Stagnant Venous Outflow Predicts Brain Arteriovenous Malformation Obliteration After Gamma Knife Radiosurgery Without Prior Intervention

Neurosurgery ◽  
2019 ◽  
Vol 87 (2) ◽  
pp. 338-347 ◽  
Author(s):  
Yong-Sin Hu ◽  
Cheng-Chia Lee ◽  
Hsiu-Mei Wu ◽  
Huai-Che Yang ◽  
Te-Ming Lin ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Digital Subtraction Angiography ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Magnetic Resonance Images ◽  
Venous Stasis ◽  
Digital Subtraction ◽  
Venous Outflow ◽  
Therapeutic Decisions ◽  
The Impact

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.

Texture Analysis of Standard Magnetic Resonance Images to Predict Response to Gamma Knife Radiosurgery in Vestibular Schwannomas

2019 ◽  
Vol 132 ◽  
pp. e228-e234
Author(s):  
Herwin Speckter ◽  
Jairo Santana ◽  
José Bido ◽  
Giancarlo Hernandez ◽  
Diones Rivera ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Texture Analysis ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Magnetic Resonance Images ◽  
Vestibular Schwannomas

GAMMA KNIFE RADIOSURGERY–INDUCED CAVERNOUS HEMANGIOMA

Neurosurgery ◽  
2009 ◽  
Vol 64 (5) ◽  
pp. E1006-E1007 ◽  
Author(s):  
Yasuo Sasagawa ◽  
Takuya Akai ◽  
Shoutarou Itou ◽  
Hideaki Iizuka
Keyword(s):  
Magnetic Resonance ◽  
Gamma Knife ◽  
Cavernous Hemangioma ◽  
Rare Case ◽  
Gamma Knife Radiosurgery ◽  
Magnetic Resonance Images ◽  
Weighted Image ◽  
Resected Tumor ◽  
Radiation Induced

Abstract OBJECTIVE We report a rare case of gamma knife radiation–induced cavernous hemangioma. CLINICAL PRESENTATION A 35-year-old man underwent resection of a left vestibular schwannoma and gamma knife radiosurgery (maximal dose, 24 Gy; marginal dose, 12 Gy) for the residual schwannoma. Follow-up magnetic resonance images showed no tumor progression. Ten years later, he developed right hemihyperesthesia and mild hemiparesis. Magnetic resonance imaging revealed a size reduction at the resected tumor site and a newly developed lesion in the adjacent pons. No connection was observed between the new mass and the previous tumor. The T2-weighted image showed the new mass as heterogeneous and “popcorn-like” with a mixed signal intensity core and a hypointense hemosiderin rim. Two years after its appearance, the new lesion appeared hypointense on the T2-weighted image, with a hyperintense core on the T1-weighted image. These findings were compatible with cavernous hemangioma. INTERVENTION We diagnosed the new lesion as a radiation-induced cavernous hemangioma. Ten days after admission, symptoms improved without surgical intervention. CONCLUSION Gamma knife radiosurgery induced this rare case of cavernous hemangioma in an area that received a low dose of irradiation and was distant from the primary tumor. Because patients undergoing radiosurgery face the possibility, although small, that such neoplasms may occur, they should be followed for many years.

scholarly journals Clinical impact of magnetic resonance imaging distortions on gamma knife radiosurgery

2021 ◽  
Author(s):  
Sinead Jacobson ◽  
Catherine Jones ◽  
Ryan Lusk ◽  
Mike Jenkins ◽  
Crispen Chamunyonga ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Clinical Impact ◽  
Resonance Imaging

scholarly journals Multigrid Nonlocal Gaussian Mixture Model for Segmentation of Brain Tissues in Magnetic Resonance Images

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Yunjie Chen ◽  
Tianming Zhan ◽  
Ji Zhang ◽  
Hongyuan Wang
Keyword(s):  
Magnetic Resonance ◽  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Gaussian Mixture ◽  
Magnetic Resonance Images ◽  
Intensity Inhomogeneity ◽  
Mr Images ◽  
Proposed Model ◽  
Brain Mr Images ◽  
The Impact

We propose a novel segmentation method based on regional and nonlocal information to overcome the impact of image intensity inhomogeneities and noise in human brain magnetic resonance images. With the consideration of the spatial distribution of different tissues in brain images, our method does not need preestimation or precorrection procedures for intensity inhomogeneities and noise. A nonlocal information based Gaussian mixture model (NGMM) is proposed to reduce the effect of noise. To reduce the effect of intensity inhomogeneity, the multigrid nonlocal Gaussian mixture model (MNGMM) is proposed to segment brain MR images in each nonoverlapping multigrid generated by using a new multigrid generation method. Therefore the proposed model can simultaneously overcome the impact of noise and intensity inhomogeneity and automatically classify 2D and 3D MR data into tissues of white matter, gray matter, and cerebral spinal fluid. To maintain the statistical reliability and spatial continuity of the segmentation, a fusion strategy is adopted to integrate the clustering results from different grid. The experiments on synthetic and clinical brain MR images demonstrate the superior performance of the proposed model comparing with several state-of-the-art algorithms.

Gamma knife radiosurgery as a lesioning technique in movement disorder surgery

1997 ◽  
Vol 2 (3) ◽  
pp. E13 ◽  
Author(s):  
Ronald F. Young ◽  
Anne Shumway-Cook ◽  
Sandra S. Vermeulen ◽  
Peter Grimm ◽  
John Blasko ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Movement Disorder ◽  
Gamma Knife ◽  
Movement Disorders ◽  
Rating Scale ◽  
Gamma Knife Radiosurgery ◽  
Magnetic Resonance Images ◽  
Maximum Deviation

Fifty-five patients underwent radiosurgical placement of lesions either in the thalamus (27 patients) or globus pallidus (28 patients) for treatment of movement disorders. Patients were evaluated pre- and postoperatively by a team of observers skilled in the assessment of gait and movement disorders who were blinded to the procedure performed. They were not associated with the surgical team and concomitantly and blindly also assessed a group of 11 control patients with Parkinson's disease who did not undergo any surgical procedures. All stereotactic lesions were made with the Leksell gamma unit using the 4-mm secondary collimator helmet and a single isocenter with dose maximums from 120 to 160 Gy. Clinical follow-up evaluation indicated that 88% of patients who underwent thalamotomy became tremor free or nearly tremor free. Statistically significant improvements in performance were noted in the independent assessments of Unified Parkinson's Disease Rating Scale (UPDRS) scores in the patients undergoing thalamotomy. Eighty-five and seven-tenths percent of patients undergoing pallidotomy who had exhibited levodopa-induced dyskinesias had total or near-total relief of that symptom. Clinical assessment indicated improvement of bradykinesia and rigidity in 64.3% of patients who underwent pallidotomy. Independent blinded assessments did not reveal statistically significant improvements in Hoehn and Yahr scores or UPDRS scores. On the other hand, 64.7% of patients showed improvements in subscores of the UPDRS, including activities of daily living (58%), total contralateral score (58%), and contralateral motor scores (47%). Ipsilateral total UPDRS and ipsilateral motor scores were both improved in 59% of patients. One (1.8%) of 55 patients experienced a homonymous hemianopsia 9 months after pallidotomy due to an unexpectedly large lesion. No other complications of any kind were seen. Follow-up neuroimaging confirmed correct lesion location in all patients, with a mean maximum deviation from the planned target of 1 mm in the vertical axis. Measurements of lesions at regular interals on postoperative magnetic resonance images demonstrated considerable variability in lesion volumes. The safety and efficacy of functional lesions made with the gamma knife appear to be similar to those made with the assistance of electrophysiological guidance with open functional stereotactic procedures. Functional lesions may be made safely and accurately using gamma knife radiosurgical techniques. The efficacy is equivalent to that reported for open techniques that use radiofrequency lesioning methods with electrophysiological guidance. Complications are very infrequent with the radiosurgical method. The use of functional radiosurgical lesioning to treat movement disorders is particularly attractive in older patients and those with major systemic diseases or coagulopathies; its use in the general movement disorder population seems reasonable as well.

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