title: Intracranial Hemangiopericytomas : A Retrospective Study of 15 Patients with a Special Review of Recurrence.
abstract: OBJECTIVE
  Although surgical resection is used to treat meningeal hemangiopericytoma (MHPC), there is a high risk of subsequent recurrence. This study investigated factors associated with treatment outcomes and recurrence in patients who had undergone surgical resection of intracranial MHPC.
  
  
  METHODS
  Fifteen patients underwent surgical treatments performed by one senior neurosurgeon between 1997 and 2013. Clinical data, radiologic images, surgical outcomes, recurrence, and other relevant characteristics were reviewed and analyzed.
  
  
  RESULTS
  Fifteen patients were included in the analysis, 12 (80%) of whom had tumors in the supratentorial region, and 3 (20%) of whom had tumors in the infratentorial region. Complete resection was achieved in all 15 patients, and 3 (20%) patients were administered radiosurgery and conventional radiotherapy after surgery as adjuvant radiotherapy. Three patients developed recurrence, 2 of whom had not received adjuvant radiotherapy. In 1 of the patients who had not received adjuvant radiotherapy, recurrence developed at the original tumor site, 81 months after surgery. The other 2 recurrences occurred at other sites, 78 and 41 months after surgery. The 5- and 10-year overall survival rates were 88.3%, while the 5- and 10-year recurrence-free survival rates were 83% and 52%, respectively. Additionally the mean Ki-67 index differed significantly between patients who did and did not develop recurrence (43% vs. 14%; p=0.001).
  
  
  CONCLUSIONS
  Because of the high risk of MHPC recurrence, MHPC tumors should be completely resected, whenever feasible. However, even when complete resection is achieved, adjuvant radiotherapy might be necessary to prevent recurrence.
authors.affiliation: Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam, Korea.
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Noh
authors.affiliation: Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam, Korea.
authors.forename: Jae Joon
authors.initials: JJ
authors.lastname: Lim
authors.affiliation: Department of Neurosurgery, Bundang CHA Medical Center, CHA University College of Medicine, Seongnam, Korea.
authors.forename: Kyung Gi
authors.initials: KG
authors.lastname: Cho
keywords: Complete resection; Extraneural metastasis; Meningeal hemangiopericytoma; Radiation therapy; Recurrence