Recurrent choroid plexus carcinoma treated with CyberKnife radiosurgery: illustrative case.

BACKGROUND: Choroid plexus carcinomas (CPCs) are rare malignant brain tumors primarily affecting children younger than 2 years old. These tumors originate from the choroid plexus epithelium and are a subtype of choroid plexus tumors, which account for 1%-4% of pediatric brain tumors. Although CPCs often show a notably high recurrence rate after surgery, the standard treatment approach remains gross-total resection (GTR) of the tumor, given the lack of clinical data supporting the effectiveness of adjunct treatment options such as radiotherapy or chemotherapy. OBSERVATIONS: A 16-year-old female with a history of a recurrent cranial CPC resistant to surgery and radiotherapy was treated with CyberKnife stereotactic radiosurgery (SRS), following resection. The procedures successfully maintained local disease control for 41 months; however, there was a subsequent recurrence, ultimately leading to the death of the patient. LESSONS: CPC treatment remains challenging. SRS can be used as a viable adjunct to surgery, which remains the gold standard, although it can also be considered for nonsurgical candidates or when GTR cannot be achieved. Nevertheless, it is crucial to conduct additional research to explore diverse approaches for radiosurgery, including its role as the primary treatment modality versus its combination with surgery, radiotherapy, or chemotherapy. https://thejns.org/doi/10.3171/CASE23748.

Primary Stereotactic Body Radiotherapy for Spinal Bone Metastases From Lung Adenocarcinoma.

OBJECTIVE: This study aimed to assess the results of primary stereotactic body radiotherapy (SBRT) for spinal bone metastases (SBM) originating from lung adenocarcinoma (ADC). We considered the revised Tokuhashi score (rTS), Spinal Instability Neoplastic Score (SINS), and genetic characteristics. METHODS: We examined adult patients with lung ADC who underwent primary SBRT (using the CyberKnife System) for SBM between March 2012 and January 2023. RESULTS: We analyzed data from 99 patients, covering 152 SBM across 194 vertebrae. The overall local control (LC) rate was 77.6% for SBM from lung ADC, with a LC rate of 90.7% at 1 year. The median period for local progression (LP) occurrence was recorded at 10.0 (3-52) months. Additionally, Asian patients demonstrated higher LC rates than White patients. Utilizing the rTS and SINS as predictive tools, we revealed that a poor survival prognosis and an unstable spinal structure were associated with increased rates of LP. Furthermore, the presence of osteolytic bone destructions and pain complaints were significantly correlated with the occurrence of LP. In the cohort of this study, 108 SBM underwent analysis to determine the expression levels of programmed cell death ligand 1 (PD-L1). Additionally, within this group, 60 showed mutations in the epidermal growth factor receptor (EGFR) alongside PD-L1 expression. Nevertheless, these genetic differences did not result in statistically significant differences in the LC rate. CONCLUSION: The one-year LC rate for primary SBRT targeting SBM from lung ADC stood at 90.7%, particularly with the use of the CyberKnife System. Patients achieving LC exhibited significantly longer survival times compared to those with LP.

The Role of CyberKnife Stereotactic Radiosurgery in Recurrent Cranial Medulloblastomas across Pediatric and Adult Populations.

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.

Stereotactic radiosurgery for facial nerve hemangioma: Case report and systematic review.

BACKGROUND: Facial nerve hemangiomas (FNHs) are rare tumors that primarily occur near the geniculate ganglion in the temporal bone. Despite their rarity, they can cause significant facial nerve dysfunction. The optimal management approach for FNHs remains uncertain, with surgery being the mainstay but subject to debate regarding the extent of resection and preservation of the facial nerve. METHODS: Systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We queried the PubMed/Medline (accessed on 5 March 2024) electronic database using combinations of the following search terms and words text: "geniculate ganglion hemangioma", "ganglional hemangioma", "hemangioma of the facial nerve", "facial hemangioma", and "intratemporal hemangioma". RESULTS: We identified a total of 30 literatures (321 patients). The most common site involved for the facial nerve hemangioma was the geniculate ganglion area followed by internal auditory canal, tympanic segment, labyrinthine segment and mastoid involvement. All patients were treated with conservative management or surgery. We report a 48-year-old female patient with HB grade 2 facial palsy and hemifacial spasm underwent SRS using Cyberknife technology. The treatment targeted the FNH in the left internal acoustic canal near the geniculate ganglion. Six months post-treatment, clinical improvement was evident, and lesion control was confirmed in a follow-up brain MRI. CONCLUSION: The rarity of FNHs contributes to the lack of consensus on optimal management. This illustrative case demonstrates the feasibility of SRS as a standalone treatment for FNHs.

CyberKnife stereotactic radiosurgery for extramedullary plasmacytoma in the external auditory canal: illustrative case.

BACKGROUND: Plasmacytoma, a rare plasma cell disorder, often presents as a solitary or multiple tumors within the bone marrow or soft tissues, typically associated with multiple myeloma. Extramedullary plasmacytomas (EMPs), particularly those located in the external auditory canal (EAC), are exceedingly rare and pose significant treatment challenges given their location, anatomical complexity, and high risk of recurrence. OBSERVATIONS: The authors report the case of a 72-year-old male with a history of multiple myeloma, presenting with recurrent left EAC plasmacytoma. After initial conventional radiotherapy for the lesion, a recurrence was documented in 7 years. The patient subsequently underwent stereotactic radiosurgery, which proved successful, leading to complete resolution of the lesion without any long-term adverse effects or radiation-related complications over a 45-month period. LESSONS: This case is a unique instance of utilizing stereotactic radiosurgery for recurrent EMP in the EAC, highlighting its potential as an effective approach in managing complex plasmacytomas.

Stereotactic Radiosurgery for Ependymoma in Pediatric and Adult Patients: A Single-Institution Experience.

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.

Dosimetric Comparison of Dedicated Radiosurgery Platforms for the Treatment of Essential Tremor: Technical Report.

Essential tremor (ET) is one of the most common adult movement disorders. As the worldwide population ages, the incidence and prevalence of ET is increasing. Although most cases can be managed conservatively, there is a subset of ET that is refractory to medical management. By virtue of being "reversible", deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus is one commonly accepted intervention. As an alternative to invasive and expensive DBS, there has been a renaissance in treating ET with lesion-based approaches, spearheaded most recently by high-intensity focused ultrasound (HIFU), the hallmark of which is that it is non-invasive. Meanwhile, stereotactic radiosurgical (SRS) lesioning of VIM represents another time-honored lesion-based non-invasive treatment of ET, which is especially well suited for those patients that cannot tolerate open neurosurgery and is now also getting a "second look". While multiple SRS platforms have been and continue to be used to treat ET, there is little in the way of dosimetric comparison between different technologies. In this brief technical report we compare the dosimetric profiles of three major radiosurgical platforms (Gamma Knife, CyberKnife Robotic Radiosurgery, and Zap-X Gyroscopic Radiosurgery (GRS)) for the treatment of ET. In general, the GRS and Gamma Knife were shown to have the best theoretical dosimetric profiles for VIM lesioning. Nevertheless the relevance of such superiority to clinical outcomes requires future patient studies.

Automatic Segmentation of Vestibular Schwannomas: A Systematic Review.

BACKGROUND: Vestibular schwannomas (VSs) are benign tumors often monitored over time, with measurement techniques for assessing growth rates subject to significant interobserver variability. Automatic segmentation of these tumors could provide a more reliable and efficient for tracking their progression, especially given the irregular shape and growth patterns of VS. METHODS: Various studies and segmentation techniques employing different Convolutional Neural Network architectures and models, such as U-Net and convolutional-attention transformer segmentation, were analyzed. Models were evaluated based on their performance across diverse datasets, and challenges, including domain shift and data sharing, were scrutinized. RESULTS: Automatic segmentation methods offer a promising alternative to conventional measurement techniques, offering potential benefits in precision and efficiency. However, these methods are not without challenges, notably the "domain shift" that occurs when models trained on specific datasets underperform when applied to different datasets. Techniques such as domain adaptation, domain generalization, and data diversity were discussed as potential solutions. CONCLUSIONS: Accurate measurement of VS growth is a complex process, with volumetric analysis currently appearing more reliable than linear measurements. Automatic segmentation, despite its challenges, offers a promising avenue for future investigation. Robust well-generalized models could potentially improve the efficiency of tracking tumor growth, thereby augmenting clinical decision-making. Further work needs to be done to develop more robust models, address the domain shift, and enable secure data sharing for wider applicability.

Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis.

PURPOSE: To determine whether sampling of the disc or bone is more likely to yield positive tissue culture results in patients with vertebral discitis and osteomyelitis (VDO). MATERIALS AND METHODS: Retrospective review was performed of consecutive patients who underwent vertebral disc or vertebral body biopsy at a single institution between February 2019 and May 2023. Inclusion criteria were age ≥18 years, presumed VDO on spinal magnetic resonance (MR) imaging, absence of paraspinal abscess, and technically successful percutaneous biopsy with fluoroscopic guidance. The primary outcome was a positive biopsy culture result, and secondary outcomes included complications such as nerve injury and segmental artery injury. RESULTS: Sixty-six patients met the inclusion criteria; 36 patients (55%) underwent disc biopsy, and 30 patients (45%) underwent bone biopsy. Six patients required a repeat biopsy for an initially negative culture result. No significant demographic, laboratory, antibiotic administration, or pain medication use differences were observed between the 2 groups. Patients who underwent bone biopsy were more likely to have a history of intravenous drug use (26.7%) compared with patients who underwent disc biopsy (5.5%; P = .017). Positive tissue culture results were observed in 41% of patients who underwent disc biopsy and 15% of patients who underwent bone biopsy (P = .016). No vessel or nerve injuries were detected after procedure in either group. CONCLUSIONS: Percutaneous disc biopsy is more likely to yield a positive tissue culture result than vertebral body biopsy in patients with VDO.

Therapeutic approaches for spinal synovial sarcoma: a comprehensive review of the literature.

OBJECTIVE: Synovial sarcoma (SS) is a relatively rare type of soft-tissue sarcoma that is commonly treated with surgery, radiation, chemotherapy, and palliative care. Stereotactic radiosurgery (SRS) is an emerging approach that shows promise in treating CNS conditions, but it has not been studied for SS. The authors present a systematic review that explores the effectiveness of different treatments, with a focus on SRS, for managing spinal SS. METHODS: A systematic PubMed search was conducted that covered studies from 1964 to 2022, yielding 70 relevant studies. Inclusion criteria encompassed primary and metastatic spinal SS, various treatment modalities, patient age 17 years or older, English-language studies, retrospective series, and case reports. Based on these criteria, 26 studies were included in this review and 44 were excluded. RESULTS: Of the included studies, 15 patients from 9 studies were treated with surgical intervention followed by both conventional radiotherapy (RT) and chemotherapy, 10 patients from 10 studies were treated with surgery followed by RT, 5 studies comprising 8 patients were exclusively treated with surgery, 5 cases in 3 studies were treated with surgery plus concomitant chemotherapy, 4 patients in 2 studies were treated with SRS, and only 1 study reported treatment without surgery and with chemotherapy and RT. The median progression-free survival and overall survival periods observed in the SRS-treated patients were 37 months and 60 months, respectively, which were higher than those of any other treatment method or combination used. CONCLUSIONS: The authors' study offers a thorough review of spinal SS treatments. They are hopeful that this will aid clinicians in informed decision-making for better patient outcomes.

Stereotactic Radiosurgery for Cranial and Spinal Hemangioblastomas: A Single-Institution Retrospective Series.

BACKGROUND AND OBJECTIVES: Stereotactic radiosurgery (SRS) has been an attractive treatment modality for both cranial and spinal hemangioblastomas, especially for multiple lesions commonly associated with von Hippel-Lindau (VHL) disease. This study aims to provide the largest long-term analysis of treatment efficacy and adverse effects of SRS for cranial and spinal hemangioblastomas at a single institution. METHODS: We evaluated the clinical and radiological outcomes of patients with hemangioblastomas treated with CyberKnife SRS at our institute from 1998 to 2022. The follow-up data were available for 135 hemangioblastomas in 35 patients. Twenty-eight patients had 123 hemangioblastomas associated with VHL, and 7 had 12 sporadic hemangioblastomas. The median age was 36 years, and the median tumor volume accounted for 0.4 cc. The SRS was administered with the median single-fraction equivalent dose of 18 Gy to the 77% median isodose line. RESULTS: At a median follow-up of 57 months (range: 3-260), only 20 (16.2%) of the VHL-associated and 1 (8.3%) sporadic hemangioblastomas progressed. The 5-year local tumor control rate was 91.3% for all hemangioblastomas, 91.7% among the sporadic lesions, and 92.9% in patients with VHL. SRS improved tumor-associated symptoms of 98 (74.8%) of 131 symptomatic hemangioblastomas, including headache, neck pain, dizziness, visual disturbances, dysesthesia, ataxia, motor impairment, seizures, and dysphagia. Two patients developed radiation necrosis (5.7%), and 1 of them required surgical resection. CONCLUSION: SRS is a safe and effective treatment option for patients with hemangioblastomas in critical locations, such as the brainstem, cervicomedullary junction, and spinal cord, and in patients with multiple hemangioblastomas associated with VHL disease.

Surgery and stereotactic radiosurgery for spinal leiomyosarcoma: a single-institution retrospective series and systematic review.

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.

The outcome of central nervous system hemangioblastomas in Von Hippel-Lindau (VHL) disease treated with belzutifan: a single-institution retrospective experience.

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.

Spinal metastases of pineal region glioblastoma with primitive neuroectodermal features highlighting the importance of molecular diagnoses: illustrative case.

BACKGROUND: Glioblastoma (GBM) is the most common primary brain tumor with poor patient prognosis. Spinal leptomeningeal metastasis has been rarely reported, with long intervals between the initial discovery of the primary tumor in the brain and eventual spine metastasis. OBSERVATIONS: Here, the authors present the case of a 51-year-old male presenting with 7 days of severe headache, nausea, and vomiting. Magnetic resonance imaging of the brain and spine demonstrated a contrast-enhancing mass in the pineal region, along with spinal metastases to T8, T12, and L5. Initial frozen-section diagnosis led to the treatment strategy for medulloblastoma, but further molecular analysis revealed characteristics of isocitrate dehydrogenase-wild type, grade 4 GBM. LESSONS: Glioblastoma has the potential to show metastatic spread at the time of diagnosis. Spinal imaging should be considered in patients with clinical suspicion of leptomeningeal spread. Furthermore, molecular analysis should be confirmed following pathological diagnosis to fine-tune treatment strategies.

Practical Guideline for Prevention of Patchy Hair Loss following CyberKnife Stereotactic Radiosurgery for Calvarial or Scalp Tumors: Retrospective Analysis of a Single Institution Experience.

INTRODUCTION: Patchy alopecia is a common adverse effect of stereotactic radiosurgery (SRS) on the calvarium and/or scalp, yet no guidelines exist for its prevention. This study aims to investigate the incidence and outcomes of patchy alopecia following SRS for patients with calvarial or scalp lesions and establish preventive guidelines. METHODS: The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months. RESULTS: Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found. CONCLUSION: In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.

Stereotactic Radiosurgery for Contrast-Enhancing Satellite Nodules in Recurrent Glioblastoma: A Rare Case Series From a Single Institution.

Introduction Glioblastoma (GBM) is the most common malignant adult brain tumor and is invariably fatal. The standard treatment for GBM involves resection where possible, followed by chemoradiation per Stupp's protocol. We frequently use stereotactic radiosurgery (SRS) as a single-fraction treatment for small (volume ≤ 1cc) nodular recurrent GBM to the contrast-enhancing target on T1 MRI scan. In this paper, we aimed to evaluate the safety and efficacy of SRS for patients with contrast-enhancing satellite nodules in recurrent GBM. Methods This retrospective study analyzed the clinical and radiological outcomes of five patients who underwent CyberKnife (Accuray Inc., Sunnyvale, California) SRS at the institute between 2013 and 2022. Results From 96 patients receiving SRS for GBM, five (four males, one female; median age 53) had nine distinct new satellite lesions on MRI, separate from their primary tumor beds. Those nine lesions were treated with a median margin dose of 20 Gy in a single fraction. The three-, six, and 12-month local tumor control rates were 77.8%, 66.7%, and 26.7%, respectively. Median progression-free survival (PFS) was seven months, median overall survival following SRS was 10 months, and median overall survival (OS) was 35 months. Interestingly, the only lesion that did not show radiological progression was separate from the T2-fluid attenuated inversion recovery (FLAIR) signal of the main tumor. Conclusion Our SRS treatment outcomes for recurrent GBM satellite lesions are consistent with existing findings. However, in a unique case, a satellite nodule distinct from the primary tumor's T2-FLAIR signal and treated with an enlarged target volume showed promising control until the patient's demise. This observation suggests potential research avenues, given the limited strategies for 'multicentric' GBM lesions.

Optimizing the synergy between stereotactic radiosurgery and immunotherapy for brain metastases.

Solid tumors metastasizing to the brain are a frequent occurrence with an estimated incidence of approximately 30% of all cases. The longstanding conventional standard of care comprises surgical resection and whole-brain radiotherapy (WBRT); however, this approach is associated with limited long-term survival and local control outcomes. Consequently, stereotactic radiosurgery (SRS) has emerged as a potential alternative approach. The primary aim of SRS has been to improve long-term control rates. Nevertheless, rare observations of abscopal or out-of-field effects have sparked interest in the potential to elicit antitumor immunity via the administration of high-dose radiation. The blood-brain barrier (BBB) has traditionally posed a significant challenge to the efficacy of systemic therapy in managing intracranial metastasis. However, recent insights into the immune-brain interface and the development of immunotherapeutic agents have shown promise in preclinical and early-phase clinical trials. Researchers have investigated combining immunotherapy with SRS to enhance treatment outcomes in patients with brain metastasis. The combination approach aims to optimize long-term control and overall survival (OS) outcomes by leveraging the synergistic effects of both therapies. Initial findings have been encouraging in the management of various intracranial metastases, while further studies are required to determine the optimal order of administration, radiation doses, and fractionation regimens that have the potential for the best tumor response. Currently, several clinical trials are underway to assess the safety and efficacy of administering immunotherapeutic agents concurrently or consecutively with SRS. In this review, we conduct a comprehensive analysis of the advantages and drawbacks of integrating immunotherapy into conventional SRS protocols for the treatment of intracranial metastasis.

Stereotactic Radiosurgery for Medically Refractory Trigeminal Neuralgia Secondary to Stroke: A Systematic Review and Clinical Case Presentation.

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 cm3. 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-up 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.

Stereotactic radiosurgery for sarcoma metastases to the brain: a single-institution experience.

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.