title: The risk of malignancy anywhere in the body after linear accelerator (LINAC) stereotactic radiosurgery.
abstract: BACKGROUND
  Despite the conformity of stereotactic radiosurgery (SRS) treatment, there are concerns about the risk of malignancy.
  
  
  OBJECTIVE
  We compared the number of cancer cases observed after treatment in a group of SRS patients to the number of cancer cases that would be expected in an age- and gender-matched group.
  
  
  METHODS
  We collected data from the University of Florida SRS database for patients treated for meningiomas, intracranial schwannomas, arteriovenous malformations (AVMs), trigeminal neuralgia, pituitary adenomas, cavernous angiomas, and metastases. We used the Florida Cancer Data System (FCDS) to determine the actual cancer rates for SRS-treated patients, and we compared these to the cancer rates in similar groups of non-SRS-treated patients based on rates available from the SEER (surveillance epidemiology and end results) database.
  
  
  RESULTS
  A total of 2,369 patients were analyzed. Of these, 862 were patients with metastases who were analyzed only to ensure the sensitivity of using the FCDS to determine malignancy rates. The results for patients with more than 5 years of follow-up are reported. Without the metastases patients, a total of 627 patients had more than 5 years of follow-up data. Follow-up in patient-years was 1,711 for the meningioma patients, 1,851 for the schwannoma patients, 1,407 for the AVM patients and 338 for patients with a diagnosis of 'other'. The observed cancer rate in the meningioma patients was 3.96% compared to the expected rate of 10% (binomial 95% confidence interval, CI = 1.85-7.94). The observed cancer rate in the schwannoma patients was 4.93% compared to the expected rate of 12.5% (95% CI = 2.61-8.89). The observed cancer rate in the AVM patients was 3.64% compared to the expected rate of 4.43% (95% CI = 1.49-8.10). The observed cancer rate in patients treated for other diagnoses (e.g. pituitary adenoma or trigeminal neuralgia) was 0% compared to the expected rate of 6.36% (95% CI = 0-11.7).
  
  
  CONCLUSIONS
  In a large population of SRS-treated patients, there was no increased risk of malignancy compared to the general population.
authors.affiliation: Department of Neurosurgery, University of Florida, Gainesville, Fla., USA.
authors.forename: Maryam
authors.initials: M
authors.lastname: Rahman
authors.forename: Dan
authors.initials: D
authors.lastname: Neal
authors.forename: William
authors.initials: W
authors.lastname: Baruch
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Bova
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Frentzen
authors.forename: William A
authors.initials: WA
authors.lastname: Friedman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000601:surgery*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D010315:Particle Accelerators; D016634:Radiosurgery / Q000009:adverse effects* / Q000295:instrumentation; D012189:Retrospective Studies; D012306:Risk; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000601:surgery*; D055815:Young Adult