title: Risk of malignancy after gamma knife stereotactic radiosurgery.
abstract: OBJECTIVE
  To assess the risk of radiosurgery to cause malignant transformation in benign tumors or to induce new malignancies.
  
  
  METHODS
  A retrospective cohort study comparing the Sheffield, England, radiosurgery patient database with national mortality and cancer registries. This data set comprises approximately 5000 patients and 30,000 patient-years of follow-up, with more than 1200 patients having a follow-up period longer than 10 years.
  
  
  RESULTS
  In this material, a single new astrocytoma was diagnosed, whereas, based on national incidence figures, 2.47 cases would have been predicted.
  
  
  CONCLUSIONS
  No increased risk of malignancy was detected in this series, supporting the safety of radiosurgery. Pragmatically, in advising patients, the risks of malignancy would seem small, particularly if such risks are considered in the context of the other risks faced by patients with intracranial pathologies requiring radiosurgical treatments.
authors.affiliation: National Centre for Stereotactic Radiosurgery, Royal Hallamshire Hospital, Sheffield, England, UK. Jeremy.Rowe@sth.nhs.uk
authors.forename: Jeremy
authors.initials: J
authors.lastname: Rowe
authors.forename: Alison
authors.initials: A
authors.lastname: Grainger
authors.forename: Lee
authors.initials: L
authors.lastname: Walton
authors.forename: Paul
authors.initials: P
authors.lastname: Silcocks
authors.forename: Matthias
authors.initials: M
authors.lastname: Radatz
authors.forename: Andras
authors.initials: A
authors.lastname: Kemeny
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009366:Neoplasm Seeding; D016634:Radiosurgery / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate