title: The incidence of imaging abnormalities after stereotactic radiosurgery for cerebral arteriovenous and cavernous malformations.
abstract: OBJECTIVE
  The aim of the study was to evaluate the incidence of postirradiation imaging changes after stereotactic radiosurgery for arteriovenous malformations (AVM) and cerebral cavernous malformations (CCM).
  
  
  METHODS
  A group of 85 patients treated for arteriovenous malformations (62 patients, 73%) and cavernomas (23 patients, 27%) between October 2001 and December 2005 was analyzed. All patients were treated with stereotactic radiosurgery with doses ranging from 8-28 Gy. After the irradiation, magnetic resonance imaging (MRI) or computed tomography (CT) was performed at 6 to 12-month intervals to assess the effects of the treatment. The mean follow-up time for the whole group was 27.3 months; AVM group -- 26 months; CCM group -- 30.9 months. All the imaging data were carefully reviewed to identify the radiological symptoms of postradiosurgical damage. T2 or FLAIR hyperintensity, T1-hypointensity and contrast enhancement on MRI and the presence of hypodense areas and contrast enhancement on CT examinations were assessed.
  
  
  RESULTS
  Imaging abnormalities were found in 28 (33%) patients. The symptoms of postradiosurgical damage were observed in 21 (33.9%) patients in the AVM group and 7 (30.4%) patients in the CCM group. Radiological symptoms of radiation necrosis associated with neurological deterioration were identified in two patients with cavernomas, while no radiation necrosis was found in the AVM group. Patients in whom radiological signs of focal brain edema or gliosis existed were asymptomatic.
  
  
  CONCLUSIONS
  Radiological symptoms of postradiosurgical damage affected about one third of the irradiated patients, typically without any clinical manifestations. Patients irradiated for CCMs seem to be more prone to develop symptomatic postradiosurgical necrosis; this observation, however, requires further investigation.
authors.affiliation: Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branchul, Gliwice, Poland. blamek@gmail.com
authors.forename: Sławomir
authors.initials: S
authors.lastname: Blamek
authors.forename: Marek
authors.initials: M
authors.lastname: Boba
authors.forename: Dawid
authors.initials: D
authors.lastname: Larysz
authors.forename: Adam
authors.initials: A
authors.lastname: Rudnik
authors.forename: Kornelia
authors.initials: K
authors.lastname: Ficek
authors.forename: Bartosz
authors.initials: B
authors.lastname: Eksner
authors.forename: Leszek
authors.initials: L
authors.lastname: Miszczyk
authors.forename: Rafał
authors.initials: R
authors.lastname: Tarnawski
mesh_terms: D000293:Adolescent; D001165:Arteriovenous Malformations / Q000145:classification / Q000473:pathology* / Q000601:surgery*; D001921:Brain / Q000473:pathology*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods