INTRODUCTION:Brain metastases occur in approximately 20% to 40% of individuals annually diagnosed with cancer. This poor prognostic feature can severely reduce life expectancy and quality of life. Stereotactic radiosurgery (SRS) has been shown to provide excellent tumor control and clinical outcomes. ZAP-X (Zap Surgical Systems Inc., San Carlos, CA, USA) is an innovative self-shielded gyroscopic stereotactic radiosurgery (GRS) system to help further address these needs. In this study, we evaluate the clinical outcomes of patients with brain metastases who have undergone treatment with ZAP-X in a single institution. METHODS:Medical records of all patients with brain metastases treated with GRS between May 2021 and May 2023 were reviewed as a retrospective case series. Demographics, clinical symptoms, treatment trajectory, and follow-up data were collected and analyzed. RESULTS:A total of 46 patients with 140 combined brain metastases were included in this cohort. Of them, 58.7% (N=27) were female patients, and the mean age was 63 years (range 36-82). The primary pathologies were non-small cell lung cancer (NSCLC; N22, 47.8%), breast cancer (N11, 23.9%), melanoma (N5, 10.9%), and others (N8, 17.4%). The prescription dose was 18 Gy if the patient previously received whole-brain radiotherapy (WBRT); otherwise, 20 Gy. All patients received dexamethasone (3x4 mg PO). The most common symptoms included headache (45.7%), motor disturbances (30.4%), and seizures (21.7%). Mean follow-up time was 8.5 months (range 0-19). Systemic response using Response Evaluation Criteria in Solid Tumors (RECIST) criteria was 17.3% complete response, 10.9% partial response, 45.7% stable disease, and 26.1% progression of disease. Tumor control was 73.9% according to the Response Assessment in Neuro-Oncology (RANO) criteria for brain metastases. CONCLUSIONS:GRS is a novel image-guided linear accelerator-based, self-shielding gyroscopic radiosurgery platform that does not require a vault. This study shows that GRS achieves comparable results to traditional SRS platforms in the treatment of brain metastases.

Background/Objectives: Anterior cervical meningocele (ACM) is a rare congenital condition characterized by the herniation of the meninges through a defect in the anterior vertebral column. ACM clinical management is not standardized because this condition is rare, and guidelines are missing. Hereby, a systematic literature review is performed to determine management options and outcomes. Methods: The case of a 62-year-old patient with incidental diagnosis of C3-C5 ACM is presented. A systematic review was conducted using standard PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for all cases of anterior cervical meningocele from 1837 to 2025. Results: The review provided nine clinical cases and our illustrative case. The median age was 47 years, with a predominance of female patients (70%). The most common presenting symptom was neck pain (60%), followed by paresthesia and hypoesthesia in the upper limbs. Four patients underwent conservative management with clinical and radiological follow-up, while four patients underwent neurosurgical intervention. Surgical treatment was complicated by cerebrospinal fluid (CSF) leak in two patients, and one of them developed meningitis. Conclusions: ACM is typically associated with mesodermal dysplasia and dural ectasia. ACM usually has a benign clinical course, requiring neurological follow-up and conservative management alone. However, a surgical approach should be considered in cases of vertebral instability or symptoms related to upper airway compression or upper gastrointestinal tract compression despite the high risk of CSF leak when surgical repair is attempted.

Background/Objectives: The 2021 WHO Classification of Central Nervous System (CNS) tumors emphasizes the integration of molecular data with histopathological features. Lower-grade gliomas (LGGs) represent a heterogeneous group of neoplasms with variable clinical behavior. This study aimed to explore the molecular landscape of a single-institution series of LGGs using targeted next-generation sequencing (NGS). Methods: Eleven adult patients diagnosed with LGG between 2015 and 2024 at Cattinara University Hospital (Trieste, Italy) were retrospectively analyzed. DNA and RNA were extracted from formalin-fixed, paraffin-embedded (FFPE) tissue and analyzed using the TruSight Oncology 500 panel (Illumina). Mutational, amplification, and transcriptomic profiles were evaluated. Results: IDH1 mutations were the most frequent alteration (75%), commonly co-occurring with TP53 and ATRX mutations, consistent with the canonical IDH-mutant astrocytoma profile. CDK4 amplification was found in four cases, while MYCN amplification and MET amplification were each identified in isolated cases. Two diffuse IDH-wild-type gliomas displayed aggressive clinical courses and shorter survival, and one was reclassified as glioblastoma (grade 4) based on EGFR amplification. The transcriptome analysis revealed heterogeneous expression signatures and distinct clustering of IDH1/ATRX-mutant tumors. Conclusions: Targeted NGS confirmed the key molecular features of diffuse gliomas and enabled precise WHO 2021 classification even in archival FFPE samples. Despite the exploratory nature of the analysis on a small population, the study underscores the biological and transcriptional heterogeneity of LGGs and highlights the limitations of tumor-only sequencing approaches. Broader genomic profiling and matched normal controls are warranted to refine the interpretation of rare or non-canonical variants.

OBJECTIVE Leiomyosarcoma (LMS) is a rare, aggressive soft -tissue sarcoma that seldom spreads to the bone. The spine can be either the site of LMS osseous metastases or the primary tumor site. The optimal treatment option for spinal LMS is still unclear. The authors present a cohort of patients with spinal LMS treated with either upfront surgery or upfront CyberKnife stereotactic radiosurgery (SRS). METHODS The authors retrospectively studied the clinical and radiological outcomes of 17 patients with spinal LMS treated at their institution between 2004 and 2020. Either surgery or SRS was used as the upfront treatment. The clinical and radiological outcomes were assessed. A systematic review of the literature was also conducted. RESULTS Of the 17 patients (20 spinal lesions), 12 (70.6%) were female. The median patient age was 61 years (range 41-80 years). Ten patients had upfront surgery for their spinal lesions, and 7 had upfront CyberKnife radiosurgery. The median follow-up was 11 months (range 0.3-130 months). The median overall survival (OS) for the entire cohort was 13 months (range 0.3-97 months). In subgroup analysis, the median OS was lower for the surgical group (13 months, range 0.3-50 months), while the median OS for the SRS group was 15 months (range 5-97 months) (p = 0.5). Forty percent (n = 4) of those treated with surgery presented with local recurrence at a median of 6.7 months (range 0.3-36 months), while only 14% (n = 1) of those treated with CyberKnife radiosurgery had local recurrence after 5 months. Local tumor control (LTC) rates at the 6-, 12-, and 18 -month follow-ups were 72%, 58%, and 43%, respectively, for the SRS group and 40%, 30%, and 20%, respectively, for the surgery group (p < 0.05). The literature review included 35 papers with 70 patients harboring spinal LMS; only 2 patients were treated with SRS. The literature review confirms the clinical and radiological outcomes of the surgical group, while data on SRS are anecdotal. CONCLUSIONS The authors present the largest series in the literature of spinal LMS and the first on SRS for spinal LMS. This study shows that LTC is statistically significantly better in patients receiving upfront SRS instead of surgery. The OS does not appear different between the two groups.

BACKGROUND AND OBJECTIVES:Ependymoma is commonly classified as World Health Organization grade 2 with the anaplastic variant categorized as grade 3. Incomplete resection or anaplastic features can result in unfavorable outcomes. Stereotactic radiosurgery (SRS) provides a minimally invasive approach for recurrent ependymomas. Our study investigates the efficacy and safety of SRS for grade 2 and 3 ependymomas in pediatric and adult populations. METHODS:We conducted a retrospective analysis on 34 patients with 75 ependymomas after CyberKnife SRS between 1998 and 2023. Fourteen were pediatric (3-18 years), and 20 were adult (19-75 years) patients. The median age was 21 years, and the median tumor volume was 0.64 cc. The median single-fraction equivalent dose was 16.6 Gy, with SRS administered at 77% of the median isodose line. RESULTS:After a median follow-up of 42.7 months (range: 3.8-438.3), 22.7% of ependymomas progressed. The 5-year local tumor control rate was 78.1%, varying between 59.6% and 90.2% for children and adults, with grade 2 at 85.9% compared with 58.5% for grade 3 tumors. The 5-year overall survival rate was 73.6%, notably higher in adults (94.7%) than in children (41%), and 100% for grade 2 but decreased to 35.9% for grade 3 patients. The 5-year progression-free survival rate was 68.5%, with 78.3% and 49.2% for adults and children, respectively, and a favorable 88.8% for grade 2, contrasting with 32.6% for grade 3 patients. Symptom improvement was observed in 85.3% of patients. Adverse radiation effects occurred in 21.4% of pediatric patients. CONCLUSION:Our study supports SRS as a viable modality for pediatric and adult patients with grade 2 and 3 ependymomas. Despite lower local tumor control in pediatric and grade 3 cases, integrating SRS holds promise for improved outcomes. Emphasizing careful patient selection, personalized treatment planning, and long-term follow-up is crucial for optimal neurosurgical outcomes.

Purpose Accurate and automated early survival prediction is critical for patients with glioblastoma (GBM) as their poor prognosis requires timely treatment decision-making. To address this need, we developed a deep learning (DL)-based end-to-end workflow for GBM overall survival (OS) prediction using pre-resection basic structural multiparametric magnetic resonance images (Bas-mpMRI) with a multi-institutional public dataset and evaluated it with an independent dataset of patients on a prospective institutional clinical trial. Materials and methods The proposed end-to-end workflow includes a skull-stripping model, a GBM sub-region segmentation model and an ensemble learning-based OS prediction model. The segmentation model utilizes skull-stripped Bas-mpMRIs to segment three GBM sub-regions. The segmented GBM is fed into the contrastive learning-based OS prediction model to classify the patients into different survival groups. Our datasets include both a multi-institutional public dataset from Medical Image Computing and Computer Assisted Intervention (MICCAI) Brain Tumor Segmentation (BraTS) challenge 2020 with 235 patients, and an institutional dataset from a 5-fraction SRS clinical trial with 19 GBM patients. Each data entry consists of pre-operative Bas-mpMRIs, survival days and patient ages. Basic clinical characteristics are also available for SRS clinical trial data. The multi-institutional public dataset was used for workflow establishing (90% of data) and initial validation (10% of data). The validated workflow was then evaluated on the institutional clinical trial data. Results Our proposed OS prediction workflow achieved an area under the curve (AUC) of 0.86 on the public dataset and 0.72 on the institutional clinical trial dataset to classify patients into 2 OS classes as long-survivors (>12 months) and short-survivors (<12 months), despite the large variation in Bas-mpMRI protocols. In addition, as part of the intermediate results, the proposed workflow can also provide detailed GBM sub-regions auto-segmentation with a whole tumor Dice score of 0.91. Conclusion Our study demonstrates the feasibility of employing this DL-based end-to-end workflow to predict the OS of patients with GBM using only the pre-resection Bas-mpMRIs. This DL-based workflow can be potentially applied to assist timely clinical decision-making.

Abstract Cranial nerve metastases (CNM) can be primary via leptomeningeal metastasis or secondary by spread due to head and neck cancers or due to distant tumor metastasis to the skull base. In addition, they may cause cranial nerve-related symptoms that can impact patient quality of life. We performed a single-center retrospective cohort study of all patients with CNM treated with SRS at our institution between April 2003 and February 2021. Demographic and clinical information were retrieved from the electronic medical record. Median follow-up was 12.9 months. Our study cohort consisted of 9 patients with primary CNM and 8 with secondary CNM – for a total of 17 patients, with a total of 33 lesions (23 primary, 10 secondary). Eleven patients (64.7%) had symptoms caused by cranial nerve metastases. Symptoms were resolved in 5 of 11 patients (45.5%) after SRS. Patients with secondary CNM were more likely to have cranial nerve symptoms and more likely to have resolution of symptoms following SRS. The median time between SRS and symptom improvement was 3 months. Local tumor control was achieved in 30 of 33 lesions (90.9%). Local tumor control at 6 months and at 1 year were 100%. Our study suggests that SRS may be a safe and effective treatment for cranial nerve metastasis providing 90.9% local tumor control at final follow-up, and symptomatic stability or improvement in 90.9% of symptomatic cases. Patients with secondary CNM may stand to benefit more from a symptom management standpoint.

Background/Objectives: Medulloblastoma is the most common malignant brain tumor in children. In recent decades, the therapeutic landscape has undergone significant changes, with stereotactic radiosurgery (SRS) emerging as a promising treatment for recurrent cases. Our study provides a comprehensive analysis of the long-term efficacy and safety of SRS in recurrent medulloblastomas across both pediatric and adult patients at a single institution. Methods: We retrospectively reviewed the clinical and radiological records of patients who underwent CyberKnife SRS for recurrent cranial medulloblastomas at our institution between 1998 and 2023. Follow-up data were available for 15 medulloblastomas in 10 patients. The cohort comprised eight pediatric patients (ages 3–18) and two adult patients (ages 19–75). The median age at the time of SRS was 13 years, the median tumor volume accounted for 1.9 cc, the median biologically equivalent dose (BED) was 126 Gy, and the single-fraction equivalent dose (SFED) was 18 Gy. The SRS was administered at 75% of the median isodose line. Results: Following a median follow-up of 39 months (range: 6–78), 53.3% of the medulloblastomas progressed, 13.3% regressed, and 33.3% remained stable. The 3-year local tumor control (LTC) rate for all medulloblastomas was 65%, with lower rates observed in the adult cohort (50%) and higher rates in pediatric patients (67%). The 3-year overall survival (OS) rate was 70%, with significantly higher rates in pediatric patients (75%) compared to adult patients (50%). The 3-year progression-free survival (PFS) rate was 58.3%, with higher rates in pediatric patients (60%) compared to adult patients (50%). Two pediatric patients developed radiation-induced edema, while two adult patients experienced radiation necrosis at the latest follow-up, with both adult patients passing away. Conclusions: Our study provides a complex perspective on the efficacy and safety of CyberKnife SRS in treating recurrent cranial medulloblastomas across pediatric and adult populations. The rarity of adverse radiation events (AREs) underscores the safety profile of SRS, reinforcing its role in enhancing treatment outcomes. The intricacies of symptomatic outcomes, intertwined with factors such as age, tumor location, and prior surgeries, emphasize the need for personalized treatment approaches. Our findings underscore the imperative for ongoing research and the development of more refined treatment strategies for recurrent medulloblastomas. Given the observed disparities in treatment outcomes, a more meticulous tailoring of treatment approaches becomes crucial.

Abstract BACKGROUND Ependymoma is typically classified as WHO grade 2 and its anaplastic variant as grade 3. Despite standard treatment approaches, incomplete resection or anaplastic features can lead to poor prognosis. Stereotactic radiosurgery (SRS) is a promising minimally invasive option for recurrent ependymomas after surgery and radiation therapy. This study aims to evaluate the efficacy and safety of CyberKnife radiosurgery in treatment of WHO grade II versus III ependymomas in both pediatric and adult populations. MATERIAL AND METHODS In our study, we evaluated the clinical and radiological records of patients who underwent CyberKnife SRS for ependymoma at our institution between 1998 and 2023. The follow-up data were available for a total of 75 ependymomas in 34 patients. The study population consisted of 14 pediatric patients (ages 3-18) and 20 adult patients (ages 19-75). The median age was 21 years and the median tumor volume accounted for 0.64 cc. The median biologically equivalent dose (BED) and single-fraction equivalent dose (SFED) were 108 Gy and 16.6 Gy, respectively. The SRS was administered at the 77% of the median isodose line. RESULTS At a median follow-up of 42.7 months (range: 3.8-438.3) after treatment, our analysis revealed that only 17 (22.7%) ependymomas progressed. The 5-year local tumor control (5-yrs-LTC) rate for all ependymomas was 78.1%, with a lower rate of 59.6% observed in the pediatric cohort and a higher rate of 90.2% in adult patients. For ependymomas classified as WHO grade II, the 5-yrs-LTC rate was 85.9%, whereas it was 58.5% for those classified as WHO grade III. The 5-year overall survival (5-yrs-OS) rate was 73.6% for all patients, with significantly higher rates observed in pediatric patients (94.7%) than in adult patients (41%). The 5-yrs-OS rate was 100% for patients with WHO grade II tumors, whereas it decreased significantly to 35.9% for patients with WHO grade III ependymomas. The 5-year progression-free survival (5-yrs-PFS) rate was 68.5% for all patients, with higher rates observed in pediatric patients (78.3%) than in adult patients (49.2%). The 5-yrs-PFS rate for patients with WHO grade II lesions was 88.8%, whereas it was significantly lower at 32.6% for patients with WHO grade III tumors. Stereotactic radiosurgery (SRS) was effective in improving tumor-associated symptoms in 29 (85.3%) patients with 62 (82.7%) symptomatic ependymomas. These symptoms included headache, back pain, dizziness, nausea, vomiting, cranial nerve palsy, ataxia, motor impairment, sensory deficit, seizures, and weight loss. Notably, no patients developed adverse radiation effects. CONCLUSION CyberKnife SRS is a safe and effective treatment for ependymoma in both adults and children, with potential for significant improvements in tumor-related symptoms. Our study supports its use as a minimally invasive alternative to surgery, warranting further investigation.

Abstract INTRODUCTION Intracranial hemangioblastoma is a rare neoplasm that poses significant challenges in clinical management. Hemangioblastomas are characterized by unique radiological features into cystic or solid tumors. Out study aims to evaluate the role of SRS in the management of cystic and solid hemangioblastomas in a single institution setting. METHODS We conducted a retrospective analysis of clinical and radiological outcomes of patients with intracranial hemangioblastomas treated with CyberKnife SRS at our institute between 1998 and 2023. The follow-up data were available for 93 intracranial hemangioblastomas in 23 patients. Ten (43.5%) patients presented with 23 (25.6%) cystic hemangioblastomas, while 13 (56.5%) patients had 70 (75.3%) solid hemangioblastomas at the time of SRS treatment. The median age was 36 years and the median tumor volume accounted for 0.43 cc. The SRS was administered with the median single-fraction equivalent dose (SFED) of 20 Gy at the 77% of the median isodose line. RESULTS At a one-year follow-up, 11 initially solid hemangioblastomas developed cystic formation, resulting in a total of 34 (36.6%) cystic hemangioblastomas and 59 (63.4%) solid hemangioblastomas across 13 and 10 patients, respectively. Among these, 84.6% exhibited peritumoral edema prior to the onset of cystic formation. For 37 solid hemangioblastomas accompanied by peritumoral edema, SRS was administered before cystic transformation, remaining solid throughout the latest follow-up. Over a median follow-up period of 59 months (range: 3-260), 6 (17.6%) cystic and 13 (22%) solid hemangioblastomas progressed. The 5-year local tumor control (LTC) rate for intracranial hemangioblastomas was 84.7%, with 97% and 76.9% in cystic and solid lesions, respectively. CONCLUSION Our study illustrates the largest single-institutional long-term retrospective analysis of intracranial hemangioblastomas treated with SRS to date. Early SRS treatment at the time of edema may prevent cystic hemangioblastoma development and provides durable treatment outcomes for patients with both cystic and solid hemangioblastomas in long-term.

To determine the efficacy of stereotactic radiosurgery (SRS) in treating patients with brain metastases (BMs), a network meta-analysis (NMA) of randomized controlled trials (RCTs) and a direct comparison of cohort studies were performed. Relevant literature regarding the effectiveness of SRS alone and in combination with wholebrain radiotherapy (WBRT) and surgery was retrieved using systematic database searches up to April 2019. The patterns of overall survival (OS), one-year OS, progression-free survival (PFS), one-year local brain control (LBC), one-year distant brain control (DBC), neurological death (ND), and complication rate were analyzed. A total of 18 RCTs and 37 cohorts were included in the meta-analysis. Our data revealed that SRS carried a better OS than SRS+WBRT (p = 0.048) and WBRT (p = 0.041). Also, SRS+WBRT demonstrated a significantly improved PFS, LBC, and DBC compared to WBRT alone and SRS alone. Finally, SRS achieved the same LBC as high as surgery, but intracranial relapse occurred considerably more frequently in the absence of WBRT. However, there were not any significant differences in ND and toxicities between SRS and other groups. Therefore, SRS alone may be a better alternative since increased patient survival may outweigh the increased risk of brain tumor recurrence associated with it.

BACKGROUND: Trigeminal neuralgia (TN) is a paroxysmal, unilateral, brief, shock-like pain in >= 1 divisions of the trigeminal nerve. It can result from multiple causes; however, TN secondary to stroke is very rare. METHODS: We present the case of TN secondary to pontine infarction treated with incremental doses of neuropathic pain medication for >5 years before conservative management failed. He was then treated with stereotactic radiosurgery (SRS). Additionally, we conducted a systematic review using standard PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for all the cases of TN with brainstem stroke from 1976 to 2022. RESULTS: Our patient was an 82-year-old man. Magnetic resonance imaging demonstrated a pontine lesion consistent with stroke. The Barrow Neurological Institute (BNI) score at presentation was 5. He received a marginal dose of 60 Gy to the 80% isodose line in a single fraction to a volume of 0.05 cm(3). The immediate post-treatment BNI score was 0 and remained at 0 for 3 months, when he experienced recurrence. The recurrence was treated with oxcarbazepine. His pain remained well controlled with a lower dose of oxcarbazepine, and he had no adverse effects at 1 year of follow-up with a BNI score of 3. The systemic review identified 21 case reports with a combined cohort of 25 patients with TN secondary to stroke. Only 3 patients were treated with SRS, 2 of whom reported symptom improvement at 6 months and 8 months of follow-u p with no adverse events. CONCLUSIONS: Our case and literature review demonstrate durable and effective treatment with SRS, which can be considered a safe and effective treatment option for patients with stroke-associated TN.

BACKGROUND:Choroid plexus papillomas (CPPs) are rare intraventricular brain tumors derived from the epithelium of the choroid plexus. Gross total resection has traditionally been considered curative, but residual tumor or recurrence remains possible. Stereotactic radiosurgery (SRS) has become a more important strategy for subtotally resected and recurrent tumors. The evidence-based rationale of SRS treatment for residual or recurrent CPP in adult patients is still lacking because of the rarity of the disease. METHODS:We retrospectively reviewed the cases of histopathologically confirmed patients with residual or recurrent CPP treated with SRS at our institute in the adult population between 2005 and 2022. Three patients, with 5 lesions, were identified, with a median age of 63 years. Patients presented initially with hydrocephalus-related symptoms, although ventriculomegaly was noted in only 1 patient radiographically. The tumor location was most commonly in the fourth ventricle or along the foramen of Luschka. Treatment was delivered in a single fraction in 4 lesions and in 3 fractions in 1 patient. The median follow-up was 26 months. RESULTS:The local tumor control rate for the lesions was 80%. One patient developed a new lesion outside the SRS field, and 1 lesion developed progression without the need for subsequent treatment. There was no significant shrinkage of the lesions radiographically. None of the patients showed radiation-related adverse events. No patients required surgical management after SRS treatment at our institution. Based on the literature review, our case series was the second largest retrospective series from a single institution on SRS for recurrent or residual CPP. CONCLUSIONS:SRS for patients with recurrent or residual CPP was a safe and effective treatment modality in this case series. Larger studies are encouraged to validate the role of SRS in the treatment of recurrent or residual CPP.

Purpose Belzutifan is a Hypoxia Inducible Factor 2-alpha inhibitor approved in 2021 by the FDA for the treatment of renal cell carcinoma (RCC) in patients with Von-Hippel Landau (VHL) disease. These patients can also present with central nervous system (CNS) hemangioblastomas (HBs). We aim to study the effectiveness and adverse effects of belzutifan for CNS HBs, by reporting our preliminary institutional experience. Methods We present a series of VHL patients with CNS HBs undergoing treatment with belzutifan for RCC. All the included patients met the RECIST inclusion criteria. The clinical and radiological outcome measures included: Objective response rate (ORR), time-to-response (TTR), adverse events (AE), and patient response. Patient response was classified as partial response (PR), complete response (CR), progressive disease (PD), or stable disease (SD). Results Seven patients with 25 HBs were included in our study. A belzutifan dose of 120 mg/day PO was administered for a median of 13 months (range 10–17). Median follow up time was 15 months (range 10–24). An ORR of 71% was observed. The median TTR was 5 months (range: 1–10). None of the patients showed CR, while 5 patients (71.4%) showed PR and 2 (28.5%) showed SD. Among patients with SD the maximum tumor response was 20% [increase/decrease] of the lesion diameter. All the patients experienced decreased hemoglobin concentration, fatigue, and dizziness. None of the patients experienced severe anemia (grade 3–4 CTCAE). Conclusion Belzutifan appears to be an effective and safe treatment for CNS hemangioblastoma in VHL patients. Further clinical trials to assess the long-term effectiveness of the medication are required.

OBJECTIVE:Brain metastases (BMs) secondary to sarcoma are rare, and their incidence ranges from 1% to 8% of all bone and soft tissue sarcomas. Although stereotactic radiosurgery (SRS) is widely used for BMs, only a few papers have reported on SRS for sarcoma metastasizing to the brain. The purpose of this study was to evaluate the safety and effectiveness of SRS for sarcoma BM.METHODS:The authors retrospectively reviewed the clinical and radiological outcomes of patients with BM secondary to histopathologically confirmed sarcoma treated with SRS, either as primary treatment or as adjuvant therapy after surgery, at their institution between January 2005 and September 2022. They also compared the outcomes of patients with hemorrhagic lesions and of those without.RESULTS:Twenty-three patients (9 females) with 150 BMs secondary to sarcoma were treated with CyberKnife SRS. Median age at the time of treatment was 48.22 years (range 4-76 years). The most common primary tumor sites were the heart, lungs, uterus, upper extremities, chest wall, and head and neck. The median Karnofsky Performance Status on presentation was 73.28 (range 40-100). Eight patients underwent SRS as a primary treatment and 15 as adjuvant therapy to the resection cavity. The median tumor volume was 24.1 cm3 (range 0.1-150.3 cm3), the median marginal dose was 24 Gy (range 18-30 Gy) delivered in a median of 1 fraction (range 1-5) to a median isodose line of 76%. The median follow-up was 8 months (range 2-40 months). Median progression-free survival and overall survival were 5.3 months (range 0.4-32 months) and 8.2 months (range 0.1-40), respectively. The 3-, 6-, and 12-month local tumor control (LTC) rates for all lesions were respectively 78%, 52%, and 30%. There were no radiation-induced adverse effects. LTC at the 3-, 6-, and 12-month follow-ups was better in patients without hemorrhagic lesions (100%, 70%, and 40%, respectively) than in those with hemorrhagic lesions (68%, 38%, and 23%, respectively).CONCLUSIONS:SRS, both as a primary treatment and as adjuvant therapy to the resection cavity after surgery, is a safe and relatively effective treatment modality for sarcoma BMs. Nonhemorrhagic lesions show better LTC than hemorrhagic lesions. Larger studies aiming to validate these results are encouraged.