International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationThe Radiosurgical Treatment of Arteriovenous Malformations: Obliteration, Morbidities, and Performance Status
Introduction
Arteriovenous malformations (AVMs) of the brain are congenital vascular malformations that have an estimated detection rate of 1/100,000 person-years (1) and carry a 5% annual risk of bleeding caused by rupture (2), accounting for 2% of all hemorrhagic strokes (3). Patients may present with intracranial bleeding or neurologic symptoms such as headaches and/or seizures, or they may have no symptoms with incidental detection of the AVM. Stereotactic radiosurgery (SRS) is a promising alternative to surgical resection in the treatment of AVMs. Nidus size, prior hemorrhage, and embolization are some of the factors (4) that have been commonly, albeit inconsistently (5, 6), identified as predictive of complete obliteration. Radiosurgery-associated morbidities include seizures, headaches, neurologic deficits, and radiation-induced cerebral injury such as cysts or neoplasms. Moreover, the effect of irradiation manifests over a latency period of 1 to 3 years (7, 8), during which it has been shown (9, 10) that the risk of rebleeding remains constant and can be eliminated only by complete obliteration. Both the long latency period and the requirement of angiography to demonstrate cure have rendered follow-up especially difficult in large cohorts of AVM patients. Although many studies (11, 12) have investigated the anatomic and radiosurgical parameters that are correlated with complete AVM obliteration, few studies have examined the effect of radiosurgery on AVM-associated neurologic symptoms and the functional status of patients after radiosurgery, which is important in the evaluation of any procedure and its impact on patients' quality of life. The modified Rankin Scale (mRS) has been specifically adapted previously (13) to assess the performance status of AVM patients after radiosurgery.
Section snippets
Patients
Institutional Review Board approval was obtained to review the records of 217 consecutive patients treated for AVMs by stereotactic radiosurgery at the Johns Hopkins Hospital between 1990 and 2008. All information was then compiled in a database. To be eligible for inclusion in the study, patients either had obliteration confirmed by magnetic resonance imaging (MRI) and/or angiography, or had at least 24 months of follow-up after radiosurgery. In patients who had multiple radiosurgical
Obliteration rate and predictors of obliteration
Complete AVM obliteration was achieved in 81 patients (63.8%), of which 53 (65%) were confirmed by angiography and 28 (35%) by MRI only, because of either patient declining repeat angiography or loss to follow-up after MRI. Demographic and clinical characteristics of the patients by obliteration status are compared in Table 1. Patients without complete obliteration had a median follow-up time of 55 months, during which the volume of the AVM decreased by a median of 70% compared with before
AVM obliteration
The overall and single-treatment obliteration rates of 63.8% and 79.5%, respectively, are consistent with the 54–92% reported in other series (15, 16, 17). Patients who required multiple treatments experienced a drastically lower obliteration rate of 28.2%, and this disparity is likely a reflection of inherent differences in AVM characteristics. Patients who underwent more than one radiosurgical procedure tended to have larger AVMs and were more likely to have received embolization, both of
Conclusion
Radiosurgery offered complete obliteration of AVM in 64% of treated patients. Previous hemorrhage and larger marginal dose were positive predictors of obliteration, whereas prior embolization and larger AVM volume were negative predictors. Hemorrhage after radiosurgery occurred in 9.4% of patients (2.2% annual risk) and represent an annual mortality risk of 0.6–1.3%, whereas 11.0% experienced subacute neurologic complications after radiosurgery. Radiosurgery was effective in ameliorating AVM
References (40)
- et al.
Brain arteriovenous malformations in adults
Lancet Neurol
(2005) - et al.
Natural history of brain arteriovenous malformations: A long-term follow-up study of risk of hemorrhage in 238 patients
Neurosurgery
(2008) Arteriovenous malformations of the brain
N Engl J Med
(2007)- et al.
Stereotactic radiosurgery for arteriovenous malformations of the brain
J Neurosurg
(1991) - et al.
Does hemorrhagic presentation in cerebral arteriovenous malformations affect obliteration rate after gamma knife radiosurgery?
Clin Neurol Neurosurg
(2008) - et al.
Combined management of intracranial arteriovenous malformations with embolization and gamma knife radiosurgery: Comparative evaluations of the long-term results
Surg Neurol
(2009) - et al.
Factors related to complete occlusion of arteriovenous malformations after gamma knife radiosurgery
J Neurosurg
(2000) - et al.
Multidisciplinary approach to arteriovenous malformations
Neurol Med Chir
(1998) - et al.
Patient outcomes after arteriovenous malformation radiosurgical management: Results based on a 5- to 14-year follow-up study
Neurosurgery
(2003) - et al.
Management of patients with brain arteriovenous malformations
Eur J Raiol
(2003)
Analysis of factors predictive of success or complications in arteriovenous malformation radiosurgery
Neurosurgery
Can the probability for obliteration after radiosurgery for arteriovenous malformations be accurately predicted?
Int J Radiat Oncol Biol Phys
Use of modified Rankin Scale to assess outcome after arteriovenous malformation radiosurgery
Neurology
Repeat stereotactic radiosurgery for high-grade and large intracranial arteriovenous malformations
Surg Neurol
A dose-response analysis of arteriovenous malformation obliteration after radiosurgery
Int J Radiat Oncol Biol Phys
Hemorrhage risks and obliteration rates of arteriovenous malformations after gamma knife radiosurgery
J Neurosurg
Efficacy and morbidity of arc-therapy radiosurgery for cerebral arteriovenous malformations: A comparison with the natural history
Int J Radiat Oncol Biol Phys
Treatment outcome after Linac-based radiosurgery in cerebral arteriovenous malformations: Retrospective analysis of factors affecting obliteration
Radiother Oncol
Linac radiosurgery for cerebral arteriovenous malformations: Results in 169 patients
Int J Radiat Oncol Biol Phys
A comprehensive review of radiosurgery for cerebral arteriovenous malformations: Outcomes, predictive factors, and grading scales
Stereotact Funct Neurosurg
Cited by (41)
Dynamic conformal arc radiosurgery for arteriovenous malformations: Outcome and influence of clinical and dosimetrical data
2017, Radiotherapy and OncologyCitation Excerpt :Majority of AVM SRS studies concerns GK, considering its longer history of use. Linac-based SRS studies are generally based on shorter follow-up or lower prescription doses [13,14]. Gevaert described Novalis dynamic arctherapy SRS as delivering a homogeneous dose, in a short treatment time [15].
Risk of hemorrhage in patients over age 60 with arteriovenous malformations (AVMs)
2016, Journal of Clinical NeuroscienceCitation Excerpt :However, this is likely a result of incomplete follow-up bias given the extremely short follow-up period (0.3 patient-years); therefore, the benefit of functional outcome associated with Emb needs to be further investigated. Obliteration rate is 100.0% for SE, 43.8% for RE and 0.0% for EM, which is largely in concordance with current literature [26–28]. Interestingly, four patients in the Obs group experienced spontaneous obliteration of the lesion, of which three regressed after presenting with ICH.
Cerebral Arteriovenous Malformations and Epilepsy, Part 1: Predictors of Seizure Presentation
2015, World NeurosurgeryCerebral Arteriovenous Malformations and Epilepsy, Part 2: Predictors of Seizure Outcomes Following Radiosurgery
2015, World NeurosurgeryCitation Excerpt :Prior AVM hemorrhage was the strongest independent predictor of the lack of de novo seizures (OR = 9.7, 95% CI = 2.5–38.1), followed by higher Spetzler-Martin grade (OR = 2.2, 95% CI = 1.1–4.4). Compared with acute and devastating intracranial hemorrhage, the appreciation of seizure status in AVM presentation and treatment is relatively neglected (1, 23, 24, 57). Given that seizures are the most common presentation of unruptured AVMs and in light of the recently published prospective studies, A Randomized Trial of Unruptured Brain Arteriovenous Malformations and Scottish Audit of Intracranial Vascular Malformations, an improved understanding of seizure outcomes after interventions is crucial to optimizing the management of patients harboring AVMs (2, 37, 54).
Supported by grants from the Salisbury Foundation, the Monica and Hermen Greenberg Foundation, and the Swenson Foundation.
Conflict of interest: none.