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OBJECTIVE Stereotactic radiosurgery (SRS) is an effective treatment for brain metastases (BMs) in patients with non–small cell lung cancer (NSCLC). However, factors associated with the development of post-SRS leptomeningeal metastasis (LM) remain unclear. The authors analyzed the incidence and risk factors of LM development in patients with NSCLC and BMs after SRS and examined the survival outcomes and prognostic factors after LM development. METHODS This retrospective study included patients with NSCLC treated with SRS for MRI-diagnosed BM from 2002 to 2021. The authors recorded various clinical and demographic data, including age, sex, tumor histology, molecular profile of tumors, extracranial disease status, previous craniotomy, Karnofsky Performance Status, systemic treatments, tumor volume, and number of BMs. The management and survival outcomes after LM diagnosis were also recorded. RESULTS LM developed in 13.7% of patients with NSCLC and BMs after SRS treatment. Large initial tumor volume and more than 5 BM lesions, but not EGFR mutation status and post-SRS treatment, were associated with LM development after SRS. Multivariate analysis revealed that chemotherapy and targeted therapy after LM were associated with better survival in patients with LM after SRS. CONCLUSIONS This study is the first to evaluate the risk factors for LM in a relatively large cohort of patients with NSCLC after SRS. In patients with BMs harboring risk factors for subsequent LM, such as initial tumor volume and number of metastatic lesions, aggressive therapies with high CNS penetrating ability should be considered.

To explore the impact of outflow patency on radiosurgical outcomes of lateral sinus dural arteriovenous fistulas (DAVFs).We retrospectively examined 83 lateral sinus DAVFs treated with Gamma Knife radiosurgery (GKRS) between 1995 and 2020. Two neuroradiologists blinded to the therapeutic outcomes served as imaging evaluators on pre-GKRS digital subtraction angiography and magnetic resonance images. The sinovenous outflow of lateral sinus DAVF was scored using combined conduit score (CCS), ranging from 0 (total occlusion) to 8 (full patency). The patients' follow-up magnetic resonance and digital subtraction angiography images were used to validate the radiosurgical outcomes (obliteration or non-obliteration) of lateral sinus DAVF. Cox regression and Kaplan-Meier analyses were performed to determine the correlations between the variables and outcomes.Among the 83 cases, 60 (72%) lateral sinus DAVFs achieved obliteration after a GKRS at a median latency period of 24.5 months. After adjustment for aggressive presentation, cortical venous reflux, straight sinus reflux, and optic nerve sheath enlargement, a CCS of6 was independently associated with lateral sinus DAVF obliteration (hazard ratio: 2.335, P = 0.007). The estimated 36-month probabilities of obliteration were 80% versus 53.6% for lateral sinus DAVFs with a CCS of6 versus ≤6.Lateral sinus DAVFs with a CCS of6, indicating a nearly patent sinovenous outflow, were more likely to be obliterated after GKRS. Sinovenous outflow patency is a factor associated with therapeutic outcomes in radiosurgery for lateral sinus DAVFs.

Knowledge about the natural course of brain arteriovenous malformations (AVMs) have increased during the past 20 years, as has the number of AVMs treated, especially larger ones. It is thus timely to again analyze the risk for hemorrhage after Gamma Knife Surgery (GKS).To confirm or contradict conclusions drawn 20 years ago regarding factors that affect the risk for post-GKS hemorrhage.The outcome after GKS was studied in 5037 AVM patients followed for up to 2 years. The relation between post-treatment hemorrhage rate and a number of patient, AVM, and treatment parameters was analyzed. The results were also compared with the results from our earlier study.The annual post-treatment hemorrhage rate was 2.4% the first 2 years after GKS. Large size, low treatment dose, and old age were independent risk factors for AVM hemorrhage. After having compensated for the factors above, peripheral AVM location and female sex, at least during their child bearing ages, were factors associated with a lower post-GKS hemorrhage rate.Large AVMs (5 cm 3 ) treated with low doses (≤16 Gy) had higher and small AVMs treated with high doses a lower risk for hemorrhage as compared with untreated AVMs. This was detectable within the first 6 months after GKS. No difference in hemorrhage rate could be detected for the other AVMs. Based on our findings, it is advisable to prescribe16 Gy to larger AVMs, assuming that the risk for radiation-induced complications can be kept at an acceptable level.

OBJECTIVE The goal of this study was to assess the safety and efficacy of single-session Gamma Knife radiosurgery (GKRS) for orbital cavernous hemangiomas (OCHs). METHODS Patients who presented with an OCH between September 1999 and May 2022 and were treated with single-session GKRS were included in this single-center cohort study. RESULTS There were 23 patients (7 males and 16 females) in this study. The median margin dose was 12 Gy (range 11–13 Gy). The median clinical and radiological follow-ups were 45 months (range 5–190 months) and 45 months (range 6–190 months), respectively. Nine (69.2%) of 13 patients with visual acuity impairment had improvement in best corrected visual acuity. Of the 8 patients with visual field defects, 5 patients (62.5%) had complete resolution. Tumor regression was observed in 22 patients (95.7%). The mean relative reduction in tumor volume was 82.6% ± 23.7%. The relative reductions in tumor volume were 33%, 49%, 72%, 84%, and 89% at 6, 12, 24, 36, and 48 months, respectively. Adverse effects of radiation were not observed. CONCLUSIONS GKRS appears to be safe and efficacious for treating OCHs over long-term follow-up. The treatment is associated with a high rate of regression in OCHs and remarkable improvement in both visual acuity and visual field deficits.

OBJECTIVE Whether combined radiation and tyrosine kinase inhibitor (TKI) therapy in non–small cell lung cancer (NSCLC) patients with brain metastases (BMs) and epidermal growth factor receptor (EGFR) mutations confers additional benefits over TKI therapy alone remains a matter of debate. The goal of this study was to compare outcomes between combined TKI therapy with stereotactic radiosurgery (SRS) versus TKI therapy alone in NSCLC patients with BMs and EGFR mutations. METHODS Consecutive cases of NSCLC patients with EGFR mutations and BMs treated with TKIs were selected for inclusion in this study. Patients were categorized into two groups based on SRS: TKI therapy alone (group I) and combined SRS and TKI therapy (group II). Patients who had SRS or TKI as salvage therapy and those with prior radiation treatment for BMs were excluded. Tumor control (< 10% increase in tumor volume) and overall survival (OS) rates were compared using Kaplan-Meier analyses. Independent predictors of tumor control and OS were identified using multivariable Cox regression analyses. RESULTS The study cohort comprised 280 patients (n = 90 in group I and n = 190 in group II). Cumulative tumor control rates were higher in group II than in group I (79.8% vs 31.2% at 36 months, p < 0.0001). Cumulative OS rates were comparable between groups I and II (43.8% vs 59.4% at 36 months, p = 0.3203). Independent predictors of tumor control were older age (p < 0.01, HR 1.03), fewer BMs (p < 0.01, HR 1.09), lack of extracranial metastasis (p < 0.02, HR 0.70), and combined SRS and TKI therapy (p < 0.01, HR 0.25). Independent predictors of OS were fewer BMs (p < 0.01, HR 1.04) and a higher Karnofsky Performance Status score (p < 0.01, HR 0.97). CONCLUSIONS Although the OS rate did not differ between TKI therapy with and without SRS, the addition of SRS to TKI therapy resulted in improvement of intracranial tumor control. The lack of effect on survival rate with the addition of SRS may be attributable to extracranial disease progression. The addition of SRS to TKI therapy is recommended for intracranial disease control in NSCLC patients with BMs and EGFR mutations. Potential benefits may include prevention of neurological deficits and seizures. Future prospective studies may help clarify the clinical outcome benefits of SRS in these patients.

Purpose This study was to determine whether combining blood-brain-barrier-penetrant tyrosine kinase inhibitor (TKI), osimertinib, with intracranial radiotherapy (TKI + RT) would confer benefits exceeding those of osimertinib alone (TKI-alone) in terms of treatment outcomes among non-small cell lung cancer (NSCLC) patients with brain metastases and epidermal growth factor receptor (EGFR) mutation. Methods This single-center retrospective study focused on gamma-knife radiosurgery (GKRS) and whole brain radiotherapy (WBRT). Treatment outcomes included intracranial local tumor control, intracranial distant tumor control and overall survival (OS) rates. Results This study included 567 brain metastases in 69 patients: TKI-alone (n = 38) and TKI + RT (n = 31) including GKRS (n = 25) and WBRT (n = 6). Intracranial local tumor control at 36 months was significantly higher in the TKI + RT than in the TKI-alone (77% vs. 23%; p

To study the prognostic features of Creutzfeldt-Jakob disease (CJD) and shed light on its future therapy.Retrospective cohort study of a longitudinal national cohort of the Taiwan Centers for Disease Control.All patients with suspected CJD are reported to the CJD surveillance unit of the Taiwan Centers for Disease Control. An expert committee discussed the reported cases and designated a consensus-based diagnosis. From 1996 to 2020, a total of 809 cases were referred to the CJD surveillance unit for confirmation; of these, 441 cases (women, n = 230) were determined to be sporadic CJD.We investigated the clinical manifestations and laboratory findings for 400 patients diagnosed with definite or probable sporadic CJD. We used Kaplan-Meier analyses and Cox proportional hazards model to identify prognostic factors.The mean age of onset was 67 ± 9.9 years. The mean survival duration was 13.3 ± 14.2 (median 10) months. The leading clinical symptoms were myoclonus (73%) and akinetic mutism (54%). For PRNP polymorphism, 99% of patients (195/197) showed a methionine homozygous genotype at codon 129 (M129M). The sensitivity of periodic sharp wave complexes (PSWCs) on electroencephalograms (EEGs) was 59.7%. The sensitivity of cerebrospinal fluid 14-3-3 protein and total tau protein (1200 pg/mL) were 69.7% and 75.6%, respectively. Younger patients lived longer than those aged ≥65 years [hazard ratio (HR) 0.466, P.001]. Women had a better survival probability in the first 3 years than their male counterparts (HR 0.712, P = .005). PSWCs had a persistent negative effect on survival (HR 0.788, P.05). Although uncommon, epileptic seizures were the only clinical prognostic factor for survival time (HR 0.768, P.05). PSWCs can be used as an EEG biomarker for prognosis. Epileptic seizures, though not common, are the only clinical prognostic factor for a short survival.We found that a lower age of onset and female gender favor the survival of patients with sCJD. PSWCs are EEG biomarkers unfavorable for survival, and so are epileptic seizures.

Seizure is the most common clinical presentation in patients with nonhemorrhagic brain arteriovenous malformations (BAVMs) and it influences their quality of life. Angioarchitectural analysis of the seizure risk for BAVMs is subjective and does not consider hemodynamics. This study aimed to investigate the angioarchitectural and hemodynamic factors that may be associated with seizure in patients with BAVMs.From 2011 to 2019, 104 patients with supratentorial BAVMs without previous hemorrhage or treatment were included and grouped according to the initial presentation of seizure. Their angiograms and MRI results were analyzed for morphological characteristics and quantitative digital subtraction angiography (QDSA) parameters. Modified cerebral circulation time (mCCT) was defined as the difference between the bolus arrival time of the ipsilateral cavernous internal carotid artery and the parietal vein on lateral DSA. Logistic regression analysis was performed to estimate the odds ratio (OR) for BAVMs presenting with seizure.The seizure group had shorter mCCT (1.98 s vs. 2.44 s, p = 0.005) and more BAVMs with temporal location (45% vs. 30.8%, p = 0.013), neoangiogenesis (55% vs. 33%, p = 0.03), and long draining veins (95% vs. 72%, p = 0.004) than did the nonseizure group. Shorter mCCT (OR: 3.4, p = 0.02), temporal location (OR: 13.4, p0.001), and neoangiogenesis (OR: 4.7, p = 0.013) were independently associated with higher risks of seizure, after adjustments for age, gender, BAVM volume, and long draining vein.Shorter mCCT, temporal location, and neoangiogenesis were associated with epileptic BAVMs. QDSA can objectively evaluate hemodynamic changes in epileptic BAVMs.• Quantitative digital subtraction angiography may be used to evaluate the hemodynamic differences between brain arteriovenous malformations presenting with and without seizure. • BAVMs with temporal location, neoangiogenesis, and shortened cerebral circulation time were more likely to present with seizure.

BACKGROUND This study aimed to compare the prediction performance of two-dimensional (2D) and three-dimensional (3D) semantic segmentation models for intracranial metastatic tumors with a volume ≥ 0.3 mL. METHODS We used postcontrast T1 whole-brain magnetic resonance (MR), which was collected from Taipei Veterans General Hospital (TVGH). Also, the study was approved by the institutional review board (IRB) of TVGH. The 2D image segmentation model does not fully use the spatial information between neighboring slices, whereas the 3D segmentation model does. We treated the U-Net as the basic model for 2D and 3D architectures. RESULTS For the prediction of intracranial metastatic tumors, the area under the curve (AUC) of the 3D model was 87.6% and that of the 2D model was 81.5%. CONCLUSION Building a semantic segmentation model based on 3D deep convolutional neural networks might be crucial to achieve a high detection rate in clinical applications for intracranial metastatic tumors.

In this study we report our 30-year experience in stereotactic radiosurgery (SRS) treatment of lung squamous cell carcinoma (LUSC) brain metastases (BMs). It will serve to provide detailed longitudinal outcomes and predictors of efficacy in treating LUSC-BMs with SRS.We retrospectively reviewed 51 patients and 109 tumors treated with SRS at our center between 1993 and 2022. Patient demographics, PDL1 genotype, immunotherapy use and mortality cause were recorded. Radiological and clinical outcomes were followed at 1-3-month intervals post-SRS. Cox-regression analysis and Kaplan-Meier survival curves were performed in statistical analysis.We included 37 male and 14 female patients (median age 62.7 years at BM diagnosis). Median overall survival (OS) time was 6.9 months, 6-month OS rate was 62.1%, and Karnofsky performance scale (KPS) was the only independent predictor. Median time for local control maintenance was 7.6 months, 6-month local control rate was 69.1%, with TKI as the only independent predictor. Median time to distant failure was 5.13 months, 6-month distant failure rate was 51.1%, and factors with significant impact included gender (p = 0.002), presence of extracranial metastases (p 0.001), use of immunotherapy(p 0.001), PDL1 genotype (p = 0.034), and total intracranial metastases number (p = 0.008). However, no definitive benefits of immunotherapy were identified in patients with higher PDL1 mutational tumors.In this study we defined the natural history of disease progression and outcomes in SRS-treated LUSC-BM patients. We also identified predictors of OS and tumor control among these patients. The findings of this study will serve as a guide when counseling these patients for SRS.

BackgroundWhole brain radiation therapy (WBRT) for brain metastases (BMs) is a common cause of radiation-induced leukoencephalopathy; however the safety of alternative stereotactic radiosurgery (SRS) remains unclear. This study examined the incidence of leukoencephalopathy in patients treated with SRS alone versus WBRT plus SRS for BMs with a focus on the relationship between prognostic factors and leukoencephalopathy.MethodsAnalysis was performed between 2002 and 2021. The total enrollment was 993 patients with the distribution: WBRT plus SRS (n=291) and SRS only (n=702). Leukoencephalopathy was graded from 0 to 3 for changes in white matter indicated by the MRI after WBRT or SRS. Patient characteristics and SRS dosimetric parameters were reviewed to identify factors that contributed to the incidence of leukoencephalopathy or overall survival.ResultsThe incidence of leukoencephalopathy was consistently higher in WBRT plus SRS group than in SRS alone group (p＜0.001). Leukoencephalopathy was also associated with a larger total tumor volume (≧28cm3; p=0.028) and age (＞77 years; p=0.025). Nonetheless, the SRS integral dose to skull in the subgroup of WBRT plus SRS treatment was not demonstrated significance in development of leukoencephalopathy (p=0.986 for integral dose 1-2J, p=0.776 for integral dose＞2J).ConclusionsThis study revealed that SRS is safe for oligo-BMs in terms of leukoencephalopathy development. Patient age and total tumor volume were identified as important factors in assessing the development of leukoencephalopathy. The additional of SRS (even at an integral dose＞2J) did not increase the incidence of leukoencephalopathy.

Background: We proposed an algorithm to automate the components within the identification of components within the nidus of cerebral arteriovenous malformations (AVMs) which may be used to analyze the relationship between its diffuseness and treatment outcomes following stereotactic radiosurgery (SRS). Objectives: to determine the impact of the diffuseness of the AVM nidus on SRS outcomes. Methods: This study conducted regular follow-ups of 209 patients with unruptured AVMs who underwent SRS. The diffuseness of the AVM nidus was estimated by quantifying the proportions of vascular nidal component, brain parenchyma, and cerebrospinal fluid in T2-weighted MRIs. We used Cox regression analysis to characterize the association between nidal diffuseness and treatment outcomes in terms of obliteration rate and radiation-induced change (RICs) rate following SRS. Results: The median AVM volume was 20.7 cm3. The median duration of imaging follow-up was 51 months after SRS. The overall AVM obliteration rate was 68.4%. RICs were identified in 156 of the 209 patients (74.6%). The median proportions of the nidus of AVM and brain parenchyma components within the prescription isodose range were 30.2 and 52.2%, respectively. Cox regression multivariate analysis revealed that the only factor associated with AVM obliteration rate after SRS was AVM volume. However, a larger AVM volume (>20 mL) and a larger proportion of brain parenchyma (>50%) within the prescription isodose range were both correlated with a higher RIC rate following SRS. Conclusions: The diffuseness of the nidus indeed appears to affect the RIC rate following SRS in patients with unruptured AVMs.

Objective: Tyrosine kinase inhibitors (TKIs) is the first-line treatment for EGFR-positive non-small cell lung cancer (NSCLC); however, its applicability to patients with wild-type NSCLC remains an issue of contention. This study compared the effects of gamma knife radiosurgery (GKRS) alone versus combining GKRS and TKIs in treating two genetic forms of NSCLC.Methods: This retrospective study examined 479 NSCLC patients with 1982 brain metastases who underwent GKRS and for whom imaging follow-up data or death records were available. All our patients were consecutive. All gene mutations were confirmed by lung biopsy. The three main endpoints in this study were overall survival (OS), local intracranial tumor control (LC) , and distal intracranial tumor control (DC).Results: There were 296 NSCLC patients with EGFR positive: TKI treatment (n= 262) and without TKI treatment (n= 34). GKRS + TKIs was more effective than GKRS alone in terms of OS (HR: 0.53, p= 0.085) and DC (HR: 0.51, pConclusions: Combining GKRS with TKIs proved effective in EGFR positive NSCLC patients; however, we do not observe the similar results when combining GKRS with TKIs for patients with wild-type NSCLC

To investigate sinovenous outflow restriction (SOR) in lateral sinus dural arteriovenous fistulas (LSDAVFs) after Gamma Knife radiosurgery (GKRS) and its association with complete obliteration.We retrospectively (1995-2019) enrolled 39 patients with LSDAVFs who had undergone GKRS alone and evaluated their angiography and magnetic resonance imaging (MRI) before and after GKRS. The LS conduits ipsilateral and contralateral to the DAVFs were scored using a 5-point scoring system, with scores ranging from 0 (total occlusion) to 4 (fully patent). SOR was defined by a conduit score 2. Demographics, imaging features, and outcomes were compared between patients with and without ipsilateral SOR after GKRS. Logistic regression analysis was performed to estimate the odds ratio (OR) for obliteration with the imaging findings.After a median angiographic follow-up of 28 months for the 39 patients, the ipsilateral LS became more restrictive (median conduit score before and after GKRS: 2 vs. 1, p = .011). Twenty-one patients with ipsilateral SOR after GKRS had a significantly lower obliteration rate (52.4% vs. 94.4%, p = .005) than those without SOR. Follow-up SOR was independently associated with a lower obliteration rate (OR 0.05, p = .017) after adjustment for age, cortical venous reflux, and absent sinus flow void on MRI.This study demonstrates a restrictive change of outflow in LSDAVFs after GKRS and a lower obliteration rate in patients with SOR. Follow-up imaging for SOR may help predict outcomes of these patients.

To evaluate the clinical and imaging presentation, management, and outcome of iatrogenic retroperitoneal hematomas (IRPHs) during a series of neurointerventional procedures (NIPs).Six IRPH patients with complications, including five renal subcapsular hematomas (RSH) and one retroperitoneal hemorrhage, were observed among 2290 NIPs performed at our hospital from 2000 through 2020. The medical records, neurointerventional techniques, imaging data, and management of these six IRPH patients were retrospectively reviewed. All six patients received preprocedural dual antiplatelet medication and intraprocedural heparinization.All patients underwent right femoral access. The guidewires were not handled under full course fluoroscopy monitoring. The most common symptom of IRPH was periprocedural flank/abdominal pain (6/6, 100%), including five on the left side (83.3%). Hypotension or shock was observed in three patients (50%). Two patients (33%) were diagnosed intraoperatively by sonogram and received on-site treatment, whereas the other four were diagnosed by postprocedural abdominal computed tomography. Active extravasation from a renal artery was diagnosed by angiogram in the five patients with RSH and was successfully treated with embolization. Multiple bleeders in the branches of the renal artery were noted in three RSH patients (60%). The patient with retroperitoneal hematoma was treated conservatively.Unexplained periprocedural or postprocedural abdominal/flank pain, especially contralateral to the femoral access side of the NIPs, should raise the possibility of IRPH. To prevent IRPH, the authors suggest using full visual fluoroscopic monitoring for guidewire navigation during femoral catheterization of NIPs.

Introduction Epidemiologic studies of Creutzfeldt-Jakob disease (CJD) have been undertaken worldwide since the new variant CJD outbreak in 1996 in the United Kingdom. A nationwide report system, the Creutzfeldt-Jakob Disease Surveillance Unit (CJDSU), directed by the Centers for Disease Control of Taiwan, was established in 1997 to identify human prion diseases. Methods From 1998 to 2017, 647 cases were referred to the committee for confirmation. The report to CJDSU included a structured questionnaire recording the clinical, demographic data, and potential iatrogenic exposure, and the results of the clinical and laboratory examination, including tests of blood and cerebrospinal fluid, electroencephalography, and brain magnetic resonance imaging. Results In total, 356 cases (women, n=178) were ascertained to be human prion diseases, and 97.4% (n=347) were sporadic CJD, including three definite, 314 probable, and 30 possible cases; one probable variant CJD and 8 cases of the genetic form human prion diseases. The age- and gender-specific average annual incidence were also significantly higher in the second decade (0.95/1,000,000) than in the first decade (0.63/1,000,000), with an incidence rate ratio of 1.51. The incidences increased with increasing age, reaching a peak at the age of 70-79 years. The 10-year survival curve for sCJD patients showed that the 1-, 5-, and 10-year cumulative survival rate were 52%, 5%, and 1%, respectively. PRNP polymorphisms in 170 patients showed that 98.8% were M129M and 97.6% E219E. Discussion The significant increase in incidence after 2008 suggests the increase in the awareness of this rare disease among physicians. The longer disease duration in patients with sCJD in Taiwan than in other countries indicates that the comprehensive support of the health care system, as well as the end-of-life care culture in Taiwan, may prolong survival time in patients with such a progressive and fatal disease.

BACKGROUND Stent patency after carotid angioplasty and stenting (CAS) correlates not only with stroke prevention but also with improvements in cognition and quality of life by positively influencing cerebral perfusion. The long-term outcomes of CAS after more than 5 years have still not been well described. This retrospective study was designed to evaluate the stent patency and significant restenosis (SR) after CAS with more than 5 years of follow-up. METHODS Between 2006 and 2012, 118 patients with carotid stenosis who underwent 131 CAS procedures with regular annual imaging follow-up for more than 5 years were enrolled. We evaluated their demographic characteristics and the risk factors related to stent restenosis. Patients with SR (restenosis ≥ 50%) were compared with those with no significant restenosis (NSR, patency or restenosis < 50%) to identify the restenosis predictors and restenosis-free survival. RESULTS Of the 131 CAS procedures, 16.0% (21/131) had SR. A history of head and neck radiotherapy (HNRT) was a predictor for SR (HR, 6.352; 95% CI, 2.504-16.112; p < 0.001) and was associated with shorter restenosis-free survival (log-rank test p value < 0.001, median time of restenosis-free survival was 38 months). Left-sided stenting was an associated factor for SR (HR, 3.007; 95% CI, 1.068-8.467; p = 0.037) with a trend of less restenosis-free survival (log-rank test p value 0.067). CONCLUSION Both HNRT and left-sided carotid stenosis were predictors of SR after CAS in more than 5 years of long-term follow-up. Restenosis-free survival was significantly shorter in patients with prior HNRT than in patients without previous irradiation treatment. We suggest close follow-up and aggressive medical treatment for patients with prior HNRT and left-sided carotid stenosis undergoing CAS.

Stereotactic radiosurgery (SRS) is a potential re-irradiation treatment for recurrent intracranial ependymoma after prior radiation therapy. The purpose of this study was to examine the efficacy and safety of repeated SRS in the treatment of recurrent intracranial ependymomas. This is a retrospective study of consecutive patients with residual or recurrent intracranial ependymomas who were treated with SRS between 1993 and 2018. Tumor progression was defined as a ≥ 10% increase in tumor volume. Tumor regression was defined as a ≥ 10% reduction in tumor volume. A tumor that remained within 10% of its original volume was defined as stable. Tumor control comprised tumor regression and stability. Time-dependent analyses were performed using two treatment failure endpoint definitions: (1) evidence of local tumor progression or distant metastasis (single SRS analysis), and (2) lack of tumor response to SRS (repeated SRS analysis). These analyses were adjusted for the competing risk of death. The study comprised 37 patients (65 intracranial ependymomas) who underwent multiple SRS sessions (range: 1–7). Median age was 10.2 years (range: 0.8–53.8 years), and median tumor volume was 1.5 mL (range: 0.01–22.5 mL). The median radiation dose was 13.3 Gy (range: 7.9–22.0 Gy) at a median isodose line of 57% (range: 50–90%). Overall tumor control rates in the single SRS analysis adjusting for the competing risk of death were 53.6%, 30.5%, and 23.6% at 1, 3, and 5 years, respectively. Overall tumor control rates in the repeated SRS analysis adjusting for the competing risk of death were 70.6%, 50.4%, and 43.1% at 1, 3, and 5 years, respectively. Prior gross total resection was the only independent predictor of overall tumor control after SRS (aHR = 25.62 (1.55–422.1), p = 0.02). Repeated GKRS appeared to be an effective treatment strategy for recurrent or residual intracranial ependymomas, with acceptable complication rates.

OBJECTIVEAssessments of hemorrhage risk based on angioarchitecture have yielded inconsistent results, and quantitative hemodynamic studies have been limited to small numbers of patients. The authors examined whether cerebral hemodynamic analysis using quantitative digital subtraction angiography (QDSA) can outperform conventional DSA angioarchitecture analysis in evaluating the risk of hemorrhage associated with supratentorial arteriovenous malformations (AVMs).METHODSA cross-sectional study was performed by retrospectively reviewing adult supratentorial AVM patients who had undergone both DSA and MRI studies between 2011 and 2017. Angioarchitecture characteristics, DSA parameters, age, sex, and nidus volume were analyzed using univariate and multivariate logistic regression, and QDSA software analysis was performed on DSA images. Based on the QDSA analysis, a stasis index, defined as the inflow gradient divided by the absolute value of the outflow gradient, was determined. The receiver operating characteristic (ROC) curve was used to compare diagnostic performances of conventional DSA angioarchitecture analysis and analysis using hemodynamic parameters based on QDSA.RESULTSA total of 119 supratentorial AVM patients were included. After adjustment for age at diagnosis, sex, and nidus volume, the exclusive deep venous drainage (p < 0.01), observed through conventional angioarchitecture examination using DSA, and the stasis index of the most dominant drainage vein (p = 0.02), measured with QDSA hemodynamic analysis, were independent risk factors for hemorrhage. The areas under the ROC curves for the conventional DSA method (0.75) and QDSA hemodynamics analysis (0.73) were similar. A venous stasis index greater than 2.18 discriminated the hemorrhage group with a sensitivity of 52.6% and a specificity of 81.5%.CONCLUSIONSIn QDSA, a higher stasis index of the most dominant drainage vein is an objective warning sign associated with supratentorial AVM rupture. Risk assessments of AVMs using QDSA and conventional DSA angioarchitecture were equivalent. Because QDSA is a complementary noninvasive approach without extra radiation or contrast media, comprehensive hemorrhagic risk assessment of cerebral AVMs should include both DSA angioarchitecture and QDSA analyses.

Clinical features are the primary measures used for risk assessment of cerebrovascular diseases. However, clinical features, especially angioarchitecture, in digital subtraction angiography require further interpretation by specialized radiologists. This approach for risk assessment requires multivariable analysis and is, therefore, challenging when completed manually. In this study, we employed three machine learning models, namely the random forest, naïve Bayes classifier, and support vector machine, for the detection of hemorrhagic brain arteriovenous malformations using digital subtraction angiography. Quantitative measurements from digital subtraction angiography were used as features, and the chi-squared test, minimum redundancy maximum relevance, ReliefF, and two-sample $t$ tests were used for feature selection. Bayesian optimization was conducted to optimize the hyperparameters of the three models. The random forest model outperformed the other two models. As a human control, three radiologists diagnosed an independent testing data set. The random forest model had a computation time of less than a second for the whole data set for classification. Accuracy and the area under the receiver operating characteristic curve were 92.7% and 0.98 for the training data set and 85.7% and 0.97 for the independent testing data set, respectively. Compared with the mean diagnosis time of approximately half a minute per patient and the highest accuracy of 76.2% for the three radiologists, the random forest model was faster and more accurate for our data set. These results suggest that the machine learning model based on hemodynamic features from quantitative digital subtraction angiography is a promising tool for detecting hemorrhagic brain arteriovenous malformations.

OBJECTIVEGamma Knife surgery (GKS) obliterates 65%–87% of cavernous sinus dural arteriovenous fistulas (CSDAVFs). However, the hemodynamic effect on GKS outcomes is relatively unknown. The authors thus used the classification scheme developed by Suh et al. to explore this effect.METHODSThe authors retrospectively (1993–2016) included 123 patients with CSDAVFs who received GKS alone at the institute and classified them as proliferative type (PT; n = 23), restrictive type (RT; n = 61), or late restrictive type (LRT; n = 39) after analyzing their pre-GKS angiography images. Treatment parameters, the presence of numerous arterial feeders, and venous drainage numbers were compared across the CSDAVF types. Patients’ follow-up MR images were evaluated for the presence of complete obliteration. A Kaplan-Meier analysis was conducted to determine the correlation between CSDAVF types and outcomes.RESULTSThe 36-month probability of complete obliteration was 74.3% for all patients, with no significant differences across types (p = 0.56). PT had the largest radiation volume (6.5 cm3, p < 0.001), the most isocenters (5, p = 0.015) and venous drainage routes (3, p < 0.001), and the lowest peripheral dose (16.6 Gy, p = 0.011) and isodose level coverage (64.3%, p = 0.006). CSDAVFs presenting with ocular patterns were less likely to be completely obliterated (hazard ratio 0.531, p = 0.009). After adjustment for age, CSDAVFs with more venous drainage routes were less likely to be completely obliterated (hazard ratio 0.784, p = 0.039).CONCLUSIONSGKS is an equally effective treatment option for all 3 CSDAVF types. Furthermore, the number of venous drainage routes may help in predicting treatment outcomes and making therapeutic decisions.

GKRS is an effective treatment for smaller intracranial tumors with a high control rate and low risk of complications. Target delineation in medical MR images is essential in the planning of GKRS and follow-up. A deep learning-based algorithm can effectively segment the targets from medical images and has been widely explored. However, state-of-the-art deep learning-based target delineation uses fixed sizes, and the isotropic voxel size may not be suitable for stereotactic MR images which use different anisotropic voxel sizes and numbers of slices according to the lesion size and location for clinical GKRS planning. This study developed an automatic deep learning-based segmentation scheme for stereotactic MR images.We retrospectively collected stereotactic MR images from 506 patients with VS, 1,069 patients with meningioma and 574 patients with BM who had been treated using GKRS; the lesion contours and individual T1W+C and T2W MR images were extracted from the GammaPlan system. The three-dimensional patching-based training strategy and dual-pathway architecture were used to manage inconsistent FOVs and anisotropic voxel size. Furthermore, we used two-parametric MR image as training input to segment the regions with different image characteristics (e.g., cystic lesions) effectively.Our results for VS and BM demonstrated that the model trained using two-parametric MR images significantly outperformed the model trained using single-parametric images with median Dice coefficients (0.91, 0.05 versus 0.90, 0.06, and 0.82, 0.23 versus 0.78, 0.34, respectively), whereas predicted delineations in meningiomas using the dual-pathway model were dominated by single-parametric images (median Dice coefficients 0.83, 0.17 versus 0.84, 0.22). Finally, we combined three data sets to train the models, achieving the comparable or even higher testing median Dice (VS: 0.91, 0.07; meningioma: 0.83, 0.22; BM: 0.84, 0.23) in three diseases while using two-parametric as input.Our proposed deep learning-based tumor segmentation scheme was successfully applied to multiple types of intracranial tumor (VS, meningioma and BM) undergoing GKRS and for segmenting the tumor effectively from stereotactic MR image volumes for use in GKRS planning.

Background Gamma Knife radiosurgery (GKRS) obliterates 65% to 82% of brain arteriovenous malformations (BAVMs). Objective To explore the impact of hemodynamics on GKRS outcomes. Methods We retrospectively (2011-2017) included 98 patients with BAVMs who had received GKRS alone. Two evaluators, blinded to the outcomes, analyzed the pre-GKRS angiography and magnetic resonance images to obtain the morphological characteristics and quantitative digital subtraction angiography (QDSA) parameters. The venous stasis index was defined as the inflow gradient divided by the absolute value of the outflow gradient. Patients' follow-up magnetic resonance or digital subtraction angiography images were evaluated for the presence of complete obliteration (CO). Cox regression and Kaplan-Meier analyses were conducted to determine the correlations between the parameters and outcomes. Results Among the 98 patients, 63 (63.4%) achieved CO after GKRS at a median latency period of 31 mo. In multivariable analyses with adjustments for age and sex, increased BAVM volume (hazard ratio (HR) 0.949, P = .022) was an independent characteristic predictor, and venous stenosis (HR 2.595, P = .009), venous rerouting (HR 0.375, P = .022), and larger stasis index (HR 1.227, P = .025) were independent angiographic predictors of CO. BAVMs with a stasis index of >1.71 had a higher 36-mo probability of CO than those with a stasis index of ≤1.71 (61.1% vs 26.7%, P Conclusion BAVMs with a larger stasis index, indicating more stagnant venous outflow, may predict obliteration after GKRS. QDSA analysis may help in predicting BAVM treatment outcomes and making therapeutic decisions.