title: The role for adjuvant radiotherapy in the treatment of hemangiopericytoma: a Surveillance, Epidemiology, and End Results analysis.
abstract: OBJECTIVE
  Central nervous system (CNS) hemangiopericytomas are relatively uncommon and unique among CNS tumors as they can originate from or develop metastases outside of the CNS. Significant difference of opinion exists in the management of these lesions, as current treatment paradigms are based on limited clinical experience and single-institution series. Given these limitations and the absence of prospective clinical trials within the literature, nationwide registries have the potential to provide unique insight into the efficacy of various therapies.
  
  
  METHODS
  The authors queried the Surveillance Epidemiology and End Results (SEER) database to investigate the clinical behavior and prognostic factors for hemangiopericytomas originating within the CNS during the years 2000-2009. The SEER survival data were adjusted for demographic factors including age, sex, and race. Univariate and multivariate analyses were performed to identify characteristics associated with overall survival.
  
  
  RESULTS
  The authors identified 227 patients with a diagnosis of CNS hemangiopericytoma. The median length of follow-up was 34 months (interquartile range 11-63 months). Median survival was not reached, but the 5-year survival rate was 83%. Univariate analysis showed that age and radiation therapy were significantly associated with survival. Moreover, young age and supratentorial location were significantly associated with survival on multivariate analysis. Most importantly, multivariate analysis using the Cox proportional hazards model showed a statistically significant survival benefit for patients treated with gross-total resection (GTR) in combination with adjuvant radiation treatment (HR 0.31 [95% CI 0.01-0.95], p = 0.04), an effect not appreciated with GTR alone.
  
  
  CONCLUSIONS
  The authors describe the epidemiology of CNS hemangiopericytomas in a large, national cancer database, evaluating the effectiveness of various treatment paradigms used in clinical practice. In this study, an overall survival benefit was found when GTR was accomplished and combined with radiation therapy. This finding has not been appreciated in previous series of patients with CNS hemangiopericytoma and warrants future investigations into the role of upfront adjuvant radiation therapy.
authors.affiliation: Department of Neurological Surgery, Neurological Institute of New York, College of Physicians and Surgeons;
authors.forename: Adam M
authors.initials: AM
authors.lastname: Sonabend
authors.forename: Brad E
authors.initials: BE
authors.lastname: Zacharia
authors.forename: Hannah
authors.initials: H
authors.lastname: Goldstein
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Bruce
authors.forename: Dawn
authors.initials: D
authors.lastname: Hershman
authors.forename: Alfred I
authors.initials: AI
authors.lastname: Neugut
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Bruce
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016543:Central Nervous System Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006393:Hemangiopericytoma / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D016634:Radiosurgery; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D012737:Sex Factors; D015173:Supratentorial Neoplasms / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult