scholarly journals Low Dose Gamma Knife Surgery for Small Cerebral Arteriovenous Malformations

2005 ◽  
Vol 33 (5) ◽  
pp. 352-356 ◽  
Author(s):  
Toru SERIZAWA ◽  
Yoshinori HIGUCHI ◽  
Junichi ONO ◽  
Osamu NAGANO ◽  
Naokatsu SAEKI
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Low Dose ◽  
Gamma Knife Surgery ◽  
Cerebral Arteriovenous Malformations

scholarly journals Gamma Knife surgery for incidental cerebral arteriovenous malformations

2014 ◽  
Vol 121 (5) ◽  
pp. 1015-1021 ◽  
Author(s):  
Chun-Po Yen ◽  
Dale Ding ◽  
Ching-Hsiao Cheng ◽  
Robert M. Starke ◽  
Mark Shaffrey ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Latency Period ◽  
Invasive Procedure ◽  
Gamma Knife Surgery ◽  
Neurological Deficits ◽  
Cerebral Arteriovenous Malformations ◽  
Long Term Follow Up

Object A relatively benign natural course of unruptured cerebral arteriovenous malformations (AVMs) has recently been recognized, and the decision to treat incidentally found AVMs has been questioned. This study aims to evaluate the long-term imaging and clinical outcomes of patients with asymptomatic, incidentally discovered AVMs treated with Gamma Knife surgery (GKS). Methods Thirty-one patients, each with an incidentally diagnosed AVM, underwent GKS between 1989 and 2009. The nidus volumes ranged from 0.3 to 11.1 cm3 (median 3.2 cm3). A margin dose between 15 and 26 Gy (median 20 Gy) was used to treat the AVMs. Four patients underwent repeat GKS for still-patent AVM residuals after the initial GKS procedure. Clinical follow-up ranged from 24 to 196 months, with a mean of 78 months (median 51 months) after the initial GKS. Results Following GKS, 19 patients (61.3%) had a total AVM obliteration on angiography. In 7 patients (22.6%), no flow voids were observed on MRI but angiographic confirmation was not available. In 5 patients (16.1%), the AVMs remained patent. A small nidus volume was significantly associated with increased AVM obliteration rate. Thirteen patients (41.9%) developed radiation-induced imaging changes: 11 were asymptomatic (35.5%), 1 had only headache (3.2%), and 1 developed seizure and neurological deficits (3.2%). Two patients each had 1 hemorrhage during the latency period (116.5 risk years), yielding an annual hemorrhage rate of 1.7% before AVM obliteration. Conclusions The decision to treat asymptomatic AVMs, and if so, which treatment approach to use, remain the subject of debate. GKS as a minimally invasive procedure appears to achieve a reasonable outcome with low procedure-related morbidity. In those patients with incidental AVMs, the benefits as well as the risks of radiosurgical intervention will only be fully defined with long-term follow-up.

scholarly journals Repeat Gamma Knife Surgery for Incompletely Obliterated Cerebral Arteriovenous Malformations

Neurosurgery ◽  
2010 ◽  
Vol 67 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Chun-Po Yen ◽  
Surbhi Jain ◽  
Iftikhar-ul Haq ◽  
Jay Jagannathan ◽  
David Schlesinger ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Surgery ◽  
Neurological Deficits ◽  
Resonance Imaging ◽  
Cerebral Arteriovenous Malformations ◽  
Radiation Induced ◽  
Induced Changes

Abstract OBJECTIVE The causes of failure after an initial Gamma procedure were studied, along with imaging and clinical outcomes, in a series of 140 patients with cerebral arteriovenous malformations (AVMs) treated with repeat Gamma Knife surgery (GKS). METHODS Causes of initial treatment failure included inaccurate nidus definition in 14 patients, failure to fill part of the nidus as a result of hemodynamic factors in 16, recanalization of embolized AVM compartments in 6, and suboptimal dose (< 20 Gy) in 23. Nineteen patients had repeat GKS for subtotal obliteration of AVMs. In 62 patients, the AVM failed to obliterate despite correct target definition and adequate dose. At the time of retreatment, the nidus volume ranged from 0.1 to 6.9 cm3 (mean, 1.4 cm3), and the mean prescription dose was 20.3 Gy. RESULTS Repeat GKS yielded a total angiographic obliteration in 77 patients (55%) and subtotal obliteration in 9 (6.4%). In 38 patients (27.1%), the AVMs remained patent, and in 16 patients (11.4%), no flow voids were observed on magnetic resonance imaging. Clinically, 126 patients improved or remained stable, and 14 experienced deterioration (8 resulting from a rebleed, 2 caused by persistent arteriovenous shunting, and 4 related to radiation-induced changes). CONCLUSION By using repeat GKS, we achieved a 55% angiographic cure rate. Although radiation-induced changes as visualized on magnetic resonance imaging occurred in 48 patients (39%), only 4 patients (3.6%) developed permanent neurological deficits. These findings may be useful in deciding the management of AVMs in whom total obliteration after initial GKS was not achieved.

Clinical and neuroimaging outcome of cerebral arteriovenous malformations after Gamma Knife surgery: analysis of the radiation injury rate depending on the arteriovenous malformation volume

2008 ◽  
Vol 109 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Jung Ho Han ◽  
Dong Gyu Kim ◽  
Hyun-Tai Chung ◽  
Chul-Kee Park ◽  
Sun Ha Paek ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Radiation Injury ◽  
Injury Rate ◽  
Gamma Knife Surgery ◽  
Cerebral Arteriovenous Malformations ◽  
Bleeding Rate ◽  
Reduced Dose ◽  
The Mean

Object In this paper the authors analyzed the clinical and neuroimaging outcomes of patients with cerebral arteriovenous malformations (AVMs) after Gamma Knife surgery (GKS), focusing on the analysis of the radiation injury rate depending on the AVM volume. Methods Between 1997 and 2004, 277 consecutive patients with cerebral AVMs were treated with GKS. Of these patients, 218 were followed up for ≥ 2 years. The mean age was 31 ± 15 years, the median AVM volume was 3.4 cm3 (range 0.17–35.2 cm3), the median marginal dose was 18.0 Gy (range 10.0–25.0 Gy), and the mean follow-up duration was 44 ± 20 months. The authors reduced the prescription dose by various amounts, depending on the AVM volume and location as prescribed in the classic guideline to avoid irreversible radiation injuries. Results The angiographic obliteration rate was 66.4% overall, and it was 81.7, 53.1, and 12.5% for small, medium, and large AVMs, respectively. The overall annual bleeding rate was 1.9%. The annual bleeding rate was 0.44 and 4.64% for small and large AVMs, respectively. Approximately 20% of the patients showed severe postradiosurgery imaging (PRI) changes. The rate of PRI change was 11.4, 33.3, and 9.5% for small, medium, and large AVM volume groups, respectively, and a permanent radiation injury developed in 5.1% of patients. Conclusions By using the reduced dose from what is usually prescribed, the authors were able to obtain outcomes in small AVMs that were comparable to the outcomes described in previous reports. However, medium AVMs appear to still be at risk for adverse radiation effects. Last, in large AVMs, the authors were able to attain a tolerable rate of radiation injury; however, the clinical outcomes were quite disappointing following administration of a reduced dose of GKS for large AVMs.

Gamma Knife surgery for basal ganglia and thalamic arteriovenous malformations

2012 ◽  
Vol 116 (4) ◽  
pp. 899-908 ◽  
Author(s):  
Ching-Hsiao Cheng ◽  
R. Webster Crowley ◽  
Chun-Po Yen ◽  
David Schlesinger ◽  
Mark E. Shaffrey ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Mr Imaging ◽  
Gamma Knife ◽  
Treatment Option ◽  
Arteriovenous Malformations ◽  
Gamma Knife Surgery ◽  
Neurological Deficits ◽  
Cerebral Arteriovenous Malformations ◽  
History Of ◽  
The Mean

Object Gamma Knife surgery (GKS) has emerged as the treatment of choice for small- to medium-sized cerebral arteriovenous malformations (AVMs) in deep locations. The present study aims to investigate the outcomes of GKS for AVMs in the basal ganglia and thalamus. Methods Between 1989 and 2007, 85 patients with AVMs in the basal ganglia and 97 in the thalamus underwent GKS and were followed up for more than 2 years. The nidus volumes ranged from 0.1 to 29.4 cm3 (mean 3.4 cm3). The mean margin dose at the initial GKS was 21.3 Gy (range 10–28 Gy). Thirty-six patients underwent repeat GKS for residual AVMs at a median 4 years after initial GKS. The mean margin dose at repeat GKS was 21.1 Gy (range 7.5–27 Gy). Results Following a single GKS, total obliteration of the nidus was confirmed on angiograms in 91 patients (50%). In 12 patients (6.6%) a subtotal obliteration was achieved. No flow voids were observed on MR imaging in 14 patients (7.7%). Following single or repeat GKS, total obliteration was angiographically confirmed in 106 patients (58.2%) and subtotal obliteration in 8 patients (4.4%). No flow voids on MR imaging were observed in 18 patients (9.9%). The overall obliteration rates following one or multiple GKSs based on MR imaging or angiography was 68%. A small nidus volume, high margin dose, low number of isocenters, and no history of embolization were significantly associated with an increased rate of obliteration. Twenty-one patients experienced 25 episodes of hemorrhage in 850 risk-years following GKS, yielding an annual hemorrhage rate of 2.9%. Four patients died in this series: 2 due to complications of hemorrhage and 2 due to unrelated diseases. Permanent neurological deficits caused by radiation were noted in 9 patients (4.9%). Conclusions Gamma Knife surgery offers a reasonable chance of obliterating basal ganglia and thalamic AVMs and does so with a low risk of complications. It is an optimal treatment option in patients for whom the anticipated risk of microsurgery is too high.

Radiation-induced imaging changes following Gamma Knife surgery for cerebral arteriovenous malformations

2013 ◽  
Vol 118 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Chun-Po Yen ◽  
Julie A. Matsumoto ◽  
Max Wintermark ◽  
Lucia Schwyzer ◽  
Avery J. Evans ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Clinical Manifestations ◽  
Mass Effect ◽  
Gamma Knife Surgery ◽  
Cerebral Arteriovenous Malformations ◽  
Prior Surgery ◽  
Radiation Induced ◽  
Grade Ii ◽  
Grade Iii

Object The objective of this study was to evaluate the incidence, severity, clinical manifestations, and risk factors of radiation-induced imaging changes (RIICs) following Gamma Knife surgery (GKS) for cerebral arteriovenous malformations (AVMs). Methods A total of 1426 GKS procedures performed for AVMs with imaging follow-up available were analyzed. Radiation-induced imaging changes were defined as newly developed increased T2 signal surrounding the treated AVM nidi. A grading system was developed to categorize the severity of RIICs. Grade I RIICs were mild imaging changes imposing no mass effect on the surrounding brain. Grade II RIICs were moderate changes causing effacement of the sulci or compression of the ventricles. Grade III RIICs were severe changes causing midline shift of the brain. Univariate and multivariate logistic regression analyses were applied to test factors potentially affecting the occurrence, severity, and associated symptoms of RIICs. Results A total of 482 nidi (33.8%) developed RIICs following GKS, with 281 classified as Grade I, 164 as Grade II, and 37 as Grade III. The median duration from GKS to the development of RIICs was 13 months (range 2–124 months). The imaging changes disappeared completely within 2–128 months (median 22 months) following the development of RIICs. The RIICs were symptomatic in 122 patients, yielding an overall incidence of symptomatic RIICs of 8.6%. Twenty-six patients (1.8%) with RIICs had permanent deficits. A negative history of prior surgery, no prior hemorrhage, large nidus, and a single draining vein were associated with a higher risk of RIICs. Conclusions Radiation-induced imaging changes are the most common adverse effects following GKS. Fortunately, few of the RIICs are symptomatic and most of the symptoms are reversible. Patients with a relatively healthy brain and nidi that are large, or with a single draining vein, are more likely to develop RIICs.

Outcome after hemorrhage following Gamma Knife surgery for cerebral arteriovenous malformations

2009 ◽  
Vol 110 (5) ◽  
pp. 1003-1009 ◽  
Author(s):  
Manish Kumar Kasliwal ◽  
Shashank Sharad Kale ◽  
Aditya Gupta ◽  
Narayanam Anantha Sai Kiran ◽  
Manish Singh Sharma ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Venous Drainage ◽  
Venous Hypertension ◽  
Gamma Knife Surgery ◽  
New Delhi ◽  
Cerebral Arteriovenous Malformations ◽  
Complete Obliteration ◽  
Cerebral Avms ◽  
Risk Of Hemorrhage

Object Although the effects of Gamma Knife surgery (GKS) on the risk of hemorrhage are poorly understood, a certain subset of patients does suffer bleeding after GKS. This study was undertaken to analyze the outcome of patients sustaining hemorrhage after GKS; it is the most feared complication of radiosurgical management of cerebral arteriovenous malformations (AVMs). Methods Between May 1997 and June 2006, 494 cerebral AVMs in 489 patients were treated using a Leksell Gamma Knife Model B, and follow-up evaluations were conducted until June 2007 at the All India Institute of Medical Sciences in New Delhi. Fourteen patients who sustained a hemorrhage after GKS formed the study group. In most of these patients conservative management was chosen. Results The mortality rate was 0% and there was a 7% risk of sustaining a severe deficit following rebleeding after GKS. None of the patients sustained rebleeding after complete obliteration. Patients with Spetzler-Martin Grade III or less had increased chances of hemorrhage after GKS (p < 0.002). The presence of deep venous drainage, aneurysm, venous hypertension, or periventricular location on angiography was common in patients with hemorrhage after GKS. Conclusions The risk of hemorrhage that remains following GKS for cerebral AVMs is highest in the 1st year after treatment. The present study showed a relatively good outcome even in cases with hemorrhage following GKS, with no deaths and minimal morbidity, further substantiating the safety and efficacy of the procedure.

Sign in / Sign up

Export Citation Format

Share Document