Histopathological Changes in Cerebral Arteriovenous Malformations following Stereotacitc Irradiation with the Gamma Knife

Abstract BACKGROUND Large cerebral arteriovenous malformations (AVM) pose a management dilemma because of the limited success of any single treatment modality by itself. Surgery alone is associated with significant morbidity and mortality. Similarly, embolization alone has limited efficacy. Volume-staged gamma knife radiosurgery (VSGR) has been developed for the treatment of large AVMs, to increase the efficacy and improve safety of treatment of these lesions. The aim of the study was to assess the efficacy and safety of VSGR technique for the treatment of large cerebral AVMs. METHODS The study included patients treated by VSGR between May 2009 and July 2015. All cases had large AVMs (>10 cc). These were 29 patients. RESULTS Twenty-four patients completed radiographic follow up with 15 obliteration cases (62.5%). There was a total of 56 sessions performed. The mean AVM volume was 16 cc (10.1–29.3 cc). The mean prescription dose was 18 Gy (14–22 Gy). The mean follow up duration was 43 months (21–73 months). One patient died during follow up from unrelated cause. Two cases suffered haemorrhage during follow up. Symptomatic edema developed in 5 (17%) patients. The factors affecting obliteration were smaller total volume, higher dose/stage, non-deep location, compact AVM, AVM score less than 3, >18 Gy dose and <15 cc total volume. The factors affecting symptomatic edema were smaller total volume and shorter time between first and last sessions (p 0.012). T2 image changes were affected by SM grade 3 or more (p 0.013) and AVM score 3 or more (p 0.014). CONCLUSION VSGR provides an effective and safe treatment option for large cerebral AVMs. Smaller AVM volume is associated with higher obliteration rate.

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Gamma Knife surgery for incidental cerebral arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/2014.7.jns131397 ◽

2014 ◽

Vol 121 (5) ◽

pp. 1015-1021 ◽

Cited By ~ 42

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.

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Gamma Knife Radiosurgery for Cerebral Arteriovenous Malformations

Surgery for Cerebral Stroke ◽

10.2335/scs1987.27.4_241 ◽

1999 ◽

Vol 27 (4) ◽

pp. 241-247 ◽

Cited By ~ 1

Author(s):

Masaaki YAMAMOTO ◽

Takayuki TANAKA ◽

Nagatoshi BOKU ◽

Seiji FUKUOKA ◽

Hiromichi HOSODA ◽

...

Keyword(s):

Gamma Knife ◽

Arteriovenous Malformations ◽

Gamma Knife Radiosurgery ◽

Cerebral Arteriovenous Malformations

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Repeat Gamma Knife Surgery for Incompletely Obliterated Cerebral Arteriovenous Malformations

Neurosurgery ◽

10.1227/01.neu.0000370204.68711.ac ◽

2010 ◽

Vol 67 (1) ◽

pp. 55-64 ◽

Cited By ~ 24

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.

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Combined Embolization and Gamma Knife Radiosurgery for Cerebral Arteriovenous Malformations

Acta Radiologica ◽

10.1177/028418519303400614 ◽

1993 ◽

Vol 34 (6) ◽

pp. 600-606 ◽

Cited By ~ 28

Author(s):

W. Y. Guo ◽

G. Wikholm ◽

B. Karlsson ◽

C. Lindquist ◽

P. Svendsen ◽

...

Keyword(s):

Gamma Knife ◽

Arteriovenous Malformations ◽

Combined Treatment ◽

Time Lag ◽

Gamma Knife Radiosurgery ◽

Cerebral Arteriovenous Malformations ◽

Neurologic Deficits ◽

Feeding Vessels ◽

Grade Iii

In a study of 46 patients with cerebral arteriovenous malformations (AVMs) the value of combining embolization and gamma knife radiosurgery was assessed. In 35 patients with large grade III to V AVMs (Spetzler-Martin system) staged combined treatment was planned. In 11 patients, radiosurgery complemented embolization for a residual AVM. The number of embolization sessions ranged from 1 to 7 (median 2). Twenty-six patients needed multiple embolization sessions. In 28 patients the grade of AVMs decreased as a result of embolization. In 16 patients collateral feeding vessels developed after embolization which made delineation of the residual nidus difficult. The time lag between the last embolization and radiosurgery ranged from 1 to 24 months (median 4). Nineteen of 35 large grade III to V AVMs were possible to treat by radiosurgery following embolization. In the 46 patients complications occurred in 9 from embolization and in 2 from radiosurgery. Two patients had transient and 9 had permanent neurologic deficits. It is concluded that embolization facilitates radiosurgery for some large AVMs and therefore this combined treatment has a role in the management of AVMs.

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

Journal of Neurosurgery ◽

10.3171/jns/2008/109/8/0191 ◽

2008 ◽

Vol 109 (2) ◽

pp. 191-198 ◽

Cited By ~ 25

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.

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