Radiosurgery for ruptured intracranial arteriovenous malformations

Object Ruptured intracranial arteriovenous malformations (AVMs) are at a significantly greater risk for future hemorrhage than unruptured lesions, thereby necessitating treatment in the majority of cases. In a retrospective, single-center study, the authors describe the outcomes after radiosurgery in a large cohort of patients with ruptured AVMs. Methods From an institutional review board–approved, prospectively collected AVM radiosurgery database, the authors identified all patients with a history of AVM rupture. They analyzed obliteration rates in all patients in whom radiological follow-up data were available (n = 639). However, to account for the latency period associated with radiosurgery, only those patients with more than 2 years of radiological follow-up and those with earlier AMV obliteration were included in the analysis of prognostic factors related to obliteration and complications. This resulted in a cohort of 565 patients with ruptured AVMs for whom data were analyzed; these patients had a median radiological follow-up of 57 months and a median age of 29 years. Twenty-one percent of the patients underwent preradiosurgery embolization. The median volume and prescription dose were 2.1 cm3 and 22 Gy, respectively. The Spetzler-Martin grade was III or higher in 56% of patients, the median radiosurgery-based AVM score was 1.08, and the Virginia Radiosurgery AVM Scale (RAS) score was 3 to 4 points in 44%. Survival and regression analyses were performed to determine obliteration rates over time and predictors of obliteration and complications. Results In the overall population of 639 patients with ruptured AVMs, the obliteration rate was 11.1% based on MRI only (71 of 639 patients), 56.0% based on angiography (358 of 639), and 67.1% based on combined modalities (429 of 639 patients). In the cohort of patients with 2 years of follow-up or an earlier AVM obliteration, the cumulative obliteration rate was 76% and the actuarial obliteration rates were 41% and 64% at 3 and 5 years, respectively. Multivariate analysis identified the absence of preradiosurgery embolization (p < 0.001), increased prescription dose (p = 0.001), the presence of a single draining vein (p = 0.046), no postradiosurgery-related hemorrhage (p = 0.007), and lower Virginia RAS score (p = 0.020) as independent predictors of obliteration. The annual risk of a hemorrhage occurring during the latency period was 2.0% and the rate of hemorrhage-related morbidity and mortality was 1.6%. Multivariate analysis showed that decreased prescription dose (p < 0.001) and multiple draining veins (p = 0.003) were independent predictors of postradiosurgery hemorrhage. The rates of symptomatic and permanent radiation-induced changes were 8% and 2.7%, respectively. In the multivariate analysis, a single draining vein (p < 0.001) and higher Virginia RAS score (p = 0.005) were independent predictors of radiation-induced changes following radiosurgery. Conclusions Radiosurgery effectively treats ruptured AVMs with an acceptably low risk-to-benefit ratio. For patients with ruptured AVMs, favorable outcomes are more likely when preradiosurgical embolization is avoided and a higher prescription dose can be delivered.

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Radiosurgery for patients with unruptured intracranial arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/2013.2.jns121239 ◽

2013 ◽

Vol 118 (5) ◽

pp. 958-966 ◽

Cited By ~ 92

Author(s):

Dale Ding ◽

Chun-Po Yen ◽

Zhiyuan Xu ◽

Robert M. Starke ◽

Jason P. Sheehan

Keyword(s):

Arteriovenous Malformations ◽

Cox Regression ◽

Univariate Analysis ◽

Cyst Formation ◽

Intracranial Arteriovenous Malformations ◽

Radiation Induced ◽

Prescription Dose ◽

Martin Grade ◽

The Mean ◽

Induced Changes

Object The appropriate management of unruptured intracranial arteriovenous malformations (AVMs) remains controversial. In the present study, the authors evaluate the radiographic and clinical outcomes of radiosurgery for a large cohort of patients with unruptured AVMs. Methods From a prospective database of 1204 cases of AVMs involving patients treated with radiosurgery at their institution, the authors identified 444 patients without evidence of rupture prior to radiosurgery. The patients' mean age was 36.9 years, and 50% were male. The mean AVM nidus volume was 4.2 cm3, 13.5% of the AVMs were in a deep location, and 44.4% were at least Spetzler-Martin Grade III. The median radiosurgical prescription dose was 20 Gy. Univariate and multivariate Cox regression analyses were used to determine risk factors associated with obliteration, postradiosurgery hemorrhage, radiation-induced changes, and postradiosurgery cyst formation. The mean duration of radiological and clinical follow-up was 76 months and 86 months, respectively. Results The cumulative AVM obliteration rate was 62%, and the postradiosurgery annual hemorrhage rate was 1.6%. Radiation-induced changes were symptomatic in 13.7% and permanent in 2.0% of patients. The statistically significant independent positive predictors of obliteration were no preradiosurgery embolization (p < 0.001), increased prescription dose (p < 0.001), single draining vein (p < 0.001), radiological presence of radiation-induced changes (p = 0.004), and lower Spetzler-Martin grade (p = 0.016). Increased volume and higher Pittsburgh radiosurgery-based AVM score were predictors of postradiosurgery hemorrhage in the univariate analysis only. Clinical deterioration occurred in 30 patients (6.8%), more commonly in patients with postradiosurgery hemorrhage (p = 0.018). Conclusions Radiosurgery afforded a reasonable chance of obliteration of unruptured AVMs with relatively low rates of clinical and radiological complications.

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Radiosurgery for low-grade intracranial arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/2014.1.jns131713 ◽

2014 ◽

Vol 121 (2) ◽

pp. 457-467 ◽

Cited By ~ 66

Author(s):

Dale Ding ◽

Chun-Po Yen ◽

Zhiyuan Xu ◽

Robert M. Starke ◽

Jason P. Sheehan

Keyword(s):

Arteriovenous Malformations ◽

Proportional Hazards ◽

Cox Proportional Hazards ◽

Low Grade ◽

Surgical Morbidity ◽

Radiation Induced ◽

Prescription Dose ◽

Martin Grade ◽

Induced Changes

Object Low-grade, or Spetzler-Martin (SM) Grades I and II, arteriovenous malformations (AVMs) are associated with lower surgical morbidity rates than higher-grade lesions. While radiosurgery is now widely accepted as an effective treatment approach for AVMs, the risks and benefits of the procedure for low-grade AVMs, as compared with microsurgery, remain poorly understood. The authors of this study present the outcomes for a large cohort of low-grade AVMs treated with radiosurgery. Methods From an institutional radiosurgery database comprising approximately 1450 AVM cases, all patients with SM Grade I and II lesions were identified. Patients with less than 2 years of radiological follow-up, except those with complete AVM obliteration, were excluded from analysis. Univariate and multivariate Cox proportional-hazards and logistic regression analyses were used to determine factors associated with obliteration, radiation-induced changes (RICs), and hemorrhage following radiosurgery. Results Five hundred two patients harboring low-grade AVMs were eligible for analysis. The median age was 35 years, 50% of patients were male, and the most common presentation was hemorrhage (47%). The median AVM volume and prescription dose were 2.4 cm3 and 23 Gy, respectively. The median radiological and clinical follow-up intervals were 48 and 62 months, respectively. The cumulative obliteration rate was 76%. The median time to obliteration was 40 months, and the actuarial obliteration rates were 66% and 80% at 5 and 10 years, respectively. Independent predictors of obliteration were no preradiosurgery embolization (p < 0.001), decreased AVM volume (p = 0.005), single draining vein (p = 0.013), lower radiosurgery-based AVM scale score (p = 0.016), and lower Virginia Radiosurgery AVM Scale (Virginia RAS) score (p = 0.001). The annual postradiosurgery hemorrhage rate was 1.4% with increased AVM volume (p = 0.034) and lower prescription dose (p = 0.006) as independent predictors. Symptomatic and permanent RICs were observed in 8.2% and 1.4% of patients, respectively. No preradiosurgery hemorrhage (p = 0.011), a decreased prescription dose (p = 0.038), and a higher Virginia RAS score (p = 0.001) were independently associated with postradiosurgery RICs. Conclusions Spetzler-Martin Grade I and II AVMs are very amenable to successful treatment with stereotactic radiosurgery. While patient, physician, and institutional preferences frequently dictate the final course of treatment, radiosurgery offers a favorable risk-to-benefit profile for the management of low-grade AVMs.

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Repeat Radiosurgery for Intracranial Arteriovenous Malformations

Neurosurgery ◽

10.1227/neu.0b013e31822c5740 ◽

2011 ◽

Vol 70 (1) ◽

pp. 150-154 ◽

Cited By ~ 11

Author(s):

John M. Stahl ◽

Yueh-Yun Chi ◽

William A. Friedman

Keyword(s):

Initial Treatment ◽

Arteriovenous Malformations ◽

Intracranial Arteriovenous Malformations ◽

University Of Florida ◽

The Status ◽

Median Volume ◽

Radiation Induced ◽

Prescription Dose ◽

The University

Abstract BACKGROUND Despite a high success rate in the stereotactic radiosurgical treatment of intracranial arteriovenous malformations (AVMs) that cannot be safely resected with microsurgery, some patients must be managed after treatment failure. OBJECTIVE To provide an update on the use of repeat linear accelerator radiosurgery as a treatment for failed AVM radiosurgery at the University of Florida. METHODS We reviewed 103 patients who underwent repeat radiosurgical treatment for residual AVM at the University of Florida between December 1991 and December 2007. Each of these patients had at least 2 radiosurgical treatments for the same AVM. Patient information, including AVM nidus volume, prescription dose, age, and sex, was collected at the time of initial treatment and again at the time of retreatment. Patients were followed up after treatment with magnetic resonance, computed tomography, and angiographic imaging at standard intervals to determine the status of their AVM. The median follow-up after retreatment was 31 months. RESULTS Between the first and second treatments, the median AVM nidus volume was decreased by 69% (from a median volume of 12.7 to 4.0 cm3), allowing the median prescribed dose to be increased from 1500 cGy on initial treatment to 1750 cGy on retreatment. The final obliteration rate on retreatment was 65.3%. After salvage retreatment, 5 patients (4.9%) experienced radiation-induced complications, and 6 patients (5.8%) experienced posttreatment hemorrhage. CONCLUSION Repeat radiosurgery is a safe and effective salvage treatment for AVMs.

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Radiosurgery for Spetzler-Martin Grade III arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/2013.12.jns131041 ◽

2014 ◽

Vol 120 (4) ◽

pp. 959-969 ◽

Cited By ~ 55

Author(s):

Dale Ding ◽

Chun-Po Yen ◽

Robert M. Starke ◽

Zhiyuan Xu ◽

Xingwen Sun ◽

...

Keyword(s):

Arteriovenous Malformations ◽

Latency Period ◽

Cox Proportional Hazards ◽

Favorable Outcome ◽

Obliteration Rate ◽

Presenting Symptoms ◽

Prescription Dose ◽

Martin Grade ◽

Grade Iii

Object Intracranial arteriovenous malformations (AVMs) are most commonly classified based on their Spetzler-Martin grades. Due to the composition of the Spetzler-Martin grading scale, Grade III AVMs are the most heterogeneous, comprising 4 distinct lesion subtypes. The management of this class of AVMs and the optimal treatment approach when intervention is indicated remain controversial. The authors report their experience with radiosurgery for the treatment of Grade III AVMs in a large cohort of patients. Methods All patients with Spetzler-Martin Grade III AVMs treated with radiosurgery at the University of Virginia over the 20-year span from 1989 to 2009 were identified. Patients who had less than 2 years of radiological follow-up and did not have evidence of complete obliteration during that period were excluded from the study, leaving 398 cases for analysis. The median patient age at treatment was 31 years. The most common presenting symptoms were hemorrhage (59%), seizure (20%), and headache (10%). The median AVM volume was 2.8 cm3, and the median prescription dose was 20 Gy. The median radiological and clinical follow-up intervals were 54 and 68 months, respectively. Univariate and multivariate Cox proportional hazards and logistic regression analysis were used to identify factors associated with obliteration, postradiosurgery radiation-induced changes (RIC), and favorable outcome. Results Complete AVM obliteration was observed in 69% of Grade III AVM cases at a median time of 46 months after radiosurgery. The actuarial obliteration rates at 3 and 5 years were 38% and 60%, respectively. The obliteration rate was higher in ruptured AVMs than in unruptured ones (p < 0.001). Additionally, the obliteration rate for Grade III AVMs with small size (< 3 cm diameter), deep venous drainage, and location in eloquent cortex was higher than for the other subtypes (p < 0.001). Preradiosurgery AVM rupture (p = 0.016), no preradiosurgery embolization (p = 0.003), increased prescription dose (p < 0.001), fewer isocenters (p = 0.006), and a single draining vein (p = 0.018) were independent predictors of obliteration. The annual risk of postradiosurgery hemorrhage during the latency period was 1.7%. Two patients (0.5%) died of hemorrhage during the radiosurgical latency period. The rates of symptomatic and permanent RIC were 12% and 4%, respectively. Absence of preradiosurgery AVM rupture (p < 0.001) and presence of a single draining vein (p < 0.001) were independent predictors of RIC. Favorable outcome was observed in 63% of patients. Independent predictors of favorable outcome were no preradiosurgery hemorrhage (p = 0.014), increased prescription dose (p < 0.001), fewer isocenters (p = 0.014), deep location (p = 0.014), single draining vein (p = 0.001), and lower Virginia radiosurgery AVM scale score (p = 0.016). Conclusions Radiosurgery for Spetzler-Martin Grade III AVMs yields relatively high rates of obliteration with a low rate of adverse procedural events. Small and ruptured lesions are more likely to become obliterated after radiosurgery than large and unruptured ones.

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Radiosurgical treatment for rolandic arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/jns.2006.105.5.689 ◽

2006 ◽

Vol 105 (5) ◽

pp. 689-697 ◽

Cited By ~ 29

Author(s):

Yuri M. Andrade-Souza ◽

Meera Ramani ◽

Daryl Scora ◽

May N. Tsao ◽

Karel terBrugge ◽

...

Keyword(s):

Arteriovenous Malformations ◽

Latency Period ◽

Obliteration Rate ◽

University Of Toronto ◽

First Choice ◽

Study Population ◽

Radiation Induced ◽

Risk Of Hemorrhage ◽

The University

Object The authors reviewed the radiosurgical outcomes in patients with arteriovenous malformations (AVMs) located in the rolandic area, including the primary motor and sensory gyri. Methods The study population consisted of 38 patients with rolandic-area AVMs who underwent linear accelerator radiosurgery at the University of Toronto between 1989 and 2000. Obliteration rate, risk of hemorrhage during the latency period, radiation-induced complications, seizure control, and functional status were evaluated. Patients were also divided into two subgroups according to AVM volume (< 3 cm3 and ≥ 3 cm3). Patients were followed up for a median of 42.4 months (range 30–103 months), and the median age of the patients was 40 years (range 12–67 years). The median AVM volume was 8.1 cm3 (range 0.32–21, mean 8.32 cm3), and the median dose at the tumor margin was 15 Gy (range 15–22, mean 16.8 Gy). The risk of hemorrhage after radiosurgery was 5.3% for the 1st year, 2.6% for the 2nd, and 0% for the 3rd. Two patients (5.3%) sustained adverse effects related to radiation for more than 6 months. Complete nidus obliteration after a single radiosurgical treatment was achieved in 23 patients (60.5%). The obliteration rate for AVMs smaller than 3 cm3 was 83.3% (10 of 12) and that for AVMs larger than or equal to 3 cm3 was 50% (13 of 26). Among the patients who had seizures as the initial presentation, 51.8% were free of seizures after radiosurgery and the seizure pattern improved in 40.7% during the 3rd and last year of follow up. Overall, excellent results (obliteration and no new or worsening neurological deficit) can be achieved in approximately 60% of patients. This percentage varies according to the AVM size and can reach 83% in patients with AVMs smaller than 3 cm3. Conclusions Radiosurgery is a safe and effective treatment for people with rolandic AVMs. The low rate of morbidity associated with radiosurgery, compared with other treatments, indicates that this method may be the first choice for patients with AVMs located in this area.

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International multicenter cohort study of pediatric brain arteriovenous malformations. Part 2: Outcomes after stereotactic radiosurgery

Journal of Neurosurgery Pediatrics ◽

10.3171/2016.9.peds16284 ◽

2017 ◽

Vol 19 (2) ◽

pp. 136-148 ◽

Cited By ~ 31

Author(s):

Robert M. Starke ◽

Dale Ding ◽

Hideyuki Kano ◽

David Mathieu ◽

Paul P. Huang ◽

...

Keyword(s):

Cohort Study ◽

Stereotactic Radiosurgery ◽

Arteriovenous Malformations ◽

Latency Period ◽

Favorable Outcome ◽

Brain Arteriovenous Malformations ◽

Radiation Induced ◽

The Mean ◽

Induced Changes

OBJECTIVE Pediatric patients (age < 18 years) harboring brain arteriovenous malformations (AVMs) are burdened with a considerably higher cumulative lifetime risk of hemorrhage than adults. Additionally, the pediatric population was excluded from recent prospective comparisons of intervention versus conservative management for unruptured AVMs. The aims of this multicenter, retrospective cohort study are to analyze the outcomes after stereotactic radiosurgery for unruptured and ruptured pediatric AVMs. METHODS We analyzed and pooled AVM radiosurgery data from 7 participating in the International Gamma Knife Research Foundation. Patients younger than 18 years of age who had at least 12 months of follow-up were included in the study cohort. Favorable outcome was defined as AVM obliteration, no post-radiosurgical hemorrhage, and no permanently symptomatic radiation-induced changes (RIC). The post-radiosurgery outcomes of unruptured versus ruptured pediatric AVMs were compared, and statistical analyses were performed to identify predictive factors. RESULTS The overall pediatric AVM cohort comprised 357 patients with a mean age of 12.6 years (range 2.8–17.9 years). AVMs were previously treated with embolization, resection, and fractionated external beam radiation therapy in 22%, 6%, and 13% of patients, respectively. The mean nidus volume was 3.5 cm3, 77% of AVMs were located in eloquent brain areas, and the Spetzler-Martin grade was III or higher in 59%. The mean radiosurgical margin dose was 21 Gy (range 5–35 Gy), and the mean follow-up was 92 months (range 12–266 months). AVM obliteration was achieved in 63%. During a cumulative latency period of 2748 years, the annual post-radiosurgery hemorrhage rate was 1.4%. Symptomatic and permanent radiation-induced changes occurred in 8% and 3%, respectively. Favorable outcome was achieved in 59%. In the multivariate logistic regression analysis, the absence of prior AVM embolization (p = 0.001) and higher margin dose (p < 0.001) were found to be independent predictors of a favorable outcome. The rates of favorable outcome for patients treated with a margin dose ≥ 22 Gy vs < 22 Gy were 78% (110/141 patients) and 47% (101/216 patients), respectively. A margin dose ≥ 22 Gy yielded a significantly higher probability of a favorable outcome (p < 0.001). The unruptured and ruptured pediatric AVM cohorts included 112 and 245 patients, respectively. Ruptured AVMs had significantly higher rates of obliteration (68% vs 53%, p = 0.005) and favorable outcome (63% vs 51%, p = 0.033), with a trend toward a higher incidence of post-radiosurgery hemorrhage (10% vs 4%, p = 0.07). The annual post-radiosurgery hemorrhage rates were 0.8% for unruptured and 1.6% for ruptured AVMs. CONCLUSIONS Radiosurgery is a reasonable treatment option for pediatric AVMs. Obliteration and favorable outcomes are achieved in the majority of patients. The annual rate of latency period hemorrhage after radiosurgery for both ruptured and unruptured pediatric AVM patients conveys a significant risk until the nidus is obliterated.

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Stereotactic radiosurgery with and without embolization for intracranial arteriovenous malformations: a systematic review and meta-analysis

Neurosurgical FOCUS ◽

10.3171/2014.6.focus14178 ◽

2014 ◽

Vol 37 (3) ◽

pp. E16 ◽

Cited By ~ 25

Author(s):

Feng Xu ◽

Junjie Zhong ◽

Abhishek Ray ◽

Sunil Manjila ◽

Nicholas C. Bambakidis

Keyword(s):

Stereotactic Radiosurgery ◽

Arteriovenous Malformations ◽

Meta Analysis ◽

Neurological Deficits ◽

Current Evidence ◽

Secondary Outcome ◽

Intracranial Arteriovenous Malformations ◽

Obliteration Rate ◽

Radiation Induced ◽

Induced Changes

Object The effectiveness and risk of stereotactic radiosurgery (SRS) in the management of partially embolized intracranial arteriovenous malformations (AVMs) remain controversial. The aim of this analysis was to assess current evidence regarding the efficiency and safety of SRS for AVM patients with and without prior embolization. Methods To compare SRS in patients with and without embolization, the authors conducted a meta-analysis of studies by searching the literature via PubMed and EMBASE for the period between January 2000 and December 2013, complemented by a hand search. Primary outcome was the rate of AVM obliteration on a 3-year follow-up angiogram. Secondary outcome was the rate of hemorrhage at 3 years after SRS. Tertiary outcome was permanent neurological deficits related to radiation-induced changes. Results Ten studies eligible for analysis included 1988 patients: 593 had undergone embolization followed by SRS and 1395 had undergone SRS alone. The AVM obliteration rate was significantly lower in patients who had undergone embolization followed by SRS than in those who had undergone SRS alone (41.0% vs 59%, OR 0.46, 95% CI 0.37–0.56, p < 0.00001). However, the rates of hemorrhage (7.3% vs 5.6%, OR 1.17, 95% CI 0.74–1.83, p = 0.50) and permanent neurological deficits related to radiation-induced changes (3.3% vs 3.4%, OR 1.41, 95% CI 0.64–3.11, p = 0.39) were not significantly different between the two groups. Conclusions Embolization before SRS significantly decreases the AVM obliteration rate. However, there is no significant difference in the risk of hemorrhage and permanent neurological deficits after SRS alone and following embolization. Further validation by well-designed prospective or randomized cohort studies is still needed.

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Abstract 190: Hemorrhage of Cerebral Arteriovenous Malformations Significantly Alters Stereotactic Radiosurgery Outcomes

Stroke ◽

10.1161/str.46.suppl_1.190 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Dale Ding ◽

Chun-Po Yen ◽

Robert M Starke ◽

Zhiyuan Xu ◽

Jason P Sheehan

Keyword(s):

Arteriovenous Malformations ◽

Gamma Knife Radiosurgery ◽

Latency Period ◽

Cerebral Arteriovenous Malformations ◽

Patient Demographics ◽

Complete Obliteration ◽

Radiation Induced ◽

Prescription Dose ◽

Martin Grade ◽

Induced Changes

Introduction: Intracranial hemorrhage is simultaneously the most frequent and most debilitating manifestation of cerebral arteriovenous malformations (AVM), but its impact on success and complications of radiosurgery has not been rigorously assessed. In this case-control study, we define the effect of prior hemorrhage on AVM radiosurgery outcomes. Methods: From a prospective, institutional database of 1400 AVM patients treated with Gamma Knife radiosurgery, unruptured and ruptured AVMs were matched in a 1:1 fashion, blinded to outcome, based on patient demographics, prior embolization, AVM size (mean volume of unruptured AVMs 3.7 cm3 versus ruptured AVMs 3.5 cm3, P=0.195), Spetzler-Martin grade and radiosurgical treatment parameters (mean prescription dose for unruptured AVMs 20.9 Gy versus ruptured AVMs 21.0 Gy, P=0.837). There were 270 patients in each cohort. Matched statistical analyses were used to compare the baseline characteristics, obliteration rates, post-radiosurgery latency period hemorrhage risks, and incidences of radiation-induced changes (RIC) between the two cohorts. Results: The actuarial obliteration rates of the two cohorts were similar (unruptured AVMs: 38%, 58%, 76% at 3, 5, 10 years, respectively; ruptured AVMs: 40%, 60%, 73% at 3, 5, 10 years, respectively; P=0.592). However, for embolized AVMs, complete obliteration was more likely to be achieved in unruptured lesions (unruptured AVMs: 25%, 32%, 54% at 3, 5, 10 years, respectively; ruptured AVMs: 18%, 27%, 42% at 3, 5, 10 years, respectively; P=0.038). Prior AVM rupture resulted in a higher annual risk of post-radiosurgery latency period hemorrhage (ruptured AVMs 2.3% versus unruptured AVMs 1.1%, P=0.025) but a lower rate of cumulative and symptomatic RIC (cumulative RIC: ruptured AVMs 30.4% versus unruptured AVMs 48.9%, P<0.0001; symptomatic RIC: ruptured AVMs 7.0% versus unruptured AVMs 12.2%, P=0.041, respectively). The rates of permanent RIC were similar between the unruptured (2.2%) and ruptured (1.9%) AVM cohorts (P=0.761). Conclusion: Prior AVM rupture significantly alters the risk of latency period hemorrhage and RIC following radiosurgery. These effects should be taken into consideration with the multidisciplinary management of AVM patients.

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104 Stereotactic Radiosurgery for Spetzler-Martin Grade IV and V Arteriovenous Malformations: An International Multicenter Study

Neurosurgery ◽

10.1093/neuros/nyx417.104 ◽

2017 ◽

Vol 64 (CN_suppl_1) ◽

pp. 220-221

Author(s):

Jason P Sheehan ◽

Mohana Rao Patibandla ◽

Dale Ding ◽

Hideyuki Kano ◽

Zhiyuan Xu ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Arteriovenous Malformations ◽

Independent Predictor ◽

Multivariate Logistic Regression Analysis ◽

Favorable Outcome ◽

Single Session ◽

Radiation Induced ◽

International Multicenter Study ◽

Induced Changes

Abstract INTRODUCTION Due to the complexity of Spetzler-Martin (SM) grade IV-V arteriovenous malformations (AVM), the management of these lesions remains controversial. The aims of this multicenter, retrospective study are to evaluate outcomes after single-session stereotactic radiosurgery (SRS) for SM grade IV-V AVMs and determine predictive factors. METHODS We pooled data from 233 patients (mean age 33 years) with SM grade IV (94.4%) or V AVMs (5.6%) treated with single-session SRS at eight participating centers in the International Gamma Knife Research Foundation. Pre-SRS embolization was performed in 71 AVMs (30.5%). The mean nidus volume, SRS margin dose, and follow-up duration were 9.7 cc, 17.3 Gy, and 84.5 months, respectively. RESULTS >At a mean follow-up interval of 84.5 months, favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes (RIC) and was achieved in 26.2% of patients. The actuarial obliteration rates at 3, 7, 10, and 12 years were 15%, 34%, 37% and 42%, respectively. The annual post-SRS hemorrhage rate was 3.0%. Symptomatic and permanent RIC occurred in 10.7% and 4% of the patients, respectively. Only larger AVM diameter (P = 0.04) found to be an independent predictor of unfavorable outcome in the multivariate logistic regression analysis. The rate of favorable outcome was significantly lower for unruptured SM grade IV-V AVMs compared to ruptured ones (P = 0.042). Prior embolization was a negative independent predictor of AVM obliteration (P = 0.024) and radiologically evident RIC (P = 0.05) in multivariate analyses. CONCLUSION In this multi-institutional study, single session SRS had limited efficacy in the management of SM grade IV-V AVMs Favorable outcome was only achieved in a minority of unruptured SM grade IV-V AVMs, which supports less frequent utilization of SRS for the management of these lesions. A volume staged SRS approach for large AVMs represents an alternative approach for high grade AVM’s, but it requires further investigation.

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Radiosurgery for Unruptured Brain Arteriovenous Malformations: An International Multicenter Retrospective Cohort Study

Neurosurgery ◽

10.1093/neuros/nyx181 ◽

2017 ◽

Vol 80 (6) ◽

pp. 888-898 ◽

Cited By ~ 21

Author(s):

Dale Ding ◽

Robert M. Starke ◽

Hideyuki Kano ◽

John Y.K. Lee ◽

David Mathieu ◽

...

Keyword(s):

Cohort Study ◽

Retrospective Cohort Study ◽

Retrospective Cohort ◽

Arteriovenous Malformations ◽

Favorable Outcome ◽

Maximum Diameter ◽

Brain Arteriovenous Malformations ◽

Radiation Induced ◽

Induced Changes

Abstract BACKGROUND: The role of intervention in the management of unruptured brain arteriovenous malformations (AVM) is controversial. OBJECTIVE: To analyze in a multicenter, retrospective cohort study, the outcomes following radiosurgery for unruptured AVMs and determine predictive factors. METHODS: We evaluated and pooled AVM radiosurgery data from 8 institutions participating in the International Gamma Knife Research Foundation. Patients with unruptured AVMs and ≥12 mo of follow-up were included in the study cohort. Favorable outcome was defined as AVM obliteration, no postradiosurgical hemorrhage, and no permanently symptomatic radiation-induced changes. RESULTS: The unruptured AVM cohort comprised 938 patients with a median age of 35 yr. The median nidus volume was 2.4 cm3, 71% of AVMs were located in eloquent brain areas, and the Spetzler-Martin grade was III or higher in 57%. The median radiosurgical margin dose was 21 Gy and follow-up was 71 mo. AVM obliteration was achieved in 65%. The annual postradiosurgery hemorrhage rate was 1.4%. Symptomatic and permanent radiation-induced changes occurred in 9% and 3%, respectively. Favorable outcome was achieved in 61%. In the multivariate logistic regression analysis, smaller AVM maximum diameter (P = .001), the absence of AVM-associated arterial aneurysms (P = .001), and higher margin dose (P = .002) were found to be independent predictors of a favorable outcome. A margin dose ≥ 20 Gy yielded a significantly higher rate of favorable outcome (70% vs 36%; P < .001) CONCLUSION: Radiosurgery affords an acceptable risk to benefit profile for patients harboring unruptured AVMs. These findings justify further prospective studies comparing radiosurgical intervention to conservative management for unruptured AVMs.

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