title: Stereotactic radiosurgery results in three cases of intramedullary spinal cord arteriovenous malformations.
abstract: BACKGROUND
  Intramedullary spinal cord arteriovenous malformations (AVMs) are rare and have an unfavorable prognosis. We report our experience of treating three symptomatic patients with stereotactic radiosurgery (SRS). The standard treatment for these lesions are embolization or microsurgical resection. There are only a few reports of efficacy of radiosurgery in these cases.
  
  
  OBJECTIVE
  To study the efficacy of radiosurgery in intramedullary spinal cord AVM patients, who failed or refused conventional treatment.
  
  
  METHODS
  This study reports the results of SRS in 3 cases of intramedullary spinal cord AVMs.
  
  
  METHODS
  Three symptomatic patients diagnosed with intramedullary spinal cord AVMs. Two patients underwent embolization previously and one was newly diagnosed.
  
  
  METHODS
  The AVM obliteration was assessed by yearly high-resolution magnetic resonance imaging (MRI). Clinical examination was carried out every 6 months.
  
  
  METHODS
  Three symptomatic patients with intramedullary spinal cord AVMs were treated with SRS using the cyberknife system from January 2010 to May 2011. All the three patients presented with acute neurologic symptoms. Two patients were treated previously with embolization. As per protocol, patients underwent a plain computed tomography (CT), CT angiography, high-resolution MRI, and conventional spinal angiography for radiotherapy planning. The mean target volume was 4.05 cc. The prescribed dose was 21 Gy in three fractions on consecutive days. No special immobilization was done during treatment. Continuous image guidance of the treated area was done using the specialized spine tracking software. Follow-up was done by yearly clinical examination and high-resolution spine MRI after SRS.
  
  
  RESULTS
  Mean follow-up was 36 months. Follow-up MRI revealed absence of flow voids, suggesting complete obliteration of the AVM in two patients, with significant improvement in neurologic and functional symptoms. The third patient did not show any clinical improvement or deterioration. There was no incidence of hemorrhage after SRS in any patient and the treatment was well tolerated without any significant complications.
  
  
  CONCLUSIONS
  Stereotactic radiosurgery for intramedullary spinal AVMs appears to be well tolerated and effective in selected cases.
authors.affiliation: Department of Radiation Oncology, Apollo Speciality Cancer Hospitals, 320, Anna Salai, Chennai 600032, India. Electronic address: mahadev62@gmail.com.
authors.forename: Mahadev
authors.initials: M
authors.lastname: Potharaju
authors.affiliation: Department of Neurosurgery, Apollo Speciality Cancer Hospitals, 320, Anna Salai, Chennai 600032, India.
authors.forename: Reginald
authors.initials: R
authors.lastname: John
authors.affiliation: Department of Medical Physics, Apollo Speciality Cancer Hospitals, 320, Anna Salai, Chennai 600032, India.
authors.forename: Murali
authors.initials: M
authors.lastname: Venkataraman
authors.affiliation: Department of Medical Physics, Apollo Speciality Cancer Hospitals, 320, Anna Salai, Chennai 600032, India.
authors.forename: Kurup
authors.initials: K
authors.lastname: Gopalakrishna
authors.affiliation: Department of Radiation Oncology, Apollo Speciality Cancer Hospitals, 320, Anna Salai, Chennai 600032, India.
authors.forename: Balaji
authors.initials: B
authors.lastname: Subramanian
mesh_terms: D000328:Adult; D001165:Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000601:surgery*; D004621:Embolization, Therapeutic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016634:Radiosurgery / Q000379:methods*; D019233:Retreatment; D012189:Retrospective Studies; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000601:surgery*; D017211:Treatment Failure; D016896:Treatment Outcome
keywords: Cyberknife; Embolization; Intramedullary spinal cord arteriovenous malformation; Microsurgery; Spinal angiogram; Stereotactic radiosurgery