Gamma knife radiosurgery for arteriovenous malformations: long-term follow-up results focusing on complications occurring more than 5 years after irradiation

Neurosurgery. 1996 May;38(5):906-14. doi: 10.1097/00006123-199605000-00010.


The detailed long-term follow-up results of 40 patients treated for cerebral arteriovenous malformations with gamma knife radiosurgery are presented, with special reference to postradiosurgical complications that can develop many years after irradiation. The follow-up period after radiosurgery was 54 to 205 months, excluding one mortality, with a mean and a median of 106 and 97 months, respectively. One patient (2.5%) has, to date, refused all neuroimaging follow-up examinations. Complete nidus obliteration was angiographically confirmed in 26 patients (65%) between 1 and 5 years after radiosurgery. In the remaining 13 patients (32.5%), although significant shrinkage of each nidus was angiographically demonstrated, complete obliteration was not attained during a 3- to 7-year period of follow-up after radiosurgery. Among these 13 patients, 1 underwent surgical extirpation of the nidus and 5 underwent second courses of gamma knife radiosurgery between 3 and 6 years after initial treatment; in 3 of the 5 patients, complete nidus obliteration was angiographically confirmed between 1 and 3 years after the second course of radiosurgery. There were no radiation- or arteriovenous malformation-related mortalities. However, we did experience one angiography-related mortality. We also experienced one morbidity (probably caused by hemorrhagic stroke), which developed 5 years after 2-year postradiosurgical angiography had demonstrated complete obliteration, and three radiation-related morbidities, two of which (hemiparkinsonian syndrome and visual field disturbances caused by delayed cyst formation) occurred 5.5 and 7 years, respectively, after irradiation. Furthermore, we observed another two patients who, although asymptomatic to date, showed delayed cyst formation on magnetic resonance imaging 5 and 10 years after irradiation, respectively. In total, 3 (23%) of 13 patients who underwent computed tomography and/or magnetic resonance imaging more than 5 years after radiosurgery showed delayed cyst formation. In conclusion, long-term follow-up, particularly with the use of neuroimaging techniques, is necessary even after the treatment goal has been achieved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brain / radiation effects
  • Cerebral Angiography
  • Cerebral Hemorrhage / diagnosis
  • Cerebral Hemorrhage / etiology
  • Cerebral Hemorrhage / surgery
  • Cerebrovascular Disorders / diagnosis
  • Cerebrovascular Disorders / etiology
  • Cerebrovascular Disorders / surgery
  • Child
  • Cysts / diagnosis
  • Cysts / etiology
  • Cysts / surgery
  • Female
  • Follow-Up Studies
  • Humans
  • Intracranial Arteriovenous Malformations / diagnosis
  • Intracranial Arteriovenous Malformations / surgery*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Postoperative Complications / diagnosis
  • Postoperative Complications / etiology*
  • Postoperative Complications / surgery
  • Radiation Injuries / diagnosis
  • Radiation Injuries / etiology
  • Radiation Injuries / surgery
  • Radiosurgery*
  • Reoperation
  • Tomography, X-Ray Computed