Staged-Volume Radiosurgery of Large Arteriovenous Malformations Improves Outcome by Reducing the Rate of Adverse Radiation Effects.
The treatment of large arteriovenous malformations (AVMs) remains challenging. Recently, staged-volume radiosurgery (SVRS) has become an option.



To compare the outcome of SVRS on large AVMs with our historical, single-stage radiosurgery (SSRS) series.



We have been prospectively collecting data of patients treated by SVRS since 2007. There were 84 patients who had a median age of 37 years (range, 9-62 years) who were treated until July 2013. The outcomes of 76 of those who had follow-ups available were analyzed and compared with the outcomes of 122 patients treated with the best SSRS technique.



There were 21.5% of AVMs that were deep seated, and 44% presented with hemorrhage resulting in 45% fixed neurological deficit. There were 14% of patients who had undergone embolization before radiosurgery. The median nidus treatment volume was 19.7 cm3 (6.65-68.7) and 17.5 Gy (13-22.5) prescription isodose was given. Of the 44 lesions having radiological follow-up at 4 years, 61.4% were completely obliterated. Previous embolization (50% with and 63% without) and higher Spetzler-Martin grades appeared to be the negative factors in successful obliteration, but treatment volume was not. Within 3 years after radiosurgery, the annual bleed rates of unruptured and previously ruptured AVMs were 3.2% and 5.6%, respectively. Three bleeds were fatal and 2 resulted in significant modified Rankin scale 3 morbidity. These rates differ little from SSRS. Temporary adverse radiation effects (AREs) did not change significantly, but permanent AREs dropped from 15% to 6.5% (P = .03) compared with SSRS.



Obliteration and hemorrhage rates of large AVMs treated by SVRS are similar to historical SSRS. However, SVRS offers a lower rate of AREs.
National Institute of Clinical Neurosciences, Budapest, Hungary.
Gábor
G
Nagy
National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom.
Alison
A
Grainger
Department of Radiology, Royal Hallamshire Hospital, Sheffield, United Kingdom.
Timothy J
TJ
Hodgson
National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom.|Department of Neurosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom|Thornbury Radiosurgery Centre, Sheffield, United Kingdom
Jeremy G
JG
Rowe
Department of Radiology, Royal Hallamshire Hospital, Sheffield, United Kingdom.
Stuart C
SC
Coley
Thornbury Radiosurgery Centre, Sheffield, United Kingdom.
Andras A
AA
Kemeny
National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom.|Department of Neurosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom|Thornbury Radiosurgery Centre, Sheffield, United Kingdom
Matthias W R
MW
Radatz
D000293:Adolescent; D000328:Adult; D002648:Child; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000532:radiotherapy*; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult