Up-front single-session radiosurgery for large brain metastases-volumetric responses and outcomes.

BACKGROUND: Patients presenting with large brain metastases (LBM) pose a management challenge to the multidisciplinary neuro-oncologic team. Treatment options include surgery, whole-brain or large-field radiation therapy (WBRT), stereotactic radiosurgery (SRS), or a combination of these. OBJECTIVE: To determine if corticosteroid therapy followed by SRS allows for efficient minimally invasive care in patients with LBMs not compromised by mass effect. METHODS: We analyzed the change in tumor volume to determine the efficacy of single-session SRS in the treatment of LBM in comparison to other treatment modalities. Twenty-nine patients with systemic cancer and brain metastasis (≥ 2.7 cm in greatest diameter) who underwent single-session SRS were included. RESULTS: Among 29 patients, 69% of patients had either lung, melanoma, or breast cancer. The median initial tumor size (maximal diameter) was 32 mm (range 28-43), and the median initial tumor volume was 9.56 cm3 (range 1.56-25.31). The median margin dose was 16 Gy (range 12-18). The average percent decrease in tumor volume compared to pre-SRS volume was 55% on imaging at 1-2 months, 58% at 3-5 months, 64% at 6-8 months, and 57% at > 8 months. There were no adverse events immediately following SRS. Median corticosteroid use after SRS was 21 days. Median survival after radiosurgery was 15 months. CONCLUSION: Initial high-dose corticosteroid therapy followed by prompt single-stage SRS is a safe and efficacious method to manage patients with LBMs (defined as ≥ 2.7 cm).

Significant survival improvements for patients with melanoma brain metastases: can we reach cure in the current era?

PURPOSE: New therapies for melanoma have been associated with increasing survival expectations, as opposed to the dismal outcomes of only a decade ago. Using a prospective registry, we aimed to define current survival goals for melanoma patients with brain metastases (BM), based on state-of-the-art multimodality care. METHODS: We reviewed 171 melanoma patients with BM receiving stereotactic radiosurgery (SRS) who were followed with point-of-care data collection between 2012 and 2020. Clinical, molecular and imaging data were collected, including systemic treatment and radiosurgical parameters. RESULTS: Mean age was 63 ± 15 years, 39% were female and 29% had BRAF-mutated tumors. Median overall survival after radiosurgery was 15.7 months (95% Confidence Interval 11.4-27.7) and 25 months in patients managed since 2015. Thirty-two patients survived [Formula: see text] 5 years from their initial SRS. BRAF mutation-targeted therapies showed a survival advantage in comparison to chemotherapy (p = 0.009), but not to immunotherapy (p = 0.09). In a multivariable analysis, both immunotherapy and the number of metastases at 1st SRS were predictors of long-term survival ([Formula: see text] 5 years) from initial SRS (p = 0.023 and p = 0.018, respectively). Five patients (16%) of the long-term survivors required no active treatment for [Formula: see text] 5 years. CONCLUSION: Long-term survival in patients with melanoma BM is achievable in the current era of SRS combined with immunotherapies. For those alive [Formula: see text] 5 years after first SRS, 16% had been also off systemic or local brain therapy for over 5 years. Given late recurrences of melanoma, caution is warranted, however prolonged survival off active treatment in a subset of our patients raises the potential for cure.

Individualized clinical management of patients at risk for Alzheimer's dementia.

INTRODUCTION: Multidomain intervention for Alzheimer's disease (AD) risk reduction is an emerging therapeutic paradigm. METHODS: Patients were prescribed individually tailored interventions (education/pharmacologic/nonpharmacologic) and rated on compliance. Normal cognition/subjective cognitive decline/preclinical AD was classified as Prevention. Mild cognitive impairment due to AD/mild-AD was classified as Early Treatment. Change from baseline to 18 months on the modified Alzheimer's Prevention Cognitive Composite (primary outcome) was compared against matched historical control cohorts. Cognitive aging composite (CogAging), AD/cardiovascular risk scales, and serum biomarkers were secondary outcomes. RESULTS: One hundred seventy-four were assigned interventions (age 25-86). Higher-compliance Prevention improved more than both historical cohorts (P = .0012, P < .0001). Lower-compliance Prevention also improved more than both historical cohorts (P = .0088, P < .0055). Higher-compliance Early Treatment improved more than lower compliance (P = .0007). Higher-compliance Early Treatment improved more than historical cohorts (P < .0001, P = .0428). Lower-compliance Early Treatment did not differ (P = .9820, P = .1115). Similar effects occurred for CogAging. AD/cardiovascular risk scales and serum biomarkers improved. DISCUSSION: Individualized multidomain interventions may improve cognition and reduce AD/cardiovascular risk scores in patients at-risk for AD dementia.

The clinical practice of risk reduction for Alzheimer's disease: A precision medicine approach.

Like virtually all age-related chronic diseases, late-onset Alzheimer's disease (AD) develops over an extended preclinical period and is associated with modifiable lifestyle and environmental factors. We hypothesize that multimodal interventions that address many risk factors simultaneously and are individually tailored to patients may help reduce AD risk. We describe a novel clinical methodology used to evaluate and treat patients at two Alzheimer's Prevention Clinics. The framework applies evidence-based principles of clinical precision medicine to tailor individualized recommendations, follow patients longitudinally to continually refine the interventions, and evaluate N-of-1 effectiveness (trial registered at ClinicalTrials.gov NCT03687710). Prior preliminary results suggest that the clinical practice of AD risk reduction is feasible, with measurable improvements in cognition and biomarkers of AD risk. We propose using these early findings as a foundation to evaluate the comparative effectiveness of personalized risk management within an international network of clinician researchers in a cohort study possibly leading to a randomized controlled trial.

Ultra-Early Hemostatic Therapy for Acute Intracerebral Hemorrhage: An Updated Review.

Intracerebral hemorrhage (ICH) is the second most common type of stroke, accounting for approximately 10-20% of all strokes, and is linked to severe neurological disability and death. Since the most accurate predictor of outcome in patients with ICH is hematoma volume, there is a great need for pharmacologic therapy that can reduce hematoma expansion and resultant mass effect and edema. This is especially critical within the ultra-early window of 3-4 hours after the presentation. Hemostatic therapies are exceptionally important for those patients taking antiplatelet or anticoagulant medications to reverse the effects of these medications and therefore prevent hematoma expansion. Furthermore, the recent publication of the 2023 Guideline for the Management of Patients with Aneurysmal Subarachnoid Hemorrhage by the American Heart Association/American Stroke Association, the first update to the guidelines since 2012, underscores the importance of optimizing anticoagulation reversal for this population. The purpose of this selective, nonsystematic review is to examine current literature regarding the use of hemostatic therapies in ICH, with particular attention paid to antiplatelet, anticoagulation, and antifibrinolytic therapies.

Virtual Neurosurgery Education for Medical Students without Home Residency Programs: A Survey of 2020 Virtual Neurosurgery Training Camp Attendees.

OBJECTIVE: To examine the perceived effectiveness of the virtual neurosurgery training camps (VNTC) among medical students with (HP) and without (NHP) home neurosurgery residency programs. METHODS: A survey assessing demographics, baseline interests, and ratings of usefulness and interest of programming was sent to attendees after the VNTC. Ratings were quantified on modified 7-point Likert scales. Ratings were compared between attendees HP and NHP neurosurgery residency programs using Wilcoxon sum-rank or χ2 tests. A P value of 0.05 determined significance. RESULTS: There were 119 respondents, with 80 (67.2%) HP and 39 (32.8%) NHP students. Differences were observed between the groups for medical school type (P = 0.002), highest degree achieved (P = 0.030), previous participation in a Medical Student Neurosurgery Training Center event (P = 0.004), having a neurosurgery interest group (P < 0.001), and primary reason for VNTC attendance (P = 0.028). Increased interest in peripheral nerve neurosurgery was greater for the NHP (P = 0.047) but not neurosurgery or other subspecialties. A significant difference in usefulness of the different VNTC sessions was observed (P = 0.002), whereas none was seen in willingness to pursue neurosurgery (P = 0.33), likelihood of taking a year off (P = 0.44), and preparedness for subinternships (P = 0.57) or applications (P = 0.77). CONCLUSIONS: The 2020 VNTC benefited both HPO and NHP medical students, but there were differences in perceived usefulness of virtual education. Future initiatives should continue to be tailored toward disadvantaged students.

A novel variant of the aortic arch great vessels.

Congenital variants of the aortic arch are important to recognize not only for their association with congenital heart disease, vascular rings, and chromosomal abnormalities but also for the purposes of neurointerventional angiography. While many different variants have been reported in the literature, we present two rare cases of an aortic arch variant that, to the best of our knowledge, has not yet been described in the literature- an anteriorly-directed, independent common origin of both carotid arteries from the ascending aorta, with separate subclavian artery trunks originating from the arch.

Dose to neuroanatomical structures surrounding pituitary adenomas and the effect of stereotactic radiosurgery on neuroendocrine function: an international multicenter study.

OBJECTIVE: Stereotactic radiosurgery (SRS) provides a safe and effective therapeutic modality for patients with pituitary adenomas. The mechanism of delayed endocrine deficits based on targeted radiation to the hypothalamic-pituitary axis remains unclear. Radiation to normal neuroendocrine structures likely plays a role in delayed hypopituitarism after SRS. In this multicenter study by the International Radiosurgery Research Foundation (IRRF), the authors aimed to evaluate radiation tolerance of structures surrounding pituitary adenomas and identify predictors of delayed hypopituitarism after SRS for these tumors. METHODS: This is a retrospective review of patients with pituitary adenomas who underwent single-fraction SRS from 1997 to 2019 at 16 institutions within the IRRF. Dosimetric point measurements of 14 predefined neuroanatomical structures along the hypothalamus, pituitary stalk, and normal pituitary gland were made. Statistical analyses were performed to determine the impact of doses to critical structures on clinical, radiographic, and endocrine outcomes. RESULTS: The study cohort comprised 521 pituitary adenomas treated with SRS. Tumor control was achieved in 93.9% of patients over a median follow-up period of 60.1 months, and 22.5% of patients developed new loss of pituitary function with a median treatment volume of 3.2 cm3. Median maximal radiosurgical doses to the hypothalamus, pituitary stalk, and normal pituitary gland were 1.4, 7.2, and 11.3 Gy, respectively. Nonfunctioning adenoma status, younger age, higher margin dose, and higher doses to the pituitary stalk and normal pituitary gland were independent predictors of new or worsening hypopituitarism. Neither the dose to the hypothalamus nor the ratio between doses to the pituitary stalk and gland were significant predictors. The threshold of the median dose to the pituitary stalk for new endocrinopathy was 10.7 Gy in a single fraction (OR 1.77, 95% CI 1.17-2.68, p = 0.006). CONCLUSIONS: SRS for the treatment of pituitary adenomas affords a high tumor control rate with an acceptable risk of new or worsening endocrinopathy. This evaluation of point dosimetry to adjacent neuroanatomical structures revealed that doses to the pituitary stalk, with a threshold of 10.7 Gy, and doses to the normal gland significantly increased the risk of post-SRS hypopituitarism. In patients with preserved pre-SRS neuroendocrine function, limiting the dose to the pituitary stalk and gland while still delivering an optimal dose to the tumor appears prudent.

Survival and outcomes in patients with ≥ 25 cumulative brain metastases treated with stereotactic radiosurgery.

OBJECTIVE: In the era in which more patients with greater numbers of brain metastases (BMs) are being treated with stereotactic radiosurgery (SRS) alone, it is critical to understand how patient, tumor, and treatment factors affect functional status and overall survival (OS). The authors examined the survival outcomes and dosimetry to critical structures in patients treated with Gamma Knife radiosurgery (GKRS) for ≥ 25 metastases in a single session or cumulatively over the course of their disease. METHODS: A retrospective analysis was conducted at a single institution. The institution's prospective Gamma Knife (GK) SRS registry was queried to identify patients treated with GKRS for ≥ 25 cumulative BMs between June 2013 and April 2020. Ninety-five patients were identified, and their data were used for analysis. Treatment plans for dosimetric analysis were available for 89 patients. Patient, tumor, and treatment characteristics were identified, and outcomes and OS were evaluated. RESULTS: The authors identified 1132 patients with BMs in their institutional registry. Ninety-five patients were treated for ≥ 25 cumulative metastases, resulting in a total of 3596 tumors treated during 373 separate treatment sessions. The median number of SRS sessions per patient was 3 (range 1-12 SRS sessions), with nearly all patients (n = 93, 98%) having > 1 session. On univariate analysis, factors affecting OS in a statistically significant manner included histology, tumor volume, tumor number, diagnosis-specific graded prognostic assessment (DS-GPA), brain metastasis velocity (BMV), and need for subsequent whole-brain radiation therapy (WBRT). The median of the mean WB dose was 4.07 Gy (range 1.39-10.15 Gy). In the top quartile for both the highest cumulative number and highest cumulative volume of treated metastases, the median of the mean WB dose was 6.14 Gy (range 4.02-10.15 Gy). Seventy-nine patients (83%) had all treated tumors controlled at last follow-up, reflecting the high and durable control rate. Corticosteroids for tumor- or treatment-related effects were prescribed in just over one-quarter of the patients. Of the patients with radiographically proven adverse radiation effects (AREs; 15%), 4 were symptomatic. Four patients required subsequent craniotomy for hemorrhage, progression, or AREs. CONCLUSIONS: In selected patients with a large number of cumulative BMs, multiple courses of SRS are feasible and safe. Together with new systemic therapies, the study results demonstrate that the achieved survival rates compare favorably to those of larger contemporary cohorts, while avoiding WBRT in the majority of patients. Therefore, along with the findings of other series, this study supports SRS as a standard practice in selected patients with larger numbers of BMs.

Hippocampal sparing in patients receiving radiosurgery for ≥25 brain metastases.

PURPOSE/OBJECTIVES: To report our dosimetric analysis of the hippocampi (HC) and the incidence of perihippocampal tumor location in patients with ≥25 brain metastases who received stereotactic radiosurgery (SRS) in single or multiple sessions. MATERIALS/METHODS: Analysis of our prospective registry identified 89 patients treated with SRS for ≥25 brain metastases. HC avoidance regions (HA-region) were created on treatment planning MRIs by 5 mm expansion of HC. Doses from each session were summed to calculate HC dose. The distribution of metastases relative to the HA-region and the HC was analyzed. RESULTS: Median number of tumors irradiated per patient was 33 (range 25-116) in a median of 3 (range1-12) sessions. Median bilateral HC Dmin (D100), D40, D50, Dmax, and Dmean (Gy) was 1.88, 3.94, 3.62, 16.6, and 3.97 for all patients, and 1.43, 2.99, 2.88, 5.64, and 3.07 for patients with tumors outside the HA-region. Multivariate linear regression showed that the median HC D40, D50, and Dmin were significantly correlated with the tumor number and tumor volume (p < 0.001). Of the total 3059 treated tumors, 83 (2.7%) were located in the HA-region in 57% evaluable patients; 38 tumors (1.2%) abutted or involved the HC itself. CONCLUSIONS: Hippocampal dose is higher in patients with tumors in the HA-region; however, even for patients with a high burden of intracranial disease and tumors located in the HA-regions, SRS affords hippocampal sparing. This is particularly relevant in light of our finding of eventual perihippocampal metastases in more than half of our patients.

National Resident Matching Program Performance Among US MD and DO Seniors in the Early Single Accreditation Graduate Medical Education Era.

INTRODUCTION: As of the 2020 National Resident Matching Program (NRMP), nearly all applicants are evaluated together for graduate medical education (GME) candidacy. We set out to characterize US MD and DO Senior residency match performance in the single-accreditation GME era. METHODS: A retrospective study was conducted in 2021 utilizing data collected from the 2018 and 2020 NRMP Charting Outcomes in the Match publications aggregated and subdivided into three groups based on competitiveness: low (LC), moderate (MC), and high (HC). Nonparametric analysis was performed using Chi square or Fisher exact tests if counts were less than five. Significance was determined at p < 0.05. RESULTS: A total of 46,853 candidates were included, with 36,194 (77.3%) US MD and 10,659 (22.7%) DO Seniors. Match rates for US DO Seniors were lower than US MD Seniors across all competitiveness strata (p < 0.0001). Research item production, national licensing examination scores, and mean number of contiguous programs ranked were lower for matched US DO Seniors compared to matched US MD Seniors, with significant differences depending on competitiveness group. CONCLUSIONS: With recent changes to GME and its application process, understanding how various groups compare will be increasingly important. US DO Seniors have lower first-rank match rates for all specialty competitiveness levels. This may be due to lower research output or nuanced specialty selection. This study could aid GME stakeholders to more effectively allocate resources and better prepare residency candidates.

Stereotactic Radiosurgery With Versus Without Embolization for Brain Arteriovenous Malformations.

BACKGROUND: Prior comparisons of brain arteriovenous malformations (AVMs) treated using stereotactic radiosurgery (SRS) with or without embolization were inherently flawed, due to differences in the pretreatment nidus volumes. OBJECTIVE: To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Patients were categorized into the embolization and SRS (E + SRS) or SRS alone (SRS-only) cohorts. The 2 cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was defined as AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiologic and symptomatic radiation-induced changes (RIC), and cyst formation. RESULTS: The matched cohorts each comprised 101 patients. Crude AVM obliteration rates were similar between the matched E + SRS vs SRS-only cohorts (48.5% vs 54.5%; odds ratio = 0.788, P = .399). Cumulative probabilities of obliteration at 3, 4, 5, and 6 yr were also similar between the E + SRS (33.0%, 46.4%, 56.2%, and 60.8%, respectively) and SRS-only (32.9%, 46.2%, 56.0%, and 60.6%, respectively) cohorts (subhazard ratio (SHR) = 1.005, P = .981). Cumulative probabilities of radiologic RIC at 3, 4, 5, and 6 yr were lower in the E + SRS (25.0%, 25.7%, 26.7%, and 26.7%, respectively) vs SRS-only (45.3%, 46.2%, 47.8%, and 47.8%, respectively) cohort (SHR = 0.478, P = .004). Symptomatic and asymptomatic embolization-related complication rates were 8.3% and 18.6%, respectively. Rates of post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation were similar between the matched cohorts. CONCLUSION: This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.

Embolization of Brain Arteriovenous Malformations With Versus Without Onyx Before Stereotactic Radiosurgery.

BACKGROUND: Embolization of brain arteriovenous malformations (AVMs) using ethylene-vinyl alcohol copolymer (Onyx) embolization may influence the treatment effects of stereotactic radiosurgery (SRS) differently than other embolysates. OBJECTIVE: To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Embolized AVMs treated with SRS were selected and categorized based on embolysate usage into Onyx embolization (OE + SRS) or non-Onyx embolization (NOE + SRS) cohorts. The 2 cohorts were matched in a 1:1 ratio using de novo AVM features for comparative analysis of outcomes. RESULTS: The matched cohorts each comprised 45 patients. Crude AVM obliteration rates were similar between the matched OE + SRS vs NOE + SRS cohorts (47% vs 51%; odds ratio [OR] = 0.837, P = .673). Cumulative probabilities of obliteration were also similar between the OE + SRS vs NOE + SRS cohorts (subhazard ratio = 0.992, P = .980). Rates of post-SRS hemorrhage, all-cause mortality, radiation-induced changes, cyst formation, and embolization-associated complications were similar between the matched cohorts. Sensitivity analysis for AVMs in the OE + SRS cohort embolized with Onyx alone revealed a higher rate of asymptomatic embolization-associated complications in this subgroup compared to the NOE + SRS cohort (36% vs 15%; OR = 3.297, P = .034), but the symptomatic complication rates were similar. CONCLUSION: Nidal embolization using Onyx does not appear to differentially impact the outcomes of AVM SRS compared with non-Onyx embolysates. The embolic agent selected for pre-SRS AVM embolization should reflect both the experience of the neurointerventionalist and target of endovascular intervention.

Black Bone Disease of the Skull.

We present an image of a patient's skull characterized by dark, irregular discoloration. This was discovered incidentally in a 66-year-old man who underwent craniotomy for resection of a glioblastoma. This image demonstrates cranial black bone disease. This is an abnormal bone pigmentation associated with long-term tetracycline use, as occurred in this patient.

Simultaneous Treatment of Petroclival Meningiomas and the Trigeminal Nerve with Gamma Knife Radiosurgery for Tumor-Related Trigeminal Neuralgia.

BACKGROUND: Some petroclival meningiomas cause trigeminal nerve compression, leading to disabling trigeminal neuralgia (TN). Tumor resection and nerve decompression can offer pain relief but might not be feasible in all patients. Simultaneous stereotactic radiosurgery (SRS) to the tumor and nerve is another option. SRS is an effective means of treating meningiomas and TN separately, but data on the efficacy and outcomes of their concomitant treatment are limited. CASE DESCRIPTION: We report a series of 4 patients who presented with TN secondary to a petroclival mass causing compression of the trigeminal nerve. All patients underwent SRS to both the petroclival mass and trigeminal nerve in a single session. The average margin tumor dose was 12.25 Gy (range, 12-12.5 Gy), and the average maximum trigeminal nerve dose was 80 Gy (range, 75-85 Gy). In all patients, before intervention, the Barrow Neurologic Institute (BNI) pain intensity score was grade IV or V. At last follow-up (average, 29.8 months), all patients were pain-free (BNI I or IIIA). Two patients experienced reduced facial sensation in 1 or all 3 distributions. No brainstem edema was seen. CONCLUSIONS: This series highlights the benefits and safety of simultaneous treatment of petroclival tumors and the trigeminal nerve in a single session for patients affected by tumor-related TN.

Intrareservoir Administration of Alteplase to Treat a Distal Ventriculoatrial Shunt Obstruction.

BACKGROUND: Ventriculoatrial shunts can be afflicted with distal malfunctions due to thrombus formation at the distal tip. Distal tip thrombus formation may occur more commonly in oncologic patients who are predisposed to hypercoagulability. CASE DESCRIPTION: A patient who had a ventriculoatrial shunt placed for leptomeningeal carcinomatosis presented with headaches and confusion and was found to have a partial distal shunt obstruction. Intrareservoir administration of alteplase resulted in resolution of her symptoms. Nuclear medicine shunt patency test demonstrated restoration of distal flow. CONCLUSIONS: Intrareservoir administration of alteplase can be a useful nonoperative treatment strategy for ventriculoatrial shunt malfunction. This strategy may be particularly useful in cases with higher perioperative risk, such as patients with advanced metastatic cancer.

DynaCT Enhancement of Subdural Membranes After Middle Meningeal Artery Embolization: Insights into Pathophysiology.

OBJECTIVE: Middle meningeal artery (MMA) embolization could be an effective method of inhibiting neovascularization of the subdural capsular membrane and preventing hematoma maintenance. We sought to better understand how the MMA might affect subdural hematoma physiology and how this process might be modified by embolization. METHODS: We performed a retrospective review of 27 patients with 29 subdural hematomas (SDHs) who had undergone MMA embolization from July 2018 to May 2019. Of the 27 patients, 8 had undergone postembolization DynaCT imaging studies and were included in the present study. RESULTS: The average patient age was 75 years. The baseline noncontrast-enhanced cranial computed tomography (CT) scans showed the presence of a hematoma membrane in all 8 patients. The postembolization DynaCT scans of all patients demonstrated enhancement of all 4 components (i.e., dura, capsular membrane, septations, and subdural hematoma fluid). All patients had a minimum of 60-day imaging and clinical follow-up data available. The average decrease in SDH volume at the last follow-up examination was 87% compared with that at baseline. A significant difference was found between the average baseline and average last follow-up SDH volume (P < 0.0001, paired t test) in all 8 patients. The average interval from the date of the procedure to the last follow-up scan was 89 days (range, 61-122 days). No patient experienced postembolization complications, subsequent SDH drainage, or mortality. CONCLUSIONS: Our data lend support to the theory of contiguous vascular networks between the MMA and SDH membranes. Targeting these leaky vascular networks might remove the source of hematoma accumulation. These data add to the pathophysiological understanding of the disease and suggests potential insights into the mechanism of action of MMA embolization.

Effect of Anatomic Segment Involvement on Stereotactic Radiosurgery for Facial Nerve Schwannomas: An International Multicenter Cohort Study.

BACKGROUND: Facial nerve schwannomas are rare, challenging tumors to manage due to their nerve of origin. Functional outcomes after stereotactic radiosurgery (SRS) are incompletely defined. OBJECTIVE: To analyze the effect of facial nerve segment involvement on functional outcome for these tumors. METHODS: Patients who underwent single-session SRS for facial nerve schwannomas with at least 3 mo follow-up at 11 participating centers were included. Preoperative and treatment variables were recorded. Outcome measures included radiological tumor response and neurological function. RESULTS: A total of 63 patients (34 females) were included in the present study. In total, 75% had preoperative facial weakness. Mean tumor volume and margin dose were 2.0 ± 2.4 cm3 and 12.2 ± 0.54 Gy, respectively. Mean radiological follow-up was 45.5 ± 38.9 mo. Progression-free survival at 2, 5, and 10 yr was 98.1%, 87.2%, and 87.2%, respectively. The cumulative proportion of patients with regressing tumors at 2, 5, and 10 yr was 43.1%, 63.6%, and 63.6%, respectively. The number of involved facial nerve segments significantly predicted tumor progression (P = .04). Facial nerve function was stable or improved in 57 patients (90%). Patients with involvement of the labyrinthine segment of the facial nerve were significantly more likely to have an improvement in facial nerve function after SRS (P = .03). Hearing worsened in at least 6% of patients. Otherwise, adverse radiation effects included facial twitching (3 patients), facial numbness (2 patients), and dizziness (2 patients). CONCLUSION: SRS for facial nerve schwannomas is effective and spares facial nerve function in most patients. Some patients may have functional improvement after treatment, particularly if the labyrinthine segment is involved.

Earlier radiosurgery leads to better pain relief and less medication usage for trigeminal neuralgia patients: an international multicenter study.

OBJECTIVE: Trigeminal neuralgia (TN) is a chronic pain condition that is difficult to control with conservative management. Furthermore, disabling medication-related side effects are common. This study examined how stereotactic radiosurgery (SRS) affects pain outcomes and medication dependence based on the latency period between diagnosis and radiosurgery. METHODS: The authors conducted a retrospective analysis of patients with type I TN at 12 Gamma Knife treatment centers. SRS was the primary surgical intervention in all patients. Patient demographics, disease characteristics, treatment plans, medication histories, and outcomes were reviewed. RESULTS: Overall, 404 patients were included. The mean patient age at SRS was 70 years, and 60% of the population was female. The most common indication for SRS was pain refractory to medications (81%). The median maximum radiation dose was 80 Gy (range 50-95 Gy), and the mean follow-up duration was 32 months. The mean number of medications between baseline (pre-SRS) and the last follow-up decreased from 1.98 to 0.90 (p < 0.0001), respectively, and this significant reduction was observed across all medication categories. Patients who received SRS within 4 years of their initial diagnosis achieved significantly faster pain relief than those who underwent treatment after 4 years (median 21 vs 30 days, p = 0.041). The 90-day pain relief rate for those who received SRS ≤ 4 years after their diagnosis was 83.8% compared with 73.7% in patients who received SRS > 4 years after their diagnosis. The maximum radiation dose was the strongest predictor of a durable pain response (OR 1.091, p = 0.003). Early intervention (OR 1.785, p = 0.007) and higher maximum radiation dose (OR 1.150, p < 0.0001) were also significant predictors of being pain free (a Barrow Neurological Institute pain intensity score of I-IIIA) at the last follow-up visit. New sensory symptoms of any kind were seen in 98 patients (24.3%) after SRS. Higher maximum radiation dose trended toward predicting new sensory deficits but was nonsignificant (p = 0.075). CONCLUSIONS: TN patients managed with SRS within 4 years of diagnosis experienced a shorter interval to pain relief with low risk. SRS also yielded significant decreases in adjunct medication utilization. Radiosurgery should be considered earlier in the course of treatment for TN.

Stereotactic radiosurgery with versus without prior Onyx embolization for brain arteriovenous malformations.

OBJECTIVE: Investigations of the combined effects of neoadjuvant Onyx embolization and stereotactic radiosurgery (SRS) on brain arteriovenous malformations (AVMs) have not accounted for initial angioarchitectural features prior to neuroendovascular intervention. The aim of this retrospective, multicenter matched cohort study is to compare the outcomes of SRS with versus without upfront Onyx embolization for AVMs using de novo characteristics of the preembolized nidus. METHODS: The International Radiosurgery Research Foundation AVM databases from 1987 to 2018 were retrospectively reviewed. Patients were categorized based on AVM treatment approach into Onyx embolization (OE) and SRS (OE+SRS) or SRS alone (SRS-only) cohorts and then propensity score matched in a 1:1 ratio. The primary outcome was AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiological and symptomatic radiation-induced changes (RICs), and cyst formation. Comparisons were analyzed using crude rates and cumulative probabilities adjusted for competing risk of death. RESULTS: The matched OE+SRS and SRS-only cohorts each comprised 53 patients. Crude rates (37.7% vs 47.2% for the OE+SRS vs SRS-only cohorts, respectively; OR 0.679, p = 0.327) and cumulative probabilities at 3, 4, 5, and 6 years (33.7%, 44.1%, 57.5%, and 65.7% for the OE+SRS cohort vs 34.8%, 45.5%, 59.0%, and 67.1% for the SRS-only cohort, respectively; subhazard ratio 0.961, p = 0.896) of AVM obliteration were similar between the matched cohorts. The secondary outcomes of the matched cohorts were also similar. Asymptomatic and symptomatic embolization-related complication rates in the matched OE+SRS cohort were 18.9% and 9.4%, respectively. CONCLUSIONS: Pre-SRS AVM embolization with Onyx does not appear to negatively influence outcomes after SRS. These analyses, based on de novo nidal characteristics, thereby refute previous studies that found detrimental effects of Onyx embolization on SRS-induced AVM obliteration. However, given the risks incurred by nidal embolization using Onyx, this neoadjuvant intervention should be used judiciously in multimodal treatment strategies involving SRS for appropriately selected large-volume or angioarchitecturally high-risk AVMs.