Unilateral Multifocal Inner Ear and Internal Auditory Canal or Cerebellopontine Angle Cochleovestibular Schwannomas-Genetic Analysis and Management by Surgical Resection and Cochlear Implantation.

OBJECTIVE: To describe the genetic characteristics and the management of two very rare cases of unilateral multifocal inner ear and internal auditory canal or cerebellopontine angle cochleovestibular schwannomas not being associated to full neurofibromatosis type 2-related schwannomatosis. PATIENTS: In a 29-year-old man and a 55-year-old woman with single-sided deafness multifocal unilateral cochleovestibular schwannomas were surgically resected, and hearing was rehabilitated with a cochlear implant (CI). Unaffected tissue was analyzed using next generation sequencing of the NF2 gene. Tumor tissue was analyzed using a 340-parallel sequencing gene panel. MAIN OUTCOME MEASURES: Mutations in the NF2 gene, word recognition score for monosyllables at 65 dB SPL (WRS 65 ) with CI. RESULTS: No disease-causing mutation was detected in the examined sequences in blood leucokytes. All tumor samples revealed, among others, somatic pathogenic NF2 mutations. While the anatomically separate tumors in case 1 were likely molecular identical, the tumors in case 2 showed different genetic patterns. WRS 65 was 55% at 6 years of follow-up and 60% at 4.5 years of follow-up, respectively. CONCLUSIONS: The occurrence of multifocal unilateral cochleovestibular schwannomas without pathogenic variants in NF2 in non-affected blood leucocytes can be associated with mosaic NF2 -related schwannomatosis (case 1), or with likely sporadic mutations (case 2) and may be overlooked due to their extreme rarity. Although challenging, successful hearing rehabilitation could be achieved through surgical resection of the tumors and cochlear implantation.

[To the origins of surgery for acoustic neuromas]. / K istokam khirurgii nevrinom slukhovogo nerva.

Acoustic neuroma is one of the most common tumors of the posterior cranial fossa. Its removal is always a challenge for the neurosurgeon and the patient. The history of surgery for acoustic neuromas is inextricably linked with the history of neurosurgery in general. The modern surgical community must know history and be able to use it. Only then will the development of surgery lead to the preservation of the quality of life of patients. In the history of surgery for acoustic neuromas, the stages of its development are clearly visible from the description of the clinical picture through the study of the anatomy of the cerebellopontine angle to modern microsurgical removal.

Arachnoid Cyst of the Cerebellopontine Angle: A Systematic Literature Review.

OBJECTIVE: The role of surgical management of arachnoid cyst (AC) of the cerebellopontine angle (CPA) is uncertain. This topic has remained controversial with varying contradictory recommendations in the literature, which is limited to mostly case reports. We aimed to provide a comprehensive summary and analysis of symptoms, operative techniques, outcomes, and recurrence of all available surgical cases of AC of the CPA to date. METHODS: A systematic literature search was performed in May 2022 querying several scientific databases. Inclusion criteria specified all studies and case reports of patients with AC located at the CPA for which any relevant surgical procedures were performed. RESULTS: A total of 55 patients from the literature and 5 treated at our institution were included. Mean patient age was 29 years (range, 0.08-79 years), with nearly twice (1.7×) as many female as male patients (37 female, 22 male). Headaches (35%), hearing loss (30%), vertigo (22%), and ataxia (22%) were the most common presentations. Following surgery, 95% experienced symptom improvement, with complete resolution in 64%. Of patients with hearing loss, 44% reported a return to normal. The rate of mortality was 1.69%, and 10% of tumors recurred (mean follow-up 2.3 years [range, 0-15 years]. CONCLUSIONS: Symptomatic AC of the CPA is rare. It exhibits a proclivity for females and commonly manifests with headache, hearing loss, vertigo, and ataxia. While careful selection for surgical candidacy is needed and intervention should be reserved for patients with severe symptoms, surgical decompression is an effective tool for symptom alleviation and recovery.

Fully neuroendoscopic resection of cerebellopontine angle tumors through a retrosigmoid approach: a retrospective single-center study.

The objective of this study is to preliminarily investigate the surgical safety, efficacy, techniques, and clinical value of fully neuroendoscopic surgery for the resection of cerebellopontine angle (CPA) tumors via a retrosigmoid approach. The clinical data of 47 cerebellopontine angle area (CPA) tumors that were treated by full neuroendoscopic surgery from June 2014 to June 2023 were retrospectively analyzed. The efficacy and advantages of the surgical techniques were evaluated based on indicators such as duration of the surgery, neuroendoscopic techniques, intraoperative integrity of nerves and blood vessels, extent of tumor resection, outcomes or postoperative symptoms, and incidence of complications. The 47 cases of cerebellopontine angle tumors include 34 cases of epidermoid cysts, 7 cases of vestibular schwannomas, and 6 cases of meningiomas. All patients underwent fully neuroendoscopic surgery. Twenty tumors were removed using the one-surgeon two-hands technique, and 27 tumors were removed using the two-surgeons four-hands technique. The anatomical integrity of the affected cranial nerves was preserved in all 47 cases. None of the patients suffered a postoperative hemorrhage, cerebrospinal fluid leak, and aseptic or septic meningitis, or died. The rate of total tumor resection was 72.3% (34/47), and the symptom improvement rate was 89.4% (42/47). All patients were followed up for 2 to 12 months, and none died nor showed any signs of tumor recurrence. By analyzing 47 fully neuroendoscopic resections of CPA tumors using the posterior sigmoid sinus approach in our center, we believe that such method allows complete, safe, and effective resection of CPA tumors and is thereby worthy of clinical promotion.

Cerebellopontine angle tumor presenting as acute audiovestibular syndrome.

BACKGROUND: Acute audiovestibular deficits may be a harbinger of vestibular schwannoma (VS). OBJECTIVE: To investigate clinical and laboratory features of 25 consecutive patients with VS presenting with acute audiovestibular deficits. METHODS: A symptomatic combination of acute audiovestibular deficits was investigated. Audiometric and vestibular function tests, and internal auditory canal magnetic resonance imaging (IAC MRI) results were evaluated. RESULTS: Varying combinations of symptoms may develop in VS patients with acute audiovestibular deficits, of whom sudden hearing loss (HL) without acute vertigo or acute facial nerve palsy (FNP) was most common. The most common audiometric configuration was high-tone hearing loss, and no patient showed low-tone hearing loss. IAC MRI demonstrated that the tumor had an intracanalicular portion and attachment to the bony IAC wall in all patients and widened the IAC wall in some patients. CONCLUSION: Different symptomatic combinations of acute audiovestibular deficits may develop in patients with VS. Awareness about the possibility of VS as a cause of sudden HL, acute vertigo, and acute FNP, as well as subsequent IAC MRI scanning is vital to earlier diagnosis of VS in these patients.

Simultaneous cochlear implantation during resection of a cerebellopontine angle meningioma: case report.

Cerebellopontine angle (CPA) meningiomas commonly involve the internal auditory canal (IAC). We report a case of a 68-year-old lady with idiopathic profound bilateral deafness with a meningioma which was discovered on workup for cochlear implantation. We performed simultaneous excision of her CPA and IAC meningioma with insertion of a cochlear implant (CI). She regained functional hearing with marked improvement in quality of life. Intraoperative electrophysiological testing can be used to confirm preservation of the cochlear nerve enabling simultaneous implantation which is preferable for clinical and logistical reasons. This creates an option for hearing rehabilitation at the time of IAC/CPA tumour surgery in appropriate patients.

Upfront Radiosurgery vs a Wait-and-Scan Approach for Small- or Medium-Sized Vestibular Schwannoma: The V-REX Randomized Clinical Trial.

Importance: Current guidelines for treating small- to medium-sized vestibular schwannoma recommend either upfront radiosurgery or waiting to treat until tumor growth has been detected radiographically. Objective: To determine whether upfront radiosurgery provides superior tumor volume reduction to a wait-and-scan approach for small- to medium-sized vestibular schwannoma. Design, Setting, and Participants: Randomized clinical trial of 100 patients with a newly diagnosed (<6 months) unilateral vestibular schwannoma and a maximal tumor diameter of less than 2 cm in the cerebellopontine angle as measured on magnetic resonance imaging. Participants were enrolled at the Norwegian National Unit for Vestibular Schwannoma from October 28, 2014, through October 3, 2017; 4-year follow-up ended on October 20, 2021. Interventions: Participants were randomized to receive either upfront radiosurgery (n = 50) or to undergo a wait-and-scan protocol, for which treatment was given only upon radiographically documented tumor growth (n = 50). Participants underwent 5 annual study visits consisting of clinical assessment, radiological examination, audiovestibular tests, and questionnaires. Main Outcomes and Measures: The primary outcome was the ratio between tumor volume at the trial end at 4 years and baseline (V4:V0). There were 26 prespecified secondary outcomes, including patient-reported symptoms, clinical examinations, audiovestibular tests, and quality-of-life outcomes. Safety outcomes were the risk of salvage microsurgery and radiation-associated complications. Results: Of the 100 randomized patients, 98 completed the trial and were included in the primary analysis (mean age, 54 years; 42% female). In the upfront radiosurgery group, 1 participant (2%) received repeated radiosurgery upon tumor growth, 2 (4%) needed salvage microsurgery, and 45 (94%) had no additional treatment. In the wait-and-scan group, 21 patients (42%) received radiosurgery upon tumor growth, 1 (2%) underwent salvage microsurgery, and 28 (56%) remained untreated. For the primary outcome of the ratio of tumor volume at the trial end to baseline, the geometric mean V4:V0 was 0.87 (95% CI, 0.66-1.15) in the upfront radiosurgery group and 1.51 (95% CI, 1.23-1.84) in the wait-and-scan group, showing a significantly greater tumor volume reduction in patients treated with upfront radiosurgery (wait-and-scan to upfront radiosurgery ratio, 1.73; 95% CI, 1.23-2.44; P = .002). Of 26 secondary outcomes, 25 showed no significant difference. No radiation-associated complications were observed. Conclusion and relevance: Among patients with newly diagnosed small- and medium-sized vestibular schwannoma, upfront radiosurgery demonstrated a significantly greater tumor volume reduction at 4 years than a wait-and-scan approach with treatment upon tumor growth. These findings may help inform treatment decisions for patients with vestibular schwannoma, and further investigation of long-term clinical outcomes is needed. Trial Registration: ClinicalTrials.gov Identifier: NCT02249572.

Application of Neuronavigation in Microvascular Decompression: Optimizing Craniotomy and 3D Reconstruction of Neurovascular Compression.

OBJECT: Microvascular decompression (MVD) is the best curative treatment for trigeminal neuralgia and hemifacial spasm. We used the neuronavigation to reconstruct the 3D image of cranial nerve and blood vessel to identify the neurovascular compression, and to reconstruct the venous sinus and skull to optimize craniotomy. PATIENTS AND METHODS: A total of 11 trigeminal neuralgia and 12 hemifacial spasm cases were selected. All patients had preoperative MRI which included 3D Time of Flight (3D-TOF), Magnetic Resonance Venography (MRV) and computer tomography (CT) for navigation. Imaging sequences were fused and reconstructed by navigation system before operation. The 3D-TOF images were used to delineate cranial nerve and vessel. The CT and MRV images were used to mark transverse sinus and the sigmoid sinus for craniotomy. All patients underwent MVD and have the preoperative view compared with intraoperative findings. RESULTS: Approaching to the cerebellopontine angle right after opening the dura and got no cerebellar retracion or petrosal vein rupture during craniotomy. Ten of 11 trigeminal neuralgia and all 12 hemifacial spasm patients got excellent preoperative 3D reconstruction fusion images, which were also confirmed by intraoperative findings. All 11 trigeminal neuralgia patients and 10 of 12 hemifacial spasm patients were symptom free without any neurological complications just after the surgery. Other 2 hemifacial spasm patients got delayed resolution in 2 months after surgery. CONCLUSIONS: Through the neuronavigation guided craniotomy and the 3D neurovascular reconstruction, surgeons can better identify the compression of nerve and blood vessel, and reduce complications.

Neuroanaesthetic challenges in a pregnant patient with a huge cerebellopontine angle meningioma.

Intracranial malignancy among pregnant women is extremely rare. Neuroanaesthesia for such high-risk patients demands extreme precautions. Our patient presented with a huge right cerebellopontine angle meningioma during the first trimester of her pregnancy. We share our valuable perianaesthetic challenges in managing her tumour-debulking surgery and a brief review of intracranial neoplasm during pregnancy.

Bruns Nystagmus in Cerebellopontine Angle Hemangioblastoma.

Bruns nystagmus is a form of jerk nystagmus that has a localizing value in cerebellopontine angle (CPA) tumors. Hemangioblastomas involving the CPA is rare. A case of a 57-year-old male presented with Bruns nystagmus which led to the discovery of a large CPA hemangioblastoma is described. The nystagmus was compatible with the laterality of the tumor. High quality video of Bruns nystagmus was recorded.

Microsurgical anatomy and pathoanatomy of the outer arachnoid membranes in the cerebellopontine angle: cadaveric and intraoperative observations.

PURPOSE: The cerebellopontine angle (CPA) is a frequent region of skull base pathologies and therefore a target for neurosurgical operations. The outer arachnoid is the key structure to approach the here located lesions. The goal of our study was to describe the microsurgical anatomy of the outer arachnoid of the CPA and its pathoanatomy in case of space-occupying lesions. METHODS: Our examinations were performed on 35 fresh human cadaveric specimens. Macroscopic dissections and microsurgical and endoscopic examinations were performed. Retrospective analysis of the video documentations of 35 CPA operations was performed to describe the pathoanatomical behavior of the outer arachnoid. RESULTS: The outer arachnoid cover is loosely attached to the inner surface of the dura of the CPA. At the petrosal surface of the cerebellum the pia mater is strongly adhered to the outer arachnoid. At the level of the dural penetration of the cranial nerves, the outer arachnoid forms sheath-like structures around the nerves. In the midline, the outer arachnoid became detached from the pial surface and forms the base of the posterior fossa cisterns. In pathological cases, the outer arachnoid became displaced. The way of displacement depends on the origin of the lesion. The most characteristic patterns of changes of the outer arachnoid were described in case of meningiomas, vestibular schwannomas, and epidermoid cysts of the CPA. CONCLUSION: The knowledge of the anatomy of the outer arachnoid of the cerebellopontine region is essential to safely perform microsurgical approaches as well as of dissections during resection of pathological lesions.

Combined telovelar posterolateral (far lateral) approach for the resection of a large posterior fossa ependymoma: how I do it.

BACKGROUND: Ependymomas are glial cell tumors whose recommended treatment, according to the recent European guidelines, is surgical. Patient outcomes, in terms of progression-free survival and overall survival, are strongly related to the extent of resection. However, in some cases, critical locations and/or large dimensions could make a gross total resection challenging. In this article, we describe the surgical anatomy and technique of a combined telovelar-posterolateral approach for the resection of a giant posterior fossa ependymoma. METHODS: A 24-year-old patient who presented to our institution complaining of a 3-month history of headache, vertigo, and imbalance. Preoperative MRI scans showed a large mass within the fourth ventricle, extending towards the left cerebellopontine angle and perimedullary space through the homolateral Luschka foramen. Surgical treatment was proposed with the aims of releasing the preoperative symptoms, obtaining the tumor's histopathological and molecular definition, and preventing any future neurological deterioration. The patient gave his written consent for surgery and consented to the publication of his images. A combined telovelar-posterolateral approach was then performed to maximize the tumor's exposure and resection. Surgical technique and anatomical exposure have been extensively described, and a 2-dimensional operative video has been included. RESULTS: The postoperative MRI scan demonstrated an almost complete resection of the lesion, with only a millimetric tumor remnant infiltrating the uppermost portion of the inferior medullary velum. Histo-molecular analysis revealed a grade 2 ependymoma. The patient was discharged home neurologically intact. CONCLUSIONS: The combined telovelar-posterolateral approach allowed to achieve a near total resection of a giant multicompartimental mass within the posterior fossa in a single surgical stage.

Diluted intracisternal papaverine for microvascular protection of cranial nerves during vestibular schwannoma and cerebello-pontine angle surgery. Commentary and review of the literature.

Vasospasm after resection of skull base tumors is a rare complication that often produces relevant ischemic sequelae. This review of the literature reports a number of published experiences that can help determine the potential causes of vasospasm after cerebello-pontine angle (CPA) tumor and -in particular-vestibular schwannoma (VS) resection, the ways to prevent it, and the methods to obtain the correct diagnosis. The cause appears to be multifactorial and the surgical approach may contribute to the pathogenesis of vasospasm. Neurosurgeons must pay attention to detect possible vasospasm at an early stage of cerebello-pontine. Cerebral blood flow measurement and transcranial Doppler are useful monitoring tools. Intra-operative prevention of vasospasm during CPA tumor resection with papaverine hydrochloride (PPV) seems to play a relevant role. In particular, PPV is a direct-acting vasodilator used to manage vasospasm during various neurosurgical operations. There is large uncertainty about intracisternal PPV dose-related efficacy and side effects. Dilution of PPV in saline prior to application is recommended to avoid complications. In our experience, in line with the literature, we use a pure PPV without excipients 60 mg/2 ml diluted in 20 cc of 0,9% saline solution (0,3%) to prevent Hearing Loss during Posterior Fossa Microvascular Decompression for Typical Trigeminal Neuralgia and other cranial nerves potentially involved during VS and other CPA tumor resection. The aim of this commentary is to analyze and discuss the role of diluted intracisternal PPV for microvascular protection of cranial nerves during CPA tumor surgery.

Radical resection of trigeminal schwannoma at the cerebellopontine angle with support of the digital robotic exoscope Synaptive Modus V system: A case report and literature review.

RATIONALE AND PATIENT CONCERNS: We report on a 67-year-old woman who experienced drowsy mental status, facial numbness, and hearing loss on the right side; the symptom gradually worsened over the last 4 years. Brain magnetic resonance imaging revealed a 4.8 × 1.8 × 2.6 cm lesion located in the right cerebellopontine angle. INTERVENTIONS: She underwent surgery with the retrosigmoid suboccipital approach and support from the digital robotic exoscope Synaptive Modus V system. To the best of our knowledge, this is the first reported case that used the robotic exoscope system in Vietnam, and also in Asia. DIAGNOSIS: We performed radical resection of the tumor, the surgery position and the pathology result concluded the diagnosis was trigeminal schwannoma. OUTCOMES: After 30 months of follow-up, she fully recovered and the magnetic resonance imaging showed radical resection of the tumor. LESSONS: The aim of this study is to share our experience with the robotic exoscope system, which can improve optical field and image resolution, hence creating an opportunity for surgery that otherwise is impossible. The application of this robotic exoscope system is a breakthrough in neurosurgery in developing countries, such as Vietnam.

Malignant Cerebellopontine Angle Peripheral Nerve Sheath Tumor with Divergent Mesenchymal (Cartilaginous) Differentiation Presenting with Catastrophic Hemorrhage: Case Report and Review.

Malignant peripheral nerve sheath tumors of the cerebellopontine angle are rare, especially even outside of the context of neurofibromatosis or malignant transformation of previously radiated vestibular schwannomas. This case report describes a case of a presumed vestibular schwannoma without previous radiation or history of neurofibromatosis presenting with progressive hearing loss, facial weakness, growth, and ultimately catastrophic hemorrhage requiring urgent surgery. Histopathology revealed an exceptionally rare malignant peripheral nerve sheath tumor with divergent mesenchymal (chondrosarcomatous) differentiation with few rigorously interrogated cases in the literature. In retrospect, facial weakness, growth, and early intratumoral hemorrhage were harbingers of atypical malignant pathology. We advocate for a heightened index of suspicion, shorter interval follow-up, and consideration of early surgery in such cases in hopes of preventing potentially catastrophic outcomes.

Solitary Sclerotic Fibroma of Right Cerebellopontine Angle.

Sclerotic fibroma (storiform collagenoma) is a fibrotic tumor that occurs mainly in patients with Cowden syndrome, but it can also occur in isolation, as detailed in previous reports. Here we present a case of a solitary sclerotic fibroma in cerebellopontine angle. Brain magnetic resonance imaging revealed a lesion showing hypointense signal on both T1 and T2. The lesion was not enhanced after administering gadolinium. The tumor was removed integrally by surgery.

Meningiomas of the Cerebellopontine Angle: Tips and Pearls for Safe Surgical Resection.

AIM: To present our series of cerebellopontine angle (CPA) meningiomas, and to provide some innovative surgical steps for safe removal of these tumors. MATERIAL AND METHODS: The clinical, radiological, and surgical characteristics of 32 patients with meningioma in the CPA were retrospectively analyzed. A statistical analysis was performed to determine the factors that affect the incidence of complication. RESULTS: The mean age was 49.5 yr, and 87.5% of patients were men had World Health Organization (WHO) grade I meningioma, while the remaining patients had WHO grade II tumors. The mean tumor volume was 33.98 mL, and gross total resection was performed on 65.6% of the patients. Preoperative tumor size/extension and extent of resection were related with the development of complications. CONCLUSION: CPA meningiomas are challenging tumors to remove safely. Important risk factors for the development of postoperative complications include tumor size and extent of resection.

Utility of dynamic susceptibility contrast MRI for differentiation between paragangliomas and meningiomas in the cerebellopontine angle and jugular foramen region.

PURPOSE: Differentiation of paragangliomas and meningiomas can be a challenge. This study aimed to assess the utility of dynamic susceptibility contrast perfusion MRI (DSC-MRI) to distinguish paragangliomas from meningiomas. METHODS: This retrospective study included 40 patients with paragangliomas and meningiomas in the cerebellopontine angle and jugular foramen region between March 2015 and February 2022 in a single institution. Pretreatment DSC-MRI and conventional MRI were performed in all cases. Normalized relative cerebral blood volume (nrCBV), relative cerebral blood flow (nrCBF), relative mean transit time (nrMTT), and time to peak (nTTP) as well as conventional MRI features were compared between the 2 tumor types and between meningioma subtypes as appropriate. Receiver operating characteristic curve and multivariate logistic regression analysis were performed. RESULTS: Twenty-eight meningiomas including 8 WHO grade II meningiomas (12 males, 16 females; median age 55 years) and 12 paragangliomas (5 males, 7 females; median age 35 years) were included in this study. Paragangliomas had a higher rate of cystic/necrotic changes (10/12 vs 10/28; P = 0.014), a higher rate of internal flow voids (9/12 vs 8/28; P = 0.013), higher nrCBV (median 9.78 vs 6.64; P = 0.04), and shorter nTTP (median 0.78 vs 1.06; P < 0.001) than meningiomas. There was no difference in conventional imaging features and DSC-MRI parameters between meningioma subtypes. nTTP was identified as the most significant parameter for the 2 tumor types in the multivariate logistic regression analysis (P = 0.009). CONCLUSIONS: In this small retrospective study, DSC-MRI perfusion differences were observed between paragangliomas and meningiomas, but not between grade I and II meningiomas.

Fascicular-Sparing Technique for Resection of Cerebellopontine Angle Facial Nerve Schwannoma.

Surgery of cerebellopontine angle (CPA) facial nerve schwannoma (FNS) in patients with good facial nerve function is a challenge.1-10Video 1 highlights the fascicular-sparing technique for resection of a CPA FNS. A 41-year-old male patient symptomatic with persistent headaches and tinnitus underwent a retrosigmoid approach for a right cystic CPA tumor, presumed vestibular schwannoma. Intraoperatively, the facial nerve was identified as fine multiple strands splayed around the perimetry of the tumor, which elicited a motor response at a low threshold stimulation. This finding led to the intraoperative diagnosis of FNS according to the reported criteria.5 Neuromonitoring-assisted fascicular-sparing resection technique was performed. It involved the gradual separation of the uninvolved nerve fibers using a fine-stimulating dissector at a threshold of 0.2 mA. Entry into the tumor was at a stimulation silent cyst. The tumor was debulked with preservation of the endoneurium and pulse irrigation hemostasis. A near-total resection was performed. The patient was discharged on the second postoperative day with a House-Brackman III facial nerve deficit. The deficit remained stable during the following annual follow-up visits. Resection of CPA FNS is indicated at the earliest sign of deficit. However, it might be encountered as masquerading at the surgery of an acoustic tumor. The fascicular-sparing technique is critical in avoiding injuries to the endoneurium during the resection and with the ability to preserve function. The sparing of endoneurium avoids collagenization, fibrosis, and ischemia of the nerve, which are known to be the pathologic substrate of worse functional outcomes.

Cerebellopontine angle meningiomas: LINAC stereotactic radiosurgery treatment.

OBJECTIVES: To evaluate the efficacy of treatment with linear accelerator-based stereotactic radiosurgery (LINAC) in cerebellopontine angle meningiomas. METHODS: We analyzed 80 patients diagnosed with cerebellopontine angle meningiomas between 2001 and 2014, treated with stereotactic radiosurgery (SRS), of whom 81.9% (n=68) were women, with an average age of 59.1 years (32-79). SRS was applied as primary treatment in 83.7% (n=67) and in 16.3% (n=13) as an adjuvant treatment to surgery. SRS treatment was provided using LINAC (Varian 600, 6MeV) with M3 micromultilamines (brainLab) and stereotactic frame. The average tumor volume was 3.12cm3 (0.34-10.36cm3) and the coverage dose was 14Gy (12-16Gy). We performed a retrospective descriptive analysis and survival analysis was performed with the Kaplan-Meier method and multivariate analysis to determine those factors predictive of tumor progression or clinical improvement. RESULTS: After an average follow-up period of 86.9 months (12-184), the tumor control rate was 92.8% (n=77). At the end of the study, there was an overall reduction in tumor volume of 32.8%, with an average final volume of 2.11cm3 (0-10.35cm3). The progression-free survival rate at 5, 10 and 12 years was 98%, 95% and 83.3% respectively. The higher tumor volume (p=0.047) was associated with progression. There was clinical improvement in 26.5% (n=21) of cases and clinical worsening in 16.2% (n=13). Worsening is related to the radiation dose received by the brainstem (p=0.02). Complications were 8.7% (7 cases) of hearing loss, 5% (4 cases) of brain radionecrosis, and 3.7% (3 cases) of cranial nerve V neuropathy. Hearing loss was related to initial tumor size (p=0.033) and maximum dose (p=0.037). The occurrence of radionecrosis with the maximum dose (p=0.037). CONCLUSIONS: Treatment of cerebellopontine angle meningiomas with single-dose SRS using LINAC is effective in the long term. Better tumor control rates were obtained in patients with small lesions.