Stereotactic radiosurgery for cerebellar arteriovenous malformations: an international multicenter study

Headache and Visual Aura Outcomes After Stereotactic Radiosurgery for Patients With Occipital Lobe Arteriovenous Malformations: A Single-Center Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

Patients with brain arteriovenous malformations (BAVMs) sometimes experience migraine-like chronic headaches. Reportedly, this symptom is common in occipital lobe BAVMs; however, the exact prevalence has not been clarified, and the details of visual auras have been scarcely reported. Furthermore, no comprehensive studies exist on the improvement of migraine associated with visual auras in occipital lobe BAVMs after stereotactic radiosurgery (SRS). Therefore, this study investigated the prevalence of headache with visual aura in patients with occipital lobe BAVMs and evaluated the impact of SRS on preexisting symptoms.

METHODS

As a single-center retrospective cohort study, a total of 104 patients with occipital lobe BAVMs treated with SRS from 1990 to 2024 were analyzed. Pre-SRS and post-SRS symptoms of headache and visual aura were documented. The outcomes measured were headache severity, frequency, aura characteristics, and BAVM obliteration rates.

RESULTS

Of the 104 patients, 41 (39%) reported chronic headache pre-SRS, and 37 (36%) experienced migraine with visual aura. Compared with pre-SRS, 90% (28/31) of the patients experienced a >50% reduction in headache severity and frequency at a median follow-up of 11 months, and 89% (25/28) experienced a >50% reduction in aura frequency. Complete headache remission was achieved in 35% (13/31) of patients. Complete obliteration of BAVMs was confirmed in 75% (76/102) of the patients at a median of 33 months. A smaller nidus volume was associated with both complete headache remission and BAVM obliteration, whereas age and sex were not significant predictors of headache outcome.

CONCLUSION

Patients with occipital lobe BAVMs frequently experience migraine-like headaches with visual aura, which may be more prevalent than in the general population. SRS for occipital lobe BAVMs could not only achieve favorable BAVM obliteration with minimal adverse effects but also significantly improve migraine-like symptoms, including visual aura, particularly in patients with smaller nidus volumes.

Long-term outcome of a tailored embolization strategy with Gamma Knife radiosurgery for high-grade brain arteriovenous malformations: a single-center experience

OBJECTIVE

The safety and efficacy of embolization with Gamma Knife radiosurgery (GKRS) for high-grade brain arteriovenous malformations (bAVMs) are uncertain. The purpose of this study was to elucidate the long-term outcome of a tailored embolization strategy with GKRS and identify the independent factors associated with bAVM obliteration.

METHODS

Between January 2014 and January 2017, a consecutive cohort of 159 patients with high-grade bAVMs who underwent embolization with GKRS was enrolled in this prospective single-center cohort study. All patients received a tailored embolization strategy with GKRS. The primary outcome was defined as bAVM obliteration. Secondary outcomes were neurological function and complications.

RESULTS

After a mean follow-up of 40.4 months, 5 patients were lost to follow-up. One hundred eighteen of the remaining 154 patients had favorable neurological outcomes with complete bAVM obliteration. A decrease in bAVM nidus size was observed in 36 patients. Five patients developed intracranial hemorrhage during the latency period, and 2 patients died. The Kaplan-Meier analysis showed that the obliteration rate increased each year and reached the peak point at approximately 3 years. The multivariate Cox regression analysis of factors affecting bAVM obliteration revealed that postembolization bAVM volume < 10 cm3 (p = 0.02), supratentorial location (p < 0.01), staged embolization prior to GKRS (p < 0.01), and mean Spetzler-Martin (SM) grade (p < 0.01) were independent factors associated with a high obliteration rate.

CONCLUSIONS

These data suggested that high-grade bAVMs treated using a tailored embolization strategy with GKRS were associated with a favorable clinical outcome and obliteration rate. Postembolization bAVM volume < 10 cm3, supratentorial location, staged embolization prior to GKRS, and low mean SM grade were associated with a high obliteration rate.

Effect of embolization before stereotactic radiosurgery for brain arteriovenous malformations: a case-control study with propensity score matching

OBJECTIVE

The aim of this study was to evaluate whether endovascular embolization prior to stereotactic radiosurgery (SRS) has a negative impact on nidus obliteration for patients with arteriovenous malformations (AVMs).

METHODS

A total of 704 eligible patients with AVM who did not undergo prior surgery or radiotherapy were evaluated. Of these patients, 593 were treated with SRS only, and 111 were treated with embolization followed by SRS (E+SRS). Most patients in the E+SRS group (88%) underwent embolization with n-butyl-2-cyanoacrylate. In the comparison of radiosurgical outcomes between patients treated with SRS only and E+SRS, these groups were matched in a 1:1 ratio using propensity score matching to eliminate differences in basic characteristics. The primary outcome was to compare the nidus obliteration rates between the SRS-only and E+SRS groups. The secondary outcomes were the comparison of cumulative hemorrhage rates and the incidence of cyst formation or chronic encapsulated hematoma after SRS between these groups.

RESULTS

In the unmatched cohorts, the actuarial 3-, 5-, and 8-year nidus obliteration rates after a single SRS session were 49.6%, 69.4%, and 74.1% in the SRS-only group, respectively, and 30.7%, 50.9%, and 68.6% in the E+SRS group, respectively (p = 0.001). In the matched cohort of 98 patients in each group, the rates were 47.1%, 62.0%, and 69.6% in the SRS-only group and 32.5%, 55.3%, and 75.0% in the E+SRS group, respectively (p = 0.24). There was no significant difference in either cumulative hemorrhage or the incidence of cyst formation or chronic encapsulated hematoma between the groups.

CONCLUSIONS

Pre-SRS embolization did not affect nidus obliteration rates, cumulative hemorrhage rates, or the incidence of cyst formation or chronic encapsulated hematoma as late adverse radiation effects in patients with AVM treated with SRS.

Intracranial arteriovenous malformations

The treatment of arteriovenous malformations (AVMs) has evolved over the last 10 years. It is now possible to see that obliteration continues for up to 10 years and that the final obliteration rate may be between 85% and 90%. Improved imaging has made the treatment more efficient and has reduced the complications. It is possible to treat larger AVMs in a single session than was previously thought possible without increases in the complication rates. In addition, treatments of larger lesions can be staged. The use of 3D rotating angiography produces remarkable images which can be imported into GammaPlan. On the other hand efforts are ongoing to avoid the need for digital subtraction angiography, which would make the treatment a lot more comfortable.

Presence of direct vertebrobasilar perforator feeders in posterior fossa arteriovenous malformations and association with poor outcomes after endovascular treatment

OBJECTIVE

Treatment of posterior fossa arteriovenous malformations (PFAVMs) remains controversial as it is always challenging and may lead to major complications. Nonetheless, these lesions are more likely to bleed and generate poorer outcomes than other brain AVMs. The aim of this study was to evaluate the effect of endovascular treatment on long-term outcomes and identify the patient subgroups that might benefit from endovascular treatment.

METHODS

The authors performed a retrospective analysis of all consecutive cases of PFAVM managed at the Fondation Rothschild Hospital between 1995 and 2018. Clinical, imaging, and treatment data were prospectively gathered; these data were analyzed with respect to long-term outcomes.

RESULTS

Among the 1311 patients with brain AVMs, 114 (8.7%) had a PFAVM, and 88 (77.2%) of these patients had a history of bleeding. Of the 114 PFAVMs, 101 (88.6%) were treated (83 ruptured and 18 unruptured). The mean duration of follow-up was 47.6 months (range 0-240 months). Good neurological outcome at last follow-up was achieved in 79 cases (78.2%). Follow-up angiography showed obliteration of the PFAVM in 68.3% of treated cases. The presence of direct vertebrobasilar perforator feeders was associated with neurological deterioration (OR 5.63, 95% CI 11.15-30.76) and a lower obliteration rate (OR 15.69, 95% CI 2.52-304.03) after endovascular treatment. Other predictors of neurological deterioration and obliteration rate were consistent with the Spetzler-Martin grading system.

CONCLUSIONS

Advances in endovascular techniques have enabled higher obliteration rates in the treatment of PFAVMs, but complication rates are still high. Subgroups of patients who might benefit from treatment must be carefully selected and the presence of direct vertebrobasilar perforator feeders must call into question the indication for endovascular treatment.

Trigeminal Neuralgia Secondary to Cerebellar Arteriovenous Malformation: A Report of Two Cases

Trigeminal neuralgia (TN) secondary to cerebellar arteriovenous malformation (cAVM) is a rare condition with only few reports existing in the literatures. Given to its rarity, the treatment armamentarium is still controversial. We reported our experiences treated two cases of TN secondary to cAVM using different strategies. The first case was successfully treated by a combination of gamma knife radiosurgery and microvascular decompression (MVD) of the trigeminal nerve. The second case was successfully treated by one-step microsurgical AVM resection and MVD of the trigeminal nerve. Postoperative immediate pain relief was achieved in both patients. Microsurgical procedure is still playing an important role in treating TN secondary to cAVM.

Hemorrhage risk of cerebral dural arteriovenous fistulas following Gamma Knife radiosurgery in a multicenter international consortium

OBJECTIVE

The authors performed a study to evaluate the hemorrhagic rates of cerebral dural arteriovenous fistulas (dAVFs) and the risk factors of hemorrhage following Gamma Knife radiosurgery (GKRS).

METHODS

Data from a cohort of patients undergoing GKRS for cerebral dAVFs were compiled from the International Radiosurgery Research Foundation. The annual posttreatment hemorrhage rate was calculated as the number of hemorrhages divided by the patient-years at risk. Risk factors for dAVF hemorrhage prior to GKRS and during the latency period after radiosurgery were evaluated in a multivariate analysis.

RESULTS

A total of 147 patients with dAVFs were treated with GKRS. Thirty-six patients (24.5%) presented with hemorrhage. dAVFs that had any cortical venous drainage (CVD) (OR = 3.8, p = 0.003) or convexity or torcula location (OR = 3.3, p = 0.017) were more likely to present with hemorrhage in multivariate analysis. Half of the patients had prior treatment (49.7%). Post-GRKS hemorrhage occurred in 4 patients, with an overall annual risk of 0.84% during the latency period. The annual risks of post-GKRS hemorrhage for Borden type 2-3 dAVFs and Borden type 2-3 hemorrhagic dAVFs were 1.45% and 0.93%, respectively. No hemorrhage occurred after radiological confirmation of obliteration. Independent predictors of hemorrhage following GKRS included nonhemorrhagic neural deficit presentation (HR = 21.6, p = 0.027) and increasing number of past endovascular treatments (HR = 1.81, p = 0.036).

CONCLUSIONS

Patients have similar rates of hemorrhage before and after radiosurgery until obliteration is achieved. dAVFs that have any CVD or are located in the convexity or torcula were more likely to present with hemorrhage. Patients presenting with nonhemorrhagic neural deficits and a history of endovascular treatments had higher risks of post-GKRS hemorrhage.

Endovascular treatment of cerebellar arteriovenous malformations: A single-center experience of 75 consecutive patients

AIM

We aimed to determine the safety and effectiveness of endovascular treatment for cerebellar arteriovenous malformations (AVMs).

MATERIALS AND METHODS

Between January 2006 and January 2016, 75 patients with cerebellar AVMs underwent endovascular treatment at our department. The clinical and angiographic features, post-procedure complications, occlusion rate, and follow-up outcomes (modified Rankin Scale, mRS) of all the patients were retrospectively reviewed and collected. Multivariable logistic analysis was used to calculate potential risk factors for predicting poor outcomes (mRS ≥3).

RESULTS

Of the 75 patients, 61 (81.3%) presented with initial hemorrhage, and 44 (58.7%) presented with 63 cerebral aneurysms. Immediate digital subtraction angiography (DSA) after the procedure showed complete occlusion of the cerebral aneurysms in all the patients, and total occlusion of the AVM nidus in 32/75 (42.7%) patients, 99-90% occlusion in 31/75 (41.3%) patients, and <90% occlusion in 12/75 (16.0%) patients. Favorable functional outcome (mRS <3) was achieved in 61 (81.3%) patients. After adjusting for other factors, multivariate logistic analysis showed that increasing patient age (OR, 1.086; 95% CI, 1.098-1.182), the size of AVM (OR, 9.072; 95% CI, 1.164-20.703), and eloquent location (OR, 9.209; 95% CI, 1.557-35.481) were significantly independent predictors of poor outcome.

CONCLUSIONS

Endovascular treatment of cerebellar AVMs is safe and feasible. The high rate of associated cerebral aneurysms could explain the tendency of initial hemorrhage in cerebellar AVMs; targeted embolization of coexisting cerebral aneurysms should be the first priority. Increasing patient age, eloquent AVM location, and the size of AVM are independent predictors of poor outcome after endovascular treatment of cerebellar AVMs.

Evaluation of stereotactic radiosurgery for cerebral dural arteriovenous fistulas in a multicenter international consortium

OBJECTIVE

In this multicenter study, the authors reviewed the results obtained in patients who underwent Gamma Knife radiosurgery (GKRS) for dural arteriovenous fistulas (dAVFs) and determined predictors of outcome.

METHODS

Data from a cohort of 114 patients who underwent GKRS for cerebral dAVFs were compiled from the International Gamma Knife Research Foundation. Favorable outcome was defined as dAVF obliteration and no posttreatment hemorrhage or permanent symptomatic radiation-induced complications. Patient and dAVF characteristics were assessed to determine predictors of outcome in a multivariate logistic regression analysis; dAVF-free obliteration was calculated in a competing-risk survival analysis; and Youden indices were used to determine optimal radiosurgical dose.

RESULTS

A mean margin dose of 21.8 Gy was delivered. The mean follow-up duration was 4 years (range 0.5-18 years). The overall obliteration rate was 68.4%. The postradiosurgery actuarial rates of obliteration at 3, 5, 7, and 10 years were 41.3%, 61.1%, 70.1%, and 82.0%, respectively. Post-GRKS hemorrhage occurred in 4 patients (annual risk of 0.9%). Radiation-induced imaging changes occurred in 10.4% of patients; 5.2% were symptomatic, and 3.5% had permanent deficits. Favorable outcome was achieved in 63.2% of patients. Patients with middle fossa and tentorial dAVFs (OR 2.4, p = 0.048) and those receiving a margin dose greater than 23 Gy (OR 2.6, p = 0.030) were less likely to achieve a favorable outcome. Commonly used grading scales (e.g., Borden and Cognard) were not predictive of outcome. Female sex (OR 1.7, p = 0.03), absent venous ectasia (OR 3.4, p < 0.001), and cavernous carotid location (OR 2.1, p = 0.019) were predictors of GKRS-induced dAVF obliteration.

CONCLUSIONS

GKRS for cerebral dAVFs achieved obliteration and avoided permanent complications in the majority of patients. Those with cavernous carotid location and no venous ectasia were more likely to have fistula obliteration following radiosurgery. Commonly used grading scales were not reliable predictors of outcome following radiosurgery.

Integration of rotational angiography enables better dose planning in Gamma Knife radiosurgery for brain arteriovenous malformations

OBJECTIVE

In Gamma Knife radiosurgery (GKS) for arteriovenous malformations (AVMs), CT angiography (CTA), MRI, and digital subtraction angiography (DSA) are generally used to define the nidus. Although the AVM angioarchitecture can be visualized with superior resolution using rotational angiography (RA), the efficacy of integrating RA into the GKS treatment planning process has not been elucidated.

METHODS

Using data collected from 25 consecutive patients with AVMs who were treated with GKS at the authors’ institution, two neurosurgeons independently created treatment plans for each patient before and after RA integration. For all patients, MR angiography, contrasted T1 imaging, CTA, DSA, and RA were performed before treatment. The prescription isodose volume before (PIVB) and after (PIVA) RA integration was measured. For reference purposes, a reference target volume (RTV) for each nidus was determined by two other physicians independent of the planning surgeons, and the RTV covered by the PIV (RTVPIV) was established. The undertreated volume ratio (UVR), overtreated volume ratio (OVR), and Paddick’s conformal index (CI), which were calculated as RTVPIV/RTV, RTVPIV/PIV, and (RTVPIV)2/(RTV × PIV), respectively, were measured by each neurosurgeon before and after RA integration, and the surgeons’ values at each point were averaged. Wilcoxon signed-rank tests were used to compare the values obtained before and after RA integration. The percentage change from before to after RA integration was calculated for the average UVR (%ΔUVRave), OVR (%ΔOVRave), and CI (%ΔCIave) in each patient, as ([value after RA integration]/[value before RA integration] − 1) × 100. The relationships between prior histories and these percentage change values were examined using Wilcoxon signed-rank tests.

RESULTS

The average values obtained by the two surgeons for the median UVR, OVR, and CI were 0.854, 0.445, and 0.367 before RA integration and 0.882, 0.478, and 0.463 after RA integration, respectively. All variables significantly improved after compared with before RA integration (UVR, p = 0.009; OVR, p < 0.001; CI, p < 0.001). Prior hemorrhage was significantly associated with larger %ΔOVRave (median 20.8% vs 7.2%; p = 0.023) and %ΔCIave (median 33.9% vs 13.8%; p = 0.014), but not %ΔUVRave (median 4.7% vs 4.0%; p = 0.449).

CONCLUSIONS

Integrating RA into GKS treatment planning may permit better dose planning owing to clearer visualization of the nidus and, as such, may reduce undertreatment and waste irradiation. Further studies examining whether the observed RA-related improvement in dose planning also improves the radiosurgical outcome are needed.

Impact of Onyx Embolization on Radiosurgical Management of Cerebral Arteriovenous Malformations: Treatment and Outcome

BACKGROUND

Stereotactic radiosurgery (SRS) is a well-established treatment modality for cerebral arteriovenous malformations (AVMs). The main limiting factor in the radiosurgical treatment of AVMs is the volume of the nidus, with high-grade lesions often requiring combined treatment to reduce the SRS target volume. To overcome this limitation, we have been using a combined treatment approach consisting of endovascular embolization with Onyx followed by SRS.

OBJECTIVE

To evaluate our clinical experience for safety and feasibility of this multimodality treatment approach.

METHODS

This is a retrospective review of all adult patients with cerebral AVMs who received SRS treatment to their AVM after endovascular embolization with Onyx between June 2007 and June 2014.

RESULTS

Thirty-five consecutive patients were identified. The mean follow-up period was 52.4 ± 22.6 months (range 18-97 months). We confirmed 18 (51.4%) complete nidus closures at a median time of 49.5 months (range 6.5-81 months) from SRS. High-resolution Magnetic resonance imaging/magnetic resonance angiography was performed routinely in all patients until closure of the nidus. Digital subtraction angiography was performed to confirm complete obliteration in 5 of the patients (28%); 13 patients are either planned for digital subtraction angiography or have refused it. In 6 patients (17%) a significant flow reduction was noted after a mean of 32 ± 16 months. No significant improvement was observed in 9 patients (26%) during the follow-up period. Two patients were lost to follow-up.

CONCLUSIONS

The multimodality treatment of cerebral AVMs using embolization with Onyx followed by SRS is feasible and safe. The use of Onyx significantly reduced the SRS treatment target volume.