Gamma knife surgery with and without embolization for cerebral arteriovenous malformations: A systematic review and meta-analysis

doi:10.1016/j.jocn.2018.07.008

Journal of Clinical Neuroscience

Volume 56, October 2018, Pages 67-73

https://doi.org/10.1016/j.jocn.2018.07.008 Get rights and content

Highlights

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Embolization prior to GKS significantly may decrease the AVM obliteration rate.
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Embolization prior to GKS didn’t reduce the risk of hemorrhage compared to CKS alone in treating AVM.
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Embolization prior to GKS didn’t reduce the risk of permanent neurological deficits compared to CKS alone in treating AVM.

Abstract

The benefit and risk of gamma knife surgery (GKS) in the treatment of residual cerebral arteriovenous malformations (AVMs) after endovascular embolization remain controversial. The aim of this meta-analysis was to assess current evidence regarding the efficiency and safety of GKS for AVMs with and without prior embolization. To compare GKS in patients with and without embolization, the authors conducted a meta-analysis of studies by searching the literature via PubMed and EMBASE databases for the period between January 2006 and December 2017. Six retrospective studies were finally identified. Outcomes were the rate of AVM obliteration on a 3-year follow-up angiogram, hemorrhage at 3 years after GKS and permanent neurological deficits. Six studies eligible for analysis included 2069 patients: 637 had undergone embolization followed by GKS, and 1432 had undergone GKS alone. The obliteration rate was significantly lower in patients who had undergone embolization followed by GKS than in those who had undergone GKS alone (49.5% vs 70.4%, OR 2.29, 95% CI 1.55–3.38, p < 0.00001). Subgroup analysis also indicated high obliteration rates in ‘similar mean nidus volume’, ‘high quality’ and ‘sample size over 100 patients’ subgroups. However, the rates of rehemorrhage (8.9% vs 4.2%, OR 0.59, 95% CI 0.23–1.57, p = 0.29) and permanent neurological deficits rate (3.6% vs 4.6%, OR 0.51, 95% CI 0.57–3.12, p = 0.51) were not significantly different between the two groups and subgroups. Embolization prior to GKS significantly decreases the AVM obliteration rate and didn’t reduce the risk of hemorrhage and permanent neurological deficits. Further evaluation by well-designed prospective or randomized cohort studies is highly needed.

Section snippets

Search strategy

Three reviewers (Deyuan Zhu, Zhe Li and Yongxin Zhang) performed a comprehensive review of articles in the literature published between January 2006 and December 2017. An electronic search of PubMed and EMBASE databases was conducted. This search was supplemented by hand searching the six journals in which most studies were published (Neurosurgery, Journal of Neurosurgery, American Journal of Neuroradiology, Surgical Neurology, Journal of NeuroInterventional Surgery and Stroke) and the

Study selection

Fig. 1 shows a flow diagram according to the Quality of Reporting of Meta-analyses statement. Of all the included studies, none was a randomized controlled trial, 6 (100%) were retrospective studies. The studies had been performed in the United States (5) and Japan (1). A total of 729 articles were retrieved from the PubMed and EMBASE databases. After removing duplicated articles, we screened 622 titles and abstracts. No new studies were found in the six journals or the reference lists. As a

Discussion

AVMs continue to be one of the most challenging cerebrovascular diseases for their complex physiology and angioarchitecture [8]. Embolization prior to GKS is minimally invasive approach for large or morphologically complex AVMs that are associated with high surgical risk and are not amenable to successful treatment with either embolization or GKS alone [8]. Our meta-analysis systematically summarized the available evidence on outcomes in AVM patients who underwent embolization prior to GKS or

Conclusion

The results of our meta-analysis showed that embolization prior to GKS significantly decreases the obliteration rate However, there was no significant difference in the risk of hemorrhage and permanent neurological deficits caused by radiation-induced changes between embolization prior to GKS and GKS alone. The adverse impact of embolization AVM GKS outcomes may be overestimated by prior studies. Further validation through well-designed prospective or randomized cohort studies is highly needed.

Sources of funding

The study was supported by the Scientific Research Projects of Science and Technology Committee of Shanghai, China. (No. 13411950301).

Conflict of interest

The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Guarantor: Qinghai Huang, M.D. and Jianmin Liu, M.D.

Informed consent and ethical approval

This study is a meta-analysis and no human participant procedure was involved. Informed consent and ethical approval may not be essential for this study.

References (25)

M. Izawa et al.
Iseki H, Hori T, Takakura K. Combined management of intracranial arteriovenous malformations with embolization and gamma knife radiosurgery: comparative evaluation of the long-term results
Surg Neurol
(2009)
T.J. Buell et al.
Embolization-induced angiogenesis in cerebral arteriovenous malformations
J Clin Neurosci
(2014)
U. Sure et al.
Treatment-induced neoangiogenesis in cerebral arteriovenous malformations
Clin Neurol Neurosurg
(2001)
M.K. Baskaya et al.
Cerebral arteriovenous malformations
Clin Neurosurg
(2006)
R.D. Brown et al.
The natural history of unruptured intracranial arteriovenous malformations
J Neurosurg
(1988)
R.D. Brown et al.
Incidence and prevalence of intracranial vascular malformations in Olmsted County, Minnesota, 1965 to 1992
Neurology
(1996)
H.K. Inoue
Long-term results of Gamma Knife surgery for arteriovenous malformations: 10- to 15-year follow up in patients treated with lower doses
J Neurosurg
(2006)
K. Maruyama et al.
Radiosurgery to reduce the risk of first hemorrhage from brain arteriovenous malformations
Neurosurgery
(2007)
D.R. Buis et al.
Gamma knife surgery and arteriovenous malformations
J Neurosurg Pediatr
(2008)
S.L. Blackburn et al.
Combined endovascular embolization and stereotactic radiosurgery in the treatment of large arteriovenous malformations: clinical article
J Neurosurg
(2011)

E.K. Oermann et al.

Effect of prior embolization on cerebral arteriovenous malformation radiosurgery outcomes: a case-control study

Neurosurgery

(2015)

R.M. Starke et al.

CP and others. Stereotactic radiosurgery for cerebral arteriovenous malformations: evaluation of long-term outcomes in a multicenter cohort

J Neurosurg

(2016)

Cited by (12)

A Machine Learning Model Predicts the Outcome of SRS for Residual Arteriovenous Malformations after Partial Embolization: A Real-World Clinical Obstacle
2022, World Neurosurgery
Citation Excerpt :
The addition of EMB prior to SRS is a commonly used method to reduce the volume of bAVM and to reduce the risk of hemorrhage. Some studies have demonstrated that partial embolization prior to SRS may reduce the rate of bAVM obliteration2,3; however, in certain circumstances, this method is still considered direct and effective, because EMB can reduce the volume of bAVMs and allowing for a more targeted approach at the nidus during SRS, which ultimately increases the obliteration rate.4-7 In real-world clinical practice, the use of EMB prior to SRS is circumstantial8,9; some patients with a partially embolized bAVM may respond well to SRS, whereas others may not.4,10-12
To propose a machine learning (ML) model predicting the favorable outcome of stereotactic radiosurgery (SRS) for residual brain arteriovenous malformation (bAVM) after partial embolization.
One hundred and thirty bAVM patients who underwent partial embolization followed by SRS were reviewed retrospectively. Patients were split at random split into training datasets (n = 100) and testing datasets (n = 30). Radiomics and dosimetric features were extracted from pre-SRS treatment images. Feature selection was performed to select appropriate radiomics and dosimetric features. Three ML algorithms were applied to construct models using selected features respectively. A total of 9 models were trained to predict favorable outcomes (obliteration without complication) of bAVMs. The efficacy of these models was evaluated on the testing dataset using mean accuracy (ACC) and area under the receiver operating characteristic curve (AUC).
The obliteration rate of this cohort was 70.77% (92 of 130) with a mean follow-up of 43.8 months (range, 12–108 months). Favorable outcomes were achieved in 89 patients (68.46%). Four radiomics features and 7 dosimetric features were selected for ML model construction. The dosimetric support vector machines (SVM) model showed the best performance on the training dataset, with an ACC of 0.74 and AUC of 0.78. The dosimetric SVM model also showed the best performance on the testing dataset, with an ACC of 0.83 and AUC of 0.77.
Dosimetric features are good predictors of prognosis for patients with partially embolized bAVM followed by SRS therapy. The use of ML models is an innovative method for predicting favorable outcomes of partially embolized bAVM followed by SRS therapy.
The impact of embolization on radiosurgery obliteration rates for brain arteriovenous malformations: a systematic review and meta‐analysis
2023, Neurosurgical Review
The impact of opioid administration for post gamma knife radiosurgery frame removal: a prospective quality-improvement study
2023, Journal of Neuro-Oncology
Long-term outcome of a tailored embolization strategy with Gamma Knife radiosurgery for high-grade brain arteriovenous malformations: a single-center experience
2023, Journal of Neurosurgery
Comparison of Single-Session, Neoadjuvant, and Adjuvant Embolization Gamma Knife Radiosurgery for Arteriovenous Malformation
2023, Neurosurgery
Endovascular treatment of dural arteriovenous fistulas involving the vein of Galen: A single-center cohort and meta-Analysis
2023, Journal of NeuroInterventional Surgery

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¹: Contributed equally to this work.

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Clinical studyGamma knife surgery with and without embolization for cerebral arteriovenous malformations: A systematic review and meta-analysis

Highlights

Abstract

Section snippets

Search strategy

Study selection

Discussion

Conclusion

Sources of funding

Conflict of interest

Informed consent and ethical approval

Surg Neurol

J Clin Neurosci

Clin Neurol Neurosurg

Cerebral arteriovenous malformations

Clin Neurosurg

The natural history of unruptured intracranial arteriovenous malformations

J Neurosurg

Incidence and prevalence of intracranial vascular malformations in Olmsted County, Minnesota, 1965 to 1992

Neurology

Long-term results of Gamma Knife surgery for arteriovenous malformations: 10- to 15-year follow up in patients treated with lower doses

J Neurosurg

Radiosurgery to reduce the risk of first hemorrhage from brain arteriovenous malformations

Neurosurgery

Gamma knife surgery and arteriovenous malformations

J Neurosurg Pediatr

Combined endovascular embolization and stereotactic radiosurgery in the treatment of large arteriovenous malformations: clinical article

J Neurosurg

Effect of prior embolization on cerebral arteriovenous malformation radiosurgery outcomes: a case-control study

Neurosurgery

CP and others. Stereotactic radiosurgery for cerebral arteriovenous malformations: evaluation of long-term outcomes in a multicenter cohort

J Neurosurg

Clinical study
Gamma knife surgery with and without embolization for cerebral arteriovenous malformations: A systematic review and meta-analysis