title: Gamma knife radiosurgery for central neurocytoma: primary and secondary treatment.
abstract: BACKGROUND
  Little is known about long-term results of gamma knife (GK) stereotactic radiosurgery (SRS) as a primary or a secondary postoperative therapy for central neurocytomas (CNs). The authors retrospectively reviewed long-term outcomes of 13 patients with CN treated with GK SRS.
  
  
  METHODS
  Thirteen patients were treated with GK SRS as a primary (6 patients) or a secondary postoperative therapy (7 patients). Follow-up clinical status and brain magnetic resonance imaging (MRI) were thoroughly analyzed. The functional status of patients was assessed with the Karnofsky Performance Scale during follow-up.
  
  
  RESULTS
  The median follow-up period for clinical status and imaging studies was 61 months (range, 6 months to 96 months). Tumors decreased in 5 patients who received GK SRS as a primary treatment. However, the tumor recurred in 2 patients treated with a secondary GK SRS after surgery from the residual tumor bed that was not covered by the GK SRS. Parenchymal changes and secondary malignancies were not found in follow-up MRIs of all 13 patients. The Karnofsky Performance Scale score of all patients, except for 1 patient who suffered from an unrelated anteriorly communicating arterial aneurysmal rupture, did not change after GK SRS.
  
  
  CONCLUSIONS
  GK SRS may be useful as a primary or a secondary postoperative therapy for the treatment of CN. However, more attention should be paid to residual or recurrent CN during treatment, and regular long-term follow-up MRI should be mandatory to validate the procedure.
authors.affiliation: Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Chae-Yong
authors.initials: CY
authors.lastname: Kim
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Paek
authors.forename: Sang Soon
authors.initials: SS
authors.lastname: Jeong
authors.forename: Hyun-Tai
authors.initials: HT
authors.lastname: Chung
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Han
authors.forename: Chul-Kee
authors.initials: CK
authors.lastname: Park
authors.forename: Hee-Won
authors.initials: HW
authors.lastname: Jung
authors.forename: Dong Gyu
authors.initials: DG
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018306:Neurocytoma / Q000601:surgery*; D016634:Radiosurgery; D012189:Retrospective Studies; D016896:Treatment Outcome