title: Treatment Results of Gamma Knife Radiosurgery for Central Neurocytoma: Report of a Japanese Multi-Institutional Cooperative Study.
abstract: OBJECTIVE
  Central neurocytoma (CN) is a rare benign neuronal tumor, and a limited number of reports have described the usefulness of radiosurgery for a relatively large group of patients. We evaluated the effectiveness and outcomes of Gamma Knife radiosurgery (GKS) for CN in a Japanese multi-institutional study.
  
  
  METHODS
  We performed retrospective analysis of 36 patients with CN who were treated with GKS in 12 institutes in Japan. All patients underwent surgery before GKS. The median tumor volume at GKS was 4.9 mL (range, 0.07-23.4 mL), and the median radiation dose prescribed to the tumor margin was 15 Gy (range, 10-20 Gy). The median follow-up period was 54.5 months (range, 3-180 months).
  
  
  RESULTS
  The local tumor progression-free survival rates at 5 and 10 years were 94% and 86%, respectively. Three patients developed distant dissemination 16-90 months later. Overall progression-free survival was unrelated to the prescribed dose (<15 Gy vs. ≥15 Gy, P = 0.62), tumor size (<6 mL vs. ≥6 mL, P = 0.46), gender (P = 0.36), age (<30 vs. ≥30 years, P = 0.37), target of GKS (residual vs. recurrence, P = 0.90), and type of enhancement (homogeneous vs. inhomogeneous, P = 0.19). Two permanent complications occurred with 1 intratumoral hemorrhage and 1 radiation injury.
  
  
  CONCLUSIONS
  GKS is effective for CN because of its high rate of long-term local tumor control. GKS may have a potential role as a primary treatment for asymptomatic, relatively small tumors in the absence of hydrocephalus without surgical resection.
authors.affiliation: Department of Neurosurgery, Osaka City General Hospital, Osaka, Japan. Electronic address: kyama115@med.osaka-cu.ac.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamanaka
authors.affiliation: Department of Neurosurgery, Osaka City General Hospital, Osaka, Japan.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Iwai
authors.affiliation: Department of Neurosurgery, Yokohama Rosai Hospital, Yokohama, Kanagawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shuto
authors.affiliation: Department of Neurosurgery, Komaki City Hospital, Komaki, Aichi, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kida
authors.affiliation: Department of Neurosurgery, Kitanihon Neurosurgical Hospital, Gosen, Niigata, Japan.
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Neurosurgery, Shin-Suma Hospital, Kobe, Hyogo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Neurosurgery, Koto Memorial Hospital, Higashioumi, Shiga, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Hirai
authors.affiliation: Department of Neurosurgery, Shiokawa Hospital, Suzuka, Mie, Japan.
authors.forename: Rentaro
authors.initials: R
authors.lastname: Hori
authors.affiliation: Department of Neurosurgery, Koyo Hospital, Wakayama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kubo
authors.affiliation: Department of Neurosurgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Hisae
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Neurosurgery, Chiba Cardiovascular Center, Ichihara, Chiba, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nagano
authors.affiliation: Tsukiji Neurological Clinic, Tokyo Gamma Unit Center, Tokyo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Serizawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000517:prevention & control; D018306:Neurocytoma / Q000401:mortality* / Q000532:radiotherapy*; D015995:Prevalence; D011832:Radiation Injuries / Q000401:mortality / Q000517:prevention & control; D016634:Radiosurgery / Q000401:mortality* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
keywords: Central neurocytoma; Gamma Knife radiosurgery; Stereotactic radiosurgery; Tumor control