title: Gamma knife radiosurgery for treatment resistant choroid plexus papillomas.
abstract: OBJECTIVE
  To report the results of gamma knife radiosurgery (GKR) for treatment resistant choroid plexus papillomas.
  
  
  METHODS
  Six patients (median age 55 years; range 29-75) with residual (n = 2) or recurrent (n = 4) choroid plexus papillomas underwent GKR. All failed prior surgery and one failed prior proton beam radiation therapy. These six patients had a total of 11 locally or distant recurrent intracranial tumors. The median and mean tumor volumes were 2.7 and 3.9 cc (range, 0.23-21.1). A median margin dose of 12.0 Gy (range, 11.5-15) was prescribed to the tumor margin.
  
  
  RESULTS
  The progression-free periods varied from 7 to 108 months (mean: 36.9). Four tumors were stable after GKR but seven showed progression. Four recurrent tumors in two patients were managed with repeat radiosurgery and three were observed. At the second GKR, the tumor volume varied from 1.3 to 12.4 cc, and the marginal radiation dose varied from 11 to 14 Gy. The overall survival after the first GKR varied from 15 to 120 months. Four patients were alive at the end of the study period.
  
  
  CONCLUSIONS
  Radiosurgery represents an additional management strategy for patients who progress despite surgical removal. It may especially be useful for patients with small deep seated residual choroid plexus papillomas, and for tumors that recur at a site distant from their origin.
authors.affiliation: Department of Neurological Surgery, Center for Image-Guided Neurosurgery, Medical Center-Presbyterian, University of Pittsburgh, 200 Lothrop Street, Suite B-400, Pittsburgh, PA 15213, USA.
authors.forename: In-Young
authors.initials: IY
authors.lastname: Kim
authors.forename: Ajay
authors.initials: A
authors.lastname: Niranjan
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D020288:Papilloma, Choroid Plexus / Q000601:surgery*; D016634:Radiosurgery