expansion, which was a poor prognostic event associated with progression and clinical decline. Based on these results, combined with analysis of available data from other series of TS treated with GKRS, we believe that margin dose between 13 and 14 Gy offers a high probability of tumor control, yet minimizing risk of adverse radiation effects.

High dose hypofractionated frameless volumetric modulated arc radiotherapy is a feasible method for treating canine trigeminal nerve sheath tumors.

The aim of this prospective pilot study was to evaluate the feasibility and effectiveness of curative intent high dose hypofractionated frameless volumetric modulated arc radiotherapy for treatment of canine trigeminal peripheral nerve sheath tumors. Client-owned dogs with a presumptive imaging-based diagnosis of trigeminal peripheral nerve sheath tumor were recruited for the study during the period of February 2010 to December 2013. Seven dogs were enrolled and treated with high dose hypofractionated volumetric modulated arc radiotherapy delivered by a 6 MV linear accelerator equipped with a micro-multileaf beam collimator. The plans were computed using a Monte Carlo algorithm with a prescription dose of 37 Gy delivered in five fractions on alternate days. Overall survival was estimated using a Kaplan-Meier curve analysis. Magnetic resonance imaging (MRI) follow-up examinations revealed complete response in one dog, partial response in four dogs, and stable disease in two dogs. Median overall survival was 952 days with a 95% confidence interval of 543-1361 days. Volumetric modulated arc radiotherapy was demonstrated to be feasible and effective for trigeminal peripheral nerve sheath tumor treatment in this sample of dogs. The technique required few sedations and spared organs at risk. Even though larger studies are required, these preliminary results supported the use of high dose hypofractionated volumetric modulated arc radiotherapy as an alternative to other treatment modalities.

Gamma Knife Stereotactic Radiosurgery for Nonvestibular Cranial Nerve Schwannomas.

BACKGROUND: Nonvestibular cranial schwannomas represent a rare type of benign intracranial tumor. Few studies have evaluated the use of stereotactic radiosurgery (SRS) as a primary management option for these lesions. We performed a retrospective review of our institution's experience focusing on efficacy with regard to tumor control and clinical symptom stabilization as well as treatment safety. METHODS: Patients were included if they underwent at least 1 SRS procedure for a nonvestibular schwannoma and had at least 6 months of available imaging follow-up. Demographic, SRS dose planning, clinical, and imaging data were collected from chart reviews of treated patients. χ2 and Kaplan-Meier analyses were performed. RESULTS: Between 2004 and 2016, 35 schwannomas were treated in 34 patients. Median follow-up was 48 months. Median age at time of treatment was 51 years. Three patients had neurofibromatosis 2. Schwannoma location was trigeminal (57%), facial (20%), jugular foramen (14%), abducens (6%), and trochlear (3%). Median margin dose delivered was 13 Gy. The 5-year and 10-year tumor control rates were 94.4% and 88.5%, respectively. Presenting clinical symptoms stabilized or improved in 79% of cases after radiosurgery, and new or worsening symptoms were seen in 21%. CONCLUSIONS: SRS is a safe and effective modality for treatment of nonvestibular cranial nerve schwannomas.