title: The role of radiosurgery for hemangiopericytomas.
abstract: OBJECTIVE
  Hemangiopericytomas represent a small subset of meningeal tumors. Despite their relatively uncommon nature, they are aggressive tumors known for recurrence. Resection is the standard treatment in most, although regrowth and metastases are common even after resection. The authors evaluate the role of stereotactic radiosurgery in the treatment of recurrent hemangiopericytomas.
  
  
  METHODS
  In a review of the Stanford radiosurgery patient database between 1989 and 2002, the authors found eight patients with recurrent hemangiopericytoma who underwent stereotactic radiosurgery. The mean age of this population was 45.1 years (range 24-67 years). All patients had been previously treated with resection, and five patients (63%) had undergone conventional radiotherapy. The mean radiosurgery dose to the tumor margin was 20.5 Gy (range 16-24 Gy). The mean clinical and radiographic follow-up period was 44 months (range 8-77 months). Of the eight tumors treated with radiosurgery, six decreased in size and two ultimately progressed. There were no radiosurgery-related complications.
  
  
  CONCLUSIONS
  Stereotactic radiosurgery of hemangiopericytomas can result in increased tumor control and should be considered as a treatment option for patients in whom the diagnosis has been established and in whom residual tumor is demonstrated postoperatively. Close clinical and radiographic follow-up evaluation is necessary in this patient population because of the high rate of local recurrence and distant metastases.
authors.affiliation: Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305, USA. sdchang@stanford.edu
authors.forename: Steven D
authors.initials: SD
authors.lastname: Chang
authors.forename: Gordon T
authors.initials: GT
authors.lastname: Sakamoto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006393:Hemangiopericytoma / Q000000981:diagnostic imaging / Q000517:prevention & control / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000517:prevention & control / Q000601:surgery; D011859:Radiography; D016634:Radiosurgery / Q000379:methods* / Q000706:statistics & numerical data; D012189:Retrospective Studies