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Hu YS, Yang HC, Lin CJ, Lee CC, Guo WY, Luo CB, Liu KD, Chung WY, Wu HM. Imaging Markers Associated With Radiation-Induced Changes in Brain Arteriovenous Malformations After Radiosurgery. Neurosurgery 2022; 90:464-474. [PMID: 35080514 DOI: 10.1227/neu.0000000000001864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 10/03/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Radiation-induced changes (RICs) in brain tissue, seen as increased perinidal T2-weighted hyperintensity on MRI, are commonly observed in patients with brain arteriovenous malformations (BAVMs) within 2 years after Gamma Knife (Elekta) radiosurgery (GKRS). OBJECTIVE To explore the imaging markers associated with RICs in patients with BAVMs. METHODS We retrospectively included 106 treatment-naïve patients with BAVMs who received GKRS alone between 2011 and 2018 and had ≥24 months of clinical and MRI follow-up. Pre-GKRS angiography and MRIs were analyzed for morphological characteristics and quantitative digital subtraction angiography parameters. RIC severity was categorized as mild (grade I), moderate (grade II), or severe (grade III). Firth logistic regression analysis was conducted to determine the associations between the parameters and RICs. RESULTS Among the 106 patients, 83 (78.3%) developed RICs, with 16 categorized as grade I, 62 as grade II, and 5 as grade III. RICs were symptomatic in 19 patients (17.9%). In multivariable models, BAVMs with a volume of >5 cm3 (odds ratio [OR]: 4.322, P = .024) and neoangiogenesis on angiography before treatment (OR: 3.846, P = .029), and thrombus within nidus or drainage vein on follow-up MRI (OR: 3.679, P = .001) were independently associated with grade II or III RICs. Symptomatic RICs were more likely to develop in basal ganglia or brainstem. CONCLUSION Large BAVMs and neoangiogenesis were associated with moderate to severe RICs in treatment-naïve patients with BAVMs. Our findings may assist with the complication risk assessment for these patients.
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Li CC, Wu MY, Sun YC, Chen HH, Wu HM, Fang ST, Chung WY, Guo WY, Lu HHS. Ensemble classification and segmentation for intracranial metastatic tumors on MRI images based on 2D U-nets. Sci Rep 2021; 11:20634. [PMID: 34667233 PMCID: PMC8526612 DOI: 10.1038/s41598-021-99984-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 10/01/2021] [Indexed: 12/21/2022] Open
Abstract
The extraction of brain tumor tissues in 3D Brain Magnetic Resonance Imaging (MRI) plays an important role in diagnosis before the gamma knife radiosurgery (GKRS). In this article, the post-contrast T1 whole-brain MRI images had been collected by Taipei Veterans General Hospital (TVGH) and stored in DICOM format (dated from 1999 to 2018). The proposed method starts with the active contour model to get the region of interest (ROI) automatically and enhance the image contrast. The segmentation models are trained by MRI images with tumors to avoid imbalanced data problem under model construction. In order to achieve this objective, a two-step ensemble approach is used to establish such diagnosis, first, classify whether there is any tumor in the image, and second, segment the intracranial metastatic tumors by ensemble neural networks based on 2D U-Net architecture. The ensemble for classification and segmentation simultaneously also improves segmentation accuracy. The result of classification achieves a F1-measure of [Formula: see text], while the result of segmentation achieves an IoU of [Formula: see text] and a DICE score of [Formula: see text]. Significantly reduce the time for manual labeling from 30 min to 18 s per patient.
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Sun YC, Hsieh AT, Fang ST, Wu HM, Kao LW, Chung WY, Chen HH, Liou KD, Lin YS, Guo WY, Lu HHS. Can 3D artificial intelligence models outshine 2D ones in the detection of intracranial metastatic tumors on magnetic resonance images? J Chin Med Assoc 2021; 84:956-962. [PMID: 34613943 DOI: 10.1097/jcma.0000000000000614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
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.
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Sun Y, Fan LY, Huang CT, Liu CC, Chen TF, Lu CJ, Guo WY, Chang YC, Chiu MJ. Prognostic Features of Sporadic Creutzfeldt-Jakob Disease: An Analysis of Taiwan's Nationwide Surveillance. J Am Med Dir Assoc 2021; 23:845-851. [PMID: 34492219 DOI: 10.1016/j.jamda.2021.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To study the prognostic features of Creutzfeldt-Jakob disease (CJD) and shed light on its future therapy. DESIGN Retrospective cohort study of a longitudinal national cohort of the Taiwan Centers for Disease Control. SETTING AND PARTICIPANTS 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. METHODS 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. RESULTS 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. CONCLUSIONS AND IMPLICATIONS 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.
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Chou CL, Chen HH, Yang HC, Chen YW, Chen CJ, Chen YW, Wu HM, Guo WY, Pan DHC, Chung WY, Wong TT, Lee CC. Effects of stereotactic radiosurgery versus conventional radiotherapy on body mass index in patients with craniopharyngioma. J Neurosurg Pediatr 2021; 28:43-49. [PMID: 33990078 DOI: 10.3171/2020.12.peds20165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 12/07/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Hypothalamic obesity is common among patients with craniopharyngioma. This study examined whether precise stereotactic radiosurgery reduces the risk of hypothalamic obesity in cases of craniopharyngioma with expected long-term survival. METHODS This cohort study included 40 patients who had undergone Gamma Knife radiosurgery (GKRS; n = 22) or fractionated radiotherapy (FRT; n = 18) for residual or recurrent craniopharyngioma. Neurological presentations, tumor volume changes, and BMI values were meticulously reviewed. The median clinical follow-up durations were 9.7 years in the GKRS group and 10.8 years in the FRT group. RESULTS The median ages at the time of GKRS and FRT were 9.0 years and 10.0 years, respectively. The median margin dose of GKRS was 12.0 Gy (range 10.0-16.0 Gy), whereas the median dose of FRT was 50.40 Gy (range 44.1-56.3 Gy). Prior to GKRS or FRT, the median BMI values were 20.5 kg/m2 in the GKRS cohort and 20.0 kg/m2 in the FRT cohort. The median BMIs after radiation therapy at final follow-up were 21.0 kg/m2 and 24.0 kg/m2 for the GKRS and FRT cohorts, respectively. In the FRT cohort, BMI curves rapidly increased beyond the 85th percentile of the upper limit of the general population. BMI curves in the GKRS cohort increased more gradually, and many of the patients merged into the normal growth curve after adolescence. However, the observed difference was not statistically significant (p = 0.409). CONCLUSIONS The study compared the two adjuvant radiation modalities most commonly used for recurrent and residual craniopharyngioma. The authors' results revealed that precise radiosurgery dose planning can mediate the subsequent increase in BMI. There is every indication that meticulous GKRS treatment is an effective approach to treating craniopharyngioma while also reducing the risk of hypothalamic obesity.
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Chen KK, Lin CJ, Guo WY, Chu WF, Wu YT. Estimating blood flow velocity using time-resolved 3D angiography and a derived physical law of contrast media. Physiol Meas 2021; 42:025007. [PMID: 33498022 DOI: 10.1088/1361-6579/abe022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Four-dimensional (4D) digital subtraction angiography (DSA) offers a method for evaluating hemodynamics. It is, however, unclear how the delivered contrast medium interacts with the physiological blood flow, and how hemodynamic information may be inferred from the mixture of the contrast medium and blood. In this study, we present a theoretical explanation of contrast dynamics, and an accompanying algorithm for estimating blood flow velocity. APPROACH We retrospectively recruited 23 patients who underwent both 4D DSA and magnetic resonance (MR) phase-contrast imaging. The 4D DSA-reconstructed contrast dynamics were first studied for the internal carotid arteries. Using physical laws governing fluid motion within a curved tube, we showed that the reconstructed contrast dynamics obeyed a simple advection equation. We then proposed an algorithm for estimating the contrast dynamics using angiographic data, and subsequently estimated the axial blood flow velocity using an advection equation. MAIN RESULTS The estimated velocities were compared using three techniques: the Fourier technique, Lin's method, and MR phase contrast. Testing with noise-corrupted artificial data showed that the proposed algorithm was noise resistant. The velocities of 23 patients computed by 4D DSA using the proposed algorithm showed a moderate correlation with the MR phase contrast (r = 0.61), and good correlations with the other two techniques (r = 0.75 and r = 0.72). SIGNIFICANCE The proposed algorithm and has been applied to blood vessel segments with poor signal-to-noise ratios and axial lengths of less than 3 cm, and has a physical basis for computing axial flow velocities using an advection equation. The results of the proposed algorithm are consistent with existing methods.
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Chen ST, Luo CB, Guo WY, Chang FC. Endovascular management of symptomatic stenosis of supra-aortic arteries in patients with Takayasu arteritis. J Chin Med Assoc 2021; 84:303-308. [PMID: 33350653 DOI: 10.1097/jcma.0000000000000479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Endovascular management is used to treat Takayasu arteritis (TA) involving the supra-aortic branches. However, the long-term outcome of this treatment remains unclear. Here, technical safety, outcomes, and restenosis management of supra-aortic arteries in TA patients receiving endovascular treatment were evaluated. METHODS TA patients with symptomatic supra-aortic stenosis who underwent percutaneous angioplasty and stenting between 2008 and 2018 at our institute were enrolled in this study. Pre- and post-procedural magnetic resonance imaging (MRI) evaluations, including high-resolution vessel wall imaging (HR-VWI), were performed. Technical efficacy, peri-procedural complications, early post-procedural MRI results, and stent patency were examined. RESULTS All six patients successfully received stent placement or percutaneous transluminal angioplasty in a total of 22 treated arteries without neurologic complications. During follow-up (mean, 56.3 ± 41.1 months), no recurrent stroke occurred, yet significant restenosis developed in 12 of 22 (54.5%) of the treated arteries. Three of the patients underwent HR-VWI before surgery. Concentric wall thickening and enhancement of the left common carotid artery was detected in one patient, indicating acute inflammation. Angioplasty with drug-eluting balloon (DEB) successfully treated a case of refractory restenosis. Among 10 early post-procedure MRI performed, only two asymptomatic new lesions were detected with diffusion-weighted imaging. CONCLUSION Endovascular treatment of supra-aortic arteries of TA patients was safe and effective, yet was associated with a high restenosis rate. Thus, close follow-up is needed. HR-VWI is helpful for pre-procedural selection of patients for percutaneous angioplasty and stenting and drug-eluting balloon angioplasty appears to be a promising treatment for refractory in-stent restenosis.
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Lee CC, Lee WK, Wu CC, Lu CF, Yang HC, Chen YW, Chung WY, Hu YS, Wu HM, Wu YT, Guo WY. Applying artificial intelligence to longitudinal imaging analysis of vestibular schwannoma following radiosurgery. Sci Rep 2021; 11:3106. [PMID: 33542422 PMCID: PMC7862268 DOI: 10.1038/s41598-021-82665-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 01/18/2021] [Indexed: 02/06/2023] Open
Abstract
Artificial intelligence (AI) has been applied with considerable success in the fields of radiology, pathology, and neurosurgery. It is expected that AI will soon be used to optimize strategies for the clinical management of patients based on intensive imaging follow-up. Our objective in this study was to establish an algorithm by which to automate the volumetric measurement of vestibular schwannoma (VS) using a series of parametric MR images following radiosurgery. Based on a sample of 861 consecutive patients who underwent Gamma Knife radiosurgery (GKRS) between 1993 and 2008, the proposed end-to-end deep-learning scheme with automated pre-processing pipeline was applied to a series of 1290 MR examinations (T1W+C, and T2W parametric MR images). All of which were performed under consistent imaging acquisition protocols. The relative volume difference (RVD) between AI-based volumetric measurements and clinical measurements performed by expert radiologists were + 1.74%, - 0.31%, - 0.44%, - 0.19%, - 0.01%, and + 0.26% at each follow-up time point, regardless of the state of the tumor (progressed, pseudo-progressed, or regressed). This study outlines an approach to the evaluation of treatment responses via novel volumetric measurement algorithm, and can be used longitudinally following GKRS for VS. The proposed deep learning AI scheme is applicable to longitudinal follow-up assessments following a variety of therapeutic interventions.
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Chien C, Lin CJ, Chang FC, Chung CP, Lin CJ, Liu HY, Chi NF, Hsu LC, Tang CW, Guo WY, Luo CB, Lai YJ, Lee IH. Quantitative CT angiography predicts large artery occlusion types and successful thrombectomy in acute ischemic stroke. J Chin Med Assoc 2021; 84:61-67. [PMID: 32956106 DOI: 10.1097/jcma.0000000000000434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Clinical and radiological outcomes of endovascular thrombectomy (EVT) are related to etiologies of large vessel occlusion (LVO) in acute stroke. However, preprocedural computed tomography angiography (CTA) or CT perfusion imaging can hardly distinguish embolic occlusion from atherosclerotic occlusion. We hypothesized that quantitative multiphase CTA (mCTA) of LVO may predict occlusion types and thrombectomy outcome. METHODS We retrospectively evaluated the consecutive stroke patients who had undergone mCTA and EVT <6 hours of onset at two independent medical centers. The intra-arterial radiodensities of Hounsfield unit (HU) were measured to examine the HUdistal/proximal ratio using receiver operating characteristic curve analysis. The derived cut-off value was re-examined in an independent cohort. RESULTS In the derivation cohort (n = 102), 81 patients (79.4%) were embolic occlusion without severe residual intracranial atherosclerotic stenosis (ICAS[-]) and 21 patients were atherosclerosis-related occlusion (ICAS[+]) based on digital subtraction angiography (DSA). The optimal cut-off to predict embolic occlusion was HU ratio <0.6 measured at 2 mm from the occlusion site (maximum area under the curve = 0.87; sensitivity 96%; specificity 81%). This cut-off also independently predicted successful recanalization using stent-retrievers and/or contact aspiration (modified Treatment in Cerebral Ischemia score ≥2b; p = 0.002) after adjusting for age, atrial fibrillation, and collateral circulation score, but not predicted favorable outcome at 3 months post stroke. Importantly, in the validation cohort (n = 95, 80% embolic occlusion), this HU ratio cut-off similarly predicted occlusion types and recanalization outcome, respectively. CONCLUSION The mCTA-based quantitative radiodensities of acute LVO provides preprocedural predictive values of DSA-determined occlusion types and thrombectomy outcomes.
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Chen JH, Wu MH, Luo CB, Lirng JF, Chen ST, Wu CH, Guo WY, Chang FC. Long-term imaging follow-up to evaluate restenosis in patients with carotid stenosis after angioplasty and stenting. J Chin Med Assoc 2021; 84:87-94. [PMID: 32773586 DOI: 10.1097/jcma.0000000000000405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
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.
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Yang HC, Peng SJ, Lee CC, Wu HM, Chen YW, Lin CJ, Shiau CY, Guo WY, Pan DHC, Liu KD, Chung WY, Lin YY. Does the Diffuseness of the Nidus Affect the Outcome of Stereotactic Radiosurgery in Patients with Unruptured Cerebral Arteriovenous Malformations? Stereotact Funct Neurosurg 2020; 99:113-122. [PMID: 33264796 DOI: 10.1159/000510683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/31/2020] [Indexed: 11/19/2022]
Abstract
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.
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Yang HC, Wu CC, Lee CC, Huang HE, Lee WK, Chung WY, Wu HM, Guo WY, Wu YT, Lu CF. Prediction of pseudoprogression and long-term outcome of vestibular schwannoma after Gamma Knife radiosurgery based on preradiosurgical MR radiomics. Radiother Oncol 2020; 155:123-130. [PMID: 33161011 DOI: 10.1016/j.radonc.2020.10.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND PURPOSE Gamma Knife radiosurgery (GKRS) is a safe and effective treatment modality with a long-term tumor control rate over 90% for vestibular schwannoma (VS). However, numerous tumors may undergo a transient pseudoprogression during 6-18 months after GKRS followed by a long-term volume reduction. The aim of this study is to determine whether the radiomics analysis based on preradiosurgical MRI data could predict the pseudoprogression and long-term outcome of VS after GKRS. MATERIALS AND METHODS A longitudinal dataset of patients with VS treated by single GKRS were retrospectively collected. Overall 336 patients with no previous craniotomy for tumor removal and a median of 65-month follow-up period after radiosurgery were finally included in this study. In total 1763 radiomic features were extracted from the multiparameteric MRI data before GKRS followed by the machine-learning classification. RESULTS We constructed a two-level machine-learning model to predict the long-term outcome and the occurrence of transient pseudoprogression after GKRS separately. The prediction of long-term outcome achieved an accuracy of 88.4% based on five radiomic features describing the variation of T2-weighted intensity and inhomogeneity of contrast enhancement in tumor. The prediction of transient pseudoprogression achieved an accuracy of 85.0% based on another five radiomic features associated with the inhomogeneous hypointensity pattern of contrast enhancement and the variation of T2-weighted intensity. CONCLUSION The proposed machine-learning model based on the preradiosurgical MR radiomics provides a potential to predict the pseudoprogression and long-term outcome of VS after GKRS, which can benefit the treatment strategy in clinical practice.
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Sun Y, Liu CC, Fan LY, Huang CT, Chen TF, Lu CJ, Guo WY, Chang YC, Chiu MJ. Incidence of and Mortality Due to Human Prion Diseases in Taiwan: A Prospective 20-Year Nationwide Surveillance Study from 1998 to 2017. Clin Epidemiol 2020; 12:1073-1081. [PMID: 33116901 PMCID: PMC7569055 DOI: 10.2147/clep.s274093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/23/2020] [Indexed: 12/16/2022] Open
Abstract
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.
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Lin CJ, Luo CB, Chien C, Chang FC, Lin CJ, Lee IH, Hsu LC, Chung CP, Liu HY, Chi NF, How CK, Wang SJ, Guo WY, Lin YY. Better endovascular mechanical thrombectomy outcome in atrial fibrillation patients with acute ischemic stroke: A single-center experience. J Chin Med Assoc 2020; 83:756-760. [PMID: 32649411 DOI: 10.1097/jcma.0000000000000377] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Endovascular thrombectomy (EVT) has become the standard treatment for acute ischemic stroke with large vessel occlusion. Atrial fibrillation (AF) is one of the major causes. However, the impact of AF on the treatment has not yet been clearly discussed. This study is to evaluate the influence of AF on the outcomes of EVT in patients with acute ischemic stroke. METHODS Data from our Stroke Registry Database from April 2015 to July 2018 were reviewed. Technical efficacy, functional, and safety outcomes were reported and compared between patients with and without AF. A multivariate logistic regression model was performed to identify the predictors of the good functional outcome. RESULTS We reviewed 83 eligible patients receiving EVT. Patients (51.8%) were eventually found to have AF. The substantial reperfusion rate (modified thrombolysis in cerebral infarction 2b-3) was 72.1% and 55.0% in patients with and without AF, respectively, inclusive of a learning curve (p = 0.12). The good functional outcome (90-day modified Rankin scale: 0 to 2) rate was 55.8% and 17.5% in patients with and without AF, respectively (p < 0.01). A multivariable logistic regression analysis showed that age <70 years, the substantial reperfusion, and the presence of AF were three significant predictors for a good functional outcome. CONCLUSION Our study showed that patients with AF responded significantly better to EVT than those without AF did. Intracranial atherosclerotic diseases in patients without AF which were especially refractory to EVT may contribute to the difference of the functional outcomes between the two groups.
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Karlsson B, Jokura H, Yang HC, Yamamoto M, Martinez R, Kawagishi J, Guo WY, Beute G, Chung WY, Söderman M, Yeo TT. Clinical outcome following cerebral AVM hemorrhage. Acta Neurochir (Wien) 2020; 162:1759-1766. [PMID: 32385636 DOI: 10.1007/s00701-020-04380-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 04/29/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND A significant difference exists between the published results reporting the clinical outcome following brain arteriovenous malformation (AVM) ruptures. Information about the outcome following hemorrhage in an AVM population treated with radiosurgery could provide additional information to assess the risk of mortality and morbidity following an AVM hemorrhage. METHODS Clinical outcome was studied in 383 patients, the largest patient population yet studied, who suffered from a symptomatic hemorrhage after Gamma Knife® surgery (GKS) but before confirmed AVM obliteration. The impact of different patient, AVM, and treatment parameters on the clinical outcome was analyzed. The aim was to generate outcome predictions by comparing our data to and combining them with earlier published results. RESULTS No relation was found between clinical outcome and treatment parameters, indicating that the results are applicable also on untreated AVMs. Twenty-one percent of the patients died, 45% developed or experienced worsening of neurological sequelae, and 35% recovered completely after the hemorrhage. Old age was a predictor of poor outcome. Sex, AVM location, AVM volume, and history of prior hemorrhage did not influence the outcome. The mortality rate was comparable to earlier published prospective data, but higher than that found in retrospective studies. CONCLUSIONS The mortality rates in earlier published retrospective series as well as in studies focusing on clinical outcome following AVM hemorrhage significantly underestimate the risk for a mortal outcome following an AVM hemorrhage. Based on our findings, an AVM rupture has around 20% likelihood to result in mortality, 45% likelihood to result in a minor or major deficit, and 35% likelihood of complete recovery. The findings are probably applicable also for AVM ruptures in general. The cumulative mortality and morbidity rates 25 years after diagnosis were estimated to be around 40% in a patient with a patent AVM.
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Lee WK, Wu CC, Lee CC, Lu CF, Yang HC, Huang TH, Lin CY, Chung WY, Wang PS, Wu HM, Guo WY, Wu YT. Combining analysis of multi-parametric MR images into a convolutional neural network: Precise target delineation for vestibular schwannoma treatment planning. Artif Intell Med 2020; 107:101911. [PMID: 32828450 DOI: 10.1016/j.artmed.2020.101911] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/22/2020] [Accepted: 06/09/2020] [Indexed: 11/30/2022]
Abstract
Manual delineation of vestibular schwannoma (VS) by magnetic resonance (MR) imaging is required for diagnosis, radiosurgery dose planning, and follow-up tumor volume measurement. A rapid and objective automatic segmentation method is required, but problems have been encountered due to the low through-plane resolution of standard VS MR scan protocols and because some patients have non-homogeneous cystic areas within their tumors. In this study, we retrospectively collected multi-parametric MR images from 516 patients with VS; these were extracted from the Gamma Knife radiosurgery planning system and consisted of T1-weighted (T1W), T2-weighted (T2W), and T1W with contrast (T1W + C) images. We developed an end-to-end deep-learning-based method via an automatic preprocessing pipeline. A two-pathway U-Net model involving two sizes of convolution kernel (i.e., 3 × 3 × 1 and 1 × 1 × 3) was used to extract the in-plane and through-plane features of the anisotropic MR images. A single-pathway model that adopted the same architecture as the two-pathway model, but used a kernel size of 3 × 3 × 3, was also developed for comparison purposes. In addition, we used multi-parametric MR images with different image contrasts as the model training input in order to effectively segment tumors with solid as well as cystic parts. The results of the automatic segmentation demonstrated that (1) the two-pathway model outperformed single-pathway model in terms of dice scores (0.90 ± 0.05 versus 0.87 ± 0.07); both of them having been trained using the T1W, T1W + C and T2W anisotropic MR images, (2) the optimal single-parametric two-pathway model (dice score: 0.88 ± 0.06) was then trained using the T1W + C images, and (3) the two-pathway models trained using bi-parametric (T1W + C and T2W) and tri-parametric (T1W, T2W, and T1W + C) images outperformed the model trained using the single-parametric (T1W + C) images (dice scores: 0.89 ± 0.05 and 0.90 ± 0.05, respectively, larger than 0.88 ± 0.06) because it showed improved segmentation of the non-homogeneous parts of the tumors. The proposed two-pathway U-Net model outperformed the single-pathway U-Net model when segmenting VS using anisotropic MR images. The multi-parametric models effectively improved on the defective segmentation obtained using the single-parametric models by separating the non-homogeneous tumors into their solid and cystic parts.
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Lin YY, Wu HM, Yang HC, Chen CJ, Lin CJ, Chen YW, Chen HH, Wong TT, Hu YS, Chung WY, Shiau CY, Guo WY, Pan DHC, Lee CC. Repeated gamma knife radiosurgery enables longer tumor control in cases of highly-recurrent intracranial ependymoma. J Neurooncol 2020; 148:363-372. [PMID: 32405998 DOI: 10.1007/s11060-020-03531-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/05/2020] [Indexed: 11/24/2022]
Abstract
PURPOSE 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. METHODS 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. RESULTS 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). CONCLUSIONS Repeated GKRS appeared to be an effective treatment strategy for recurrent or residual intracranial ependymomas, with acceptable complication rates.
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Yu KW, Lin CJ, Luo CB, Lin YY, Guo WY, Chang FC, Lee IH, Lin CJ, Chung CP, Chien C. Single-phase computed tomography angiography sufficiently predicts outcomes after mechanical thrombectomy. J Chin Med Assoc 2020; 83:478-483. [PMID: 32217991 DOI: 10.1097/jcma.0000000000000300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Arterial collateral (AC) assessed by single-phase computed tomography angiography (CTA) or multiphase CTA has been used to predict clinical outcomes in patients undergoing mechanical thrombectomy (MT). Recently, venous opacification (VO) was proposed as another accurate image marker. This study aimed to compare the efficacy using AC and VO as predictors of MT outcome. METHODS Patients with occlusion of the proximal anterior circulation undergoing MT were included retrospectively. We assessed the AC status respectively according to different methods: modified Tan score, Miteff score in single-phase CTA, and pial arterial filling score in multiphase CTA. VO was assessed according to cortical vein opacification score. Favorable clinical outcome was defined as modified Rankin Scale 0-2 90 days after MT. Logistic regression models were established and receiver operating characteristics curve were used to determine the predictability of favorable outcome in patients with adequate AC and VO. RESULTS A total of 75 patients were enrolled. Adequate AC identified by modified Tan score (odds ratio, 7.3; p < 0.001), Miteff score (odds ratio, 4.5; p = 0.009), significantly predicted favorable outcome, but not adequate VO. The area under the curve was largest for adequate AC in model of modified Tan score 0.730 (95% CI, 0.60-0.86), while adequate VO showed the least area under the curve: 0.577 (95% CI, 0.43-0.73). CONCLUSION We considered adequate AC in single-phase CTA could be reliable enough as an imaging marker rather than adequate VO to predict favorable outcome after MT.
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Hu YS, Lee CC, Guo WY, Lin CJ, Yang HC, Wu HM, Liu KD, Chung WY. Trigeminal Nerve Atrophy Predicts Pain Recurrence After Gamma Knife Stereotactic Radiosurgery for Classical Trigeminal Neuralgia. Neurosurgery 2020; 84:927-934. [PMID: 29660047 DOI: 10.1093/neuros/nyy122] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/13/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Trigeminal nerve atrophy and neurovascular compression (NVC) are frequently observed in classical trigeminal neuralgia (CTN). OBJECTIVE To determine whether nerve characteristics contribute to Gamma Knife (Elekta AB, Stockholm, Sweden) surgery (GKS) outcomes in unilateral CTN without previous surgery. METHODS From 2006 to 2012, 67 patients with unilateral CTN without previous surgery received GKS with a maximal dose of 90 Gy delivered to the trigeminal nerve juxta brainstem. Two evaluators, blinded to the side of pain, analyzed the magnetic resonance images before GKS to obtain the parameters, including nerve cross-sectional area (CSA), vessel type of NVC, and site of NVC along the nerve. Correlations of the parameters with pain relief (Barrow Neurological Institute [BNI] grades I-IIIb) and recurrence (BNI grades VI-V) were made by using Cox regression and Kaplan-Meier analyses. RESULTS The median CSA of the symptomatic nerves was significantly smaller than that of the asymptomatic nerves (4.95 vs 5.9 mm2, P < .001). After adjustment for age and sex, larger nerve CSA was associated with lower initial pain relief (hazard ratio 0.81, P = .03) and lower pain recurrence after initial response (hazard ratio 0.58, P = .02). Patients with nerve atrophy (CSA of ≤ 4.4 mm2 after receiver operating characteristic curve analysis) had a lower 5-yr probability of maintaining pain relief after initial response than those without nerve atrophy (65% vs 86%, P = .04). CONCLUSION Trigeminal nerve atrophy may predict pain recurrence in patients with initial post-GKS relief of CTN. Arterial and proximal NVC are not predictive of GKS outcomes. Future studies are required to determine optimal treatments for long-term pain relief in patients with CTN and trigeminal nerve atrophy.
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Hu YS, Guo WY, Lin CJ, Wu HM, Luo CB, Wu CA, Lee CC, Yang HC, Liu KD, Chung WY. Magnetic resonance imaging as a single diagnostic tool for verifying radiosurgery outcomes of cavernous sinus dural arteriovenous fistula. Eur J Radiol 2020; 125:108866. [PMID: 32065928 DOI: 10.1016/j.ejrad.2020.108866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 01/24/2020] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE MRI and MR angiography (MRA) are noninvasive methods for examining cavernous sinus dural arteriovenous fistulas (CSDAVFs) after radiosurgery. In this study, we investigated the accuracy of unenhanced MRI/3-dimensional time-of-flight (3D TOF) MRA in evaluating CSDAVF obliteration as compared with digital subtraction angiography (DSA). METHODS From 1995-2012, 48 cases of CSDAVFs received Gamma Knife surgery (GKS) and had undergone both unenhanced MRI/3D TOF MRA and DSA for posttreatment evaluation. Two blinded observers independently interpreted the results of MRI/MRA. The results of MRI/MRA were compared with those of DSA. The sensitivity (the probability of MRI/MRA showing obliteration when DSA showed complete obliteration), specificity, positive predictive value, and negative predictive value for CSDAVF obliteration were reported. RESULTS The median interval between the final MRI/MRA and the subsequent DSA was 2 months. Follow-up DSA revealed that 38 of 48 (79.2 %) CSDAVFs were completely obliterated. The results of interobserver agreement assessment showed almost perfect agreement between the 2 observers. For unenhanced MRI/3D TOF MRA, the observed sensitivity was 84.2 %, specificity was 100 %, positive predictive value was 100 %, and negative predictive value was 62.5 %. CONCLUSIONS Unenhanced MRI/3D TOF MRA alone may be adequate to document the complete obliteration of CSDAVFs after GKS. Time-resolved MRA or DSA can be reserved for a suspected residual CSDAVF after a sufficient latency period after GKS.
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Huang CY, Lee CC, Yang HC, Lin CJ, Wu HM, Chung WY, Shiau CY, Guo WY, Pan DHC, Peng SJ. Radiomics as prognostic factor in brain metastases treated with Gamma Knife radiosurgery. J Neurooncol 2020; 146:439-449. [PMID: 32020474 DOI: 10.1007/s11060-019-03343-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/12/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE Gamma Knife radiosurgery (GKRS) is a non-invasive procedure for the treatment of brain metastases. This study sought to determine whether radiomic features of brain metastases derived from pre-GKRS magnetic resonance imaging (MRI) could be used in conjunction with clinical variables to predict the effectiveness of GKRS in achieving local tumor control. METHODS We retrospectively analyzed 161 patients with non-small cell lung cancer (576 brain metastases) who underwent GKRS for brain metastases. The database included clinical data and pre-GKRS MRI. Brain metastases were demarcated by experienced neurosurgeons, and radiomic features of each brain metastasis were extracted. Consensus clustering was used for feature selection. Cox proportional hazards models and cause-specific proportional hazards models were used to correlate clinical variables and radiomic features with local control of brain metastases after GKRS. RESULTS Multivariate Cox proportional hazards model revealed that higher zone percentage (hazard ratio, HR 0.712; P = .022) was independently associated with superior local tumor control. Similarly, multivariate cause-specific proportional hazards model revealed that higher zone percentage (HR 0.699; P = .014) was independently associated with superior local tumor control. CONCLUSIONS The zone percentage of brain metastases, a radiomic feature derived from pre-GKRS contrast-enhanced T1-weighted MRIs, was found to be an independent prognostic factor of local tumor control following GKRS in patients with non-small cell lung cancer and brain metastases. Radiomic features indicate the biological basis and characteristics of tumors and could potentially be used as surrogate biomarkers for predicting tumor prognosis following GKRS.
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Lee CC, Wang WH, Yang HC, Lin CJ, Wu HM, Lin YY, Hu YS, Chen CJ, Chen YW, Chou CC, Liu YT, Chung WY, Shiau CY, Guo WY, Hung-Chi Pan D, Hsu SPC. Gamma Knife radiosurgery for cerebral cavernous malformation. Sci Rep 2019; 9:19743. [PMID: 31874979 PMCID: PMC6930272 DOI: 10.1038/s41598-019-56119-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/02/2019] [Indexed: 11/28/2022] Open
Abstract
This is a retrospective study examining the efficacy and safety of Gamma Knife radiosurgery (GKS) in treating patients with cerebral cavernous malformations (CCMs). Between 1993 and 2018, 261 patients with 331 symptomatic CCMs were treated by GKS. The median age was 39.9 years and females were predominant (54%). The median volume of CCMs was 3.1 mL. The median margin dose was 11.9 Gy treat to a median isodose level of 59%. Median clinical and imaging follow-up times were 69 and 61 months, respectively. After the initial hemorrhage that led to CCM diagnosis, 136 hemorrhages occurred in the period prior to GKS (annual incidence = 23.6%). After GKS, 15 symptomatic hemorrhages occurred within the first 2 years of follow-up (annual incidence = 3.22%), and 37 symptomatic hemorrhages occurred after the first 2 years of follow-up (annual incidence = 3.16%). Symptomatic radiation-induced complication was encountered in 8 patients (3.1%). Mortality related to GKS occurred in 1 patient (0.4%). In conclusion, GKS decreased the risk of hemorrhage in CCM patients presenting with symptomatic hemorrhage. GKS is a viable alternative treatment option for patients with surgically-inaccessible CCMs or significant medical comorbidities.
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Hu YS, Lee CC, Wu HM, Yang HC, Lin TM, Luo CB, Guo WY, Chung WY, Lin CJ. Stagnant Venous Outflow Predicts Brain Arteriovenous Malformation Obliteration After Gamma Knife Radiosurgery Without Prior Intervention. Neurosurgery 2019; 87:338-347. [DOI: 10.1093/neuros/nyz507] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 09/10/2019] [Indexed: 11/14/2022] Open
Abstract
Abstract
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 < .001).
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.
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Karlsson B, Johansson AV, Yang HC, Jokura H, Yamamoto M, Martínez-Álvarez R, Kawagishi J, Guo WY, Beute G, Pan DHC, Chung WY, Söderman M, Aiyama H, Yeo TT. A novel method to determine the natural course of unruptured brain arteriovenous malformations without the need for follow-up information. J Neurosurg 2019; 129:10-16. [PMID: 30544301 DOI: 10.3171/2018.7.gks181278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/11/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVEThere is a strong clinical need to accurately determine the average annual hemorrhage risk in unruptured brain arteriovenous malformations (AVMs). This need motivated the present initiative to use data from a uniquely large patient population and design a novel methodology to achieve a risk determination with unprecedented accuracy. The authors also aimed to determine the impact of sex, pregnancy, AVM volume, and location on the risk for AVM rupture.METHODSThe present study does not consider any specific management of the AVMs, but only uses the age distribution for the first hemorrhage, the shape of which becomes universal for a sufficiently large set of patients. For this purpose, the authors collected observations, including age at first hemorrhage and AVM size and location, in 3425 patients. The average annual risk for hemorrhage could then be determined from the simple relation that the number of patients with their first hemorrhage at a specific age equals the risk for hemorrhage times the number of patients at risk at that age. For a subset of the patients, the information regarding occurrence of AVM hemorrhage after treatment of the first hemorrhage was used for further analysis of the influence on risk from AVM location and pregnancy.RESULTSThe age distribution for the first AVM hemorrhage was used to determine the average annual risk for hemorrhage in unruptured AVMs at adult ages (25-60 years). It was concluded to be 3.1% ± 0.2% and unrelated to AVM volume but influenced by its location, with the highest risk for centrally located AVMs. The hemorrhage risk was found to be significantly higher for females in their fertile years.CONCLUSIONSThe present methodology allowed the authors to determine the average annual risk for the first AVM hemorrhage at 3.1% ± 0.2% without the need for individual patient follow-up. This methodology has potential also for other similar types of investigations. The conclusion that centrally located AVMs carry a higher risk was confirmed by follow-up information. Follow-up information was also used to conclude that pregnancy causes a substantially greater AVM hemorrhage risk. The age distribution for AVM hemorrhage is incompatible with AVMs present at birth having the same hemorrhage risk as AVMs in adults. Plausibly, they instead develop in the early years of life, possibly with a lower hemorrhage risk during that time period.
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Lee CC, Hsu SPC, Lin CJ, Wu HM, Chen YW, Luo YH, Chiang CL, Hu YS, Chung WY, Shiau CY, Guo WY, Hung-Chi Pan D, Yang HC. Epidermal growth factor receptor mutations: association with favorable local tumor control following Gamma Knife radiosurgery in patients with non-small cell lung cancer and brain metastases. J Neurosurg 2019; 133:313-320. [PMID: 31226692 DOI: 10.3171/2019.4.jns19446] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 04/03/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The presence of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) has been associated with elevated radiosensitivity in vitro. However, results from clinical studies on radiosensitivity in cases of NSCLC with EGFR mutations are inconclusive. This paper presents a retrospective analysis of patients with NSCLC who underwent regular follow-up imaging after radiotherapy for brain metastases (BMs). The authors also investigated the influence of EGFR mutations on the efficacy of Gamma Knife radiosurgery (GKRS). METHODS This study included 264 patients (1069 BMs) who underwent GKRS treatment and for whom EGFR mutation status, demographics, performance status, and tumor characteristics were available. Radiological images were obtained at 3 months after GKRS and at 3-month intervals thereafter. Kaplan-Meier plots and Cox regression analysis were used to correlate EGFR mutation status and other clinical features with tumor control and overall survival. RESULTS The tumor control rates and overall 12-month survival rates were 87.8% and 65.5%, respectively. Tumor control rates in the EGFR mutant group versus the EGFR wild-type group were 90.5% versus 79.4% at 12 months and 75.0% versus 24.5% at 24 months. During the 2-year follow-up period after SRS, the intracranial response rate in the EGFR mutant group was approximately 3-fold higher than that in the wild-type group (p < 0.001). Cox regression multivariate analysis identified EGFR mutation status, extracranial metastasis, primary tumor control, and prescribed margin dose as predictors of tumor control (p = 0.004, p < 0.001, p = 0.004, and p = 0.026, respectively). Treatment with a combination of GKRS and tyrosine kinase inhibitors (TKIs) was the most important predictor of overall survival (p < 0.001). CONCLUSIONS The current study demonstrated that, among patients with NSCLC-BMs, EGFR mutations were independent prognostic factors of tumor control. It was also determined that a combination of GKRS and TKI had the most pronounced effect on prolonging survival after SRS. In select patient groups, treatment with SRS in conjunction with EGFR-TKIs provided effective tumor control for NSCLC-BMs.
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