title: Treatment Strategy of Intracranial Hemangiopericytoma.
abstract: BACKGROUND
  Recent studies suggest aggressive management combining a grossly total resection (GTR) with adjuvant radiotherapy (RT) as a treatment of choice for intracranial hemangiopericytoma (HPC). However, in these papers, the definitions of complete or GTR are equivocal. In the present study, we reviewed the relevant cases from our experience focused on the clinical efficacy of surgical grading of resection, and analyzed the optimal treatment strategies as well.
  
  
  METHODS
  From January 1995 through December 2014, 17 patients treated for intracranial HPC were included in this study. We analyzed clinical presentation, radiologic appearance, pathologic diagnosis, extent of resection, and follow-up outcomes.
  
  
  RESULTS
  A total of 26 operations were performed including 9 recurrent intracranial HPCs. Every tumor was single and had no evidence of metastasis. Most common area of tumor was parasagittal (8 patients, 47.1%), which is adjoined to superior sagittal sinus. For the initial operation, GTR was performed in 16 cases (61.5%), partial resection (PR) in 8 cases (30.8%), and an endoscopic biopsy in 2 patients (7.7%). In Simpson grading system, grade 1 was done in 2 patients (7.7%), grade 2 in 11 patients (42.3%) and grade 3 in 3 patients (11.5%). Postoperative RT was delivered in 16 patients (94.1%) regardless of the extent of resection. The median 57.57 Gy (range, 50-60 Gy) was delivered in median 33 fractions (range, 30-40). The extent of resection (conventional classification and Simpson grading system) and adjuvant RT were significantly associated with recurrence-free survival.
  
  
  CONCLUSIONS
  Surgical resection of intracranial HPC, in an attempt to reach Simpson grade 1 removal, is necessary for better outcome. Adjuvant RT should be done as recommended before, to prevent recurrence, regardless of surgical resection and pathological diagnosis.
authors.affiliation: Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Young-Joo
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sin-Soo
authors.initials: SS
authors.lastname: Jeun
keywords: Adjuvant radiotherapy; Brain neoplasms; Hemangiopericytoma; Radiation; Recurrence