title: Analysis of repeat stereotactic radiosurgery for progressive primary and metastatic CNS tumors.
abstract: OBJECTIVE
  To identify and evaluate the pretreatment and patient factors that would predict for complications after repeat radiosurgery.
  
  
  METHODS
  The data from 26 patients who underwent re-irradiation with Gamma Knife surgery after a previous procedure in the same or subjacent location were available for evaluation. The range of follow-up was 1-45 months (mean 10). The mean minimal and maximal initial dose and volume for all 26 patients was 16.2 Gy (range 12-22), 31.0 Gy (range 22.2-40.0), and 12.4 cm(3) (range 1.20-70.84), respectively. The mean marginal and maximal repeated radiosurgery dose and volume for all 26 patients was 14.9 Gy (range 12-22.5), 29.7 Gy (range 18.0-45.0) and 12.8 cm(3) (range 1.10-39.20), respectively.
  
  
  RESULTS
  Tumor control was significantly better statistically (p = 0.0129) for benign tumors (6 of 6, 100% actuarial rate at 4 years) compared with malignant tumors (7 of 20, 35% actuarial rate at 3 years, 3 of 4 metastatic tumors and 2 of 10 primary malignant gliomas). The retreatment volume for radiosurgery correlated significantly with the probability of neurologic decline (any cause) (p = 0.0181).
  
  
  CONCLUSIONS
  Repeat radiosurgery can be performed for recurrent tumors with minimal central nervous system toxicity, especially for benign tumors, with reasonable tumor control.
authors.affiliation: Department of Radiation Oncology, Center for Image-Guided Neurosurgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: Dwight E
authors.initials: DE
authors.lastname: Heron
authors.forename: Douglas
authors.initials: D
authors.lastname: Kondziolka
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000556:secondary / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000009:adverse effects*; D012044:Regression Analysis; D012086:Reoperation; D012189:Retrospective Studies