title: Treatment of Cerebral Arteriovenous Malformations with Radiosurgery or Hypofractionated Stereotactic Radiotherapy in a Consecutive Pooled Linear Accelerator Series.
abstract: OBJECTIVE
  To review outcomes after linear accelerator stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (hfSRT) of arteriovenous malformations (AVMs) from a consecutive and pooled series of 2 Novalis centers and to analyze the influence of AVM size, Spetzler-Martin (SM) grade, pretreatment, and hemorrhagic versus nonhemorrhagic presentation. A subgroup analysis of A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA)-eligible patients also was performed.
  
  
  METHODS
  Prospectively collected treatment and outcome data were supplemented by retrospectively collected follow-up data for 93.8% of all patients. A total of 129 patients with AVM had SRS or hfSRT between 2000 and 2014 with the same linear accelerator system in 2 centers. Data analysis included initial presentation, SM grade, occlusion rates assessed by magnetic resonance and/or digital subtraction angiography, neurologic and therapeutic complications, and pretreatments. Statistical analysis was performed for patient demographic data and for factors potentially influencing outcome.
  
  
  RESULTS
  Initial presentation was hemorrhage in 43.8% or seizures/neurologic deficits in 46.2%. The series included 6 SM grade I (5%), 26 SM II (21.5%), 55 SM III (45.5%), 28 SM IV (23%), and 6 SM V cases (5%). Pre-embolization was used in 36 patients (29.8%), 8 patients had previous surgery (6.6%), and 6 patients were irradiated before elsewhere (5%); 5 patients (4.2%) received multimodal pretreatment. Mean follow-up was 43 months. The occlusion rate for the total series was 71.1%, for SM I/II cases 80.6%, and 67.4% for the SM ≥ subgroup. The occlusion rate was 75.0% for the small volume (<4 cc) and 55.6% for the large volume (>10 cc) subgroup. There was no statistical difference between the occlusion rate of patients with or without pretreatment if taken all modalities together (72.7% and 69.7%, respectively). There was only a trend of a belated occlusion of pre-embolized AVMs. The occlusion rate for hemorrhagic AVM was with 77.4% better than for nonhemorrhagic (66.2%) or ARUBA-eligible AVMs (64.8%) but without reaching statistical significance. Neurologic deterioration was seen in 13.2% of the patients. There were 2 re-bleedings within 17-18 months (1.7%), 1 of them without a new neurologic deficit and total occlusion after re-SRS. One patient with pre-existing epilepsy died a sudden unexpected death (mortality rate: 0.8%).
  
  
  CONCLUSIONS
  Overall SRS and hfSRT are valuable therapy options, especially in symptomatic patients with AVM, with a low rate of morbidity and mortality and an acceptable overall complete occlusion rate of >70% and >80% for SM I/II AVMs.
authors.affiliation: Department of Radiosurgery and Stereotactic Radiotherapy, MediClin Robert Janker Clinic and MediClin MVZ Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital of Bonn, Bonn, Germany. Electronic address: Jan.Bostroem@mediclin.de.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Boström
authors.affiliation: Department of Radiosurgery and Stereotactic Radiotherapy, MediClin Robert Janker Clinic and MediClin MVZ Bonn, Bonn, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Bruckermann
authors.affiliation: Department of Neurosurgery, University Hospital of Bonn, Bonn, Germany.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Pintea
authors.affiliation: Department of Neurosurgery, University Hospital of Bonn, Bonn, Germany.
authors.forename: Azize
authors.initials: A
authors.lastname: Boström
authors.affiliation: Department of Radiosurgery, HELIOS Klinikum Erfurt, Erfurt, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Surber
authors.affiliation: Department of Radiosurgery, HELIOS Klinikum Erfurt, Erfurt, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hamm
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000401:mortality* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D000069473:Radiation Dose Hypofractionation; D011832:Radiation Injuries / Q000401:mortality* / Q000517:prevention & control; D016634:Radiosurgery / Q000401:mortality* / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
keywords: ARUBA study; Cerebral arteriovenous malformation; Hypofractionated stereotactic radiotherapy; Linear accelerator–based radiosurgery; Outcome data; Radiosurgery