Systematic Review and Meta-Analysis of the Dose-Response and Risk Factors for Obliteration of Arteriovenous Malformations Following Radiosurgery: An Update Based on the Last 20 Years of Published Clinical Evidence

Abstract

BACKGROUND Intracranial arteriovenous malformation (AVM) is a congenital lesion that can potentially lead to devastating consequences if not treated. Many institutional cohort studies have reported on the outcomes after radiosurgery and factors associated with successful obliteration in the last few decades. OBJECTIVE To quantitatively assess the dose-response relationship and risk factors associated with AVM obliteration using a systematic review and meta-analysis approach. METHODS Data were extracted from reports published within the last 20 yr. The dose-response fit for obliteration as a function of marginal dose was performed using inverse-variance weighting. Risk factors for AVM obliteration were assessed by combining odds ratios from individual studies using inverse-variance weighting. RESULTS The logistic model fit showed a clear association between higher marginal dose and higher rates of obliteration. There appeared to be a difference in the steepness in dose-response when comparing studies with patients treated using Gamma Knife radiosurgery (Elekta), compared to linear accelerators (LINACs), and when stratifying studies based on the size of treated AVMs. In the risk-factor analysis, AVM obliteration rate decreases with larger AVM volume or AVM diameter, higher AVM score or Spetzler-Martin (SM) grade, and prior embolization, and increases with compact AVM nidus. No statistically significant associations were found between obliteration rate and age, sex, prior hemorrhage, prior aneurysm, and location eloquence. CONCLUSION A marginal dose above 18 Gy was generally associated with AVM obliteration rates greater than 60%, although lesion size, AVM score, SM grade, prior embolization, and nidus compactness all have significant impact on AVM obliteration rate.

Treatment of Intracranial Tumors With Stereotactic Radiosurgery: Short-Term Results From Cuba

“…SRS is currently used to treat patients with a variety of processes including cerebral vascular malformations (arteriovenous malformations or AVMs [ 15 ] and cavernous angiomas [ 16 ]), benign tumors (meningiomas [ 17 - 18 ], vestibular schwannoma [ 19 ], pituitary adenoma [ 20 - 21 ], glomus jugulare tumors [ 22 ], low-grade glioma [ 23 ]), and malignant tumors (metastasis [ 24 ], chordoma [ 25 ], high-grade glioma [ 26 ]). Other less common indications are Cushing's disease [ 27 - 28 ], epilepsy [ 29 ], trigeminal neuralgia [ 30 ], and movement disorders [ 31 ].…”

Gross Total Resection of a Ruptured Micro-arteriovenous Malformation within the Cerebellar Peduncle: A Case Report and Qualitative Review of the Literature

“…13 A large meta-analysis of radiosurgery for AVMs found that obliteration rates are most favorable for smaller AVMs (even at lower doses) and compact nidi in addition to several other factors. 14 The risk of repeat hemorrhage during the time to obliteration following treatment must be considered in the management of micro-AVMs. Friedman et al reviewed outcomes in 201 patients with AVMs treated with radiosurgery and discovered that the annual risk of postoperative hemorrhage is 3.7% within 5 years.…”

A Ruptured Spetzler and Martin Grade V Arteriovenous Malformation in a Child Treated With Radiotherapy Followed by Embolization: A Case Report and Literature Review

“…For VS-SRS, a gamma knife is basically used, and the mean marginal dose varies from 15 to 20 Gy, and the number of stages of irradiations is often reported to be two to four stages [ 14 , 15 ]. For dose staged SRS, a linear accelerator (LINAC) is used, and the mean total dose varies from 26 to 50 Gy, and the number of stages of irradiation varies from two to 12 stages [ 16 , 17 ]. The mean complete occlusion rate was 32.3% for DS-SRS and 41.2% for VS-SRS [ 15 ].…”