title: Precision radiotherapy for hemangiopericytomas of the central nervous system.
abstract: BACKGROUND
  Radiotherapy (RT) plays a major role in the management of hemangiopericytomas (HAP). The present analysis evaluates the role of precision RT in the management of HAP of the central nervous system (CNS) and represents one of the largest series of HAP treated with RT that can be found in the literature.
  
  
  METHODS
  Of 37 consecutive patients with histologically confirmed HAP who were treated at the institution between 1984 and 2004, the majority, 25 tumors, was localized within the skull base (n = 25) and 4 tumors were localized at the spine. In 25 patients, high-precision RT was delivered as fractionated stereotactic RT or intensity modulated RT. Median age at primary diagnosis was 40.5 years (range, 10-77 yrs). After primary diagnosis, surgical resection was performed in 23 patients. A median total dose of 54 Gy was delivered in a fractionation of 5 x 1.8-2 Gy per week. The median planning target volume was 58.2 mL (range, 10-412 mL). The median follow-up time was 34 months (range, 3-166 mos).
  
  
  RESULTS
  Radiotherapy was well tolerated by all patients. Seventeen patients of this series remain alive. Overall survival rates at 5 and 10 years are 100% and 64%, respectively. Actuarial survival rates after RT were 85% and 69% at 3 and 5 years, respectively. Progression-free survival after RT 80% and 61% at 3 and 5 years, respectively.
  
  
  CONCLUSIONS
  High-precision RT is an effective and safe treatment modality for patients with HAP of the CNS and the spine and achieves highly acceptable tumor control, while sparing normal tissue.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany. Stephanie.combs@med.uni-heidelberg.de
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
authors.forename: Christoph
authors.initials: C
authors.lastname: Thilmann
authors.forename: Jurgen
authors.initials: J
authors.lastname: Debus
authors.forename: Daniela
authors.initials: D
authors.lastname: Schulz-Ertner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016543:Central Nervous System Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D006393:Hemangiopericytoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D011878:Radiotherapy / Q000379:methods*; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D016019:Survival Analysis; D013997:Time Factors