title: The option of Linac-based radiosurgery in a Gamma Knife radiosurgery center.
abstract: OBJECTIVE
  Due to the fundamental differences in treatment delivery, linear-accelerator-based radiosurgery can be complementary to Gamma Knife (GK) for intracranial lesions. We reviewed the effect of adding GK to an existing linear accelerator (Linac)-based radiosurgery practice and analyzed case selections for the two modalities.
  
  
  METHODS
  UC Davis Medical Center installed a Leksell Gamma Knife Model C in October 2003 to supplement an established Linac-based radiosurgery program. Radiosurgery indications for the 15 months before and after installation were compared.
  
  
  RESULTS
  Radiosurgery cases expanded by twofold from 68 patients before GK installation to 139 after, with 106 treated by GK and 33 by Linac. Besides a major increase for trigeminal neuralgia and a general growth for acoustic neuroma, meningioma and brain metastases, case numbers for glioma and arteriovenous malformation (AVM) remained stable. Considering case selections for Linac, glioma decreased from 28 to 18%, while meningioma and metastases increased from 9 to 21% and 38-46%, respectively. The Linac patients receiving fractionated treatment also increased from 37 to 61%.
  
  
  CONCLUSIONS
  While the majority of patients were treated with GK, a significant proportion was judged to be suited for Linac treatment. This latter group included particularly patients who benefit from fractionated therapy.
authors.affiliation: Department of Radiation Oncology, University of California, Davis Health System, Sacramento, CA, United States. robin.stern@ucdmc.ucdavis.edu
authors.forename: Robin L
authors.initials: RL
authors.lastname: Stern
authors.forename: Julian R
authors.initials: JR
authors.lastname: Perks
authors.forename: Conrad T
authors.initials: CT
authors.lastname: Pappas
authors.forename: James E
authors.initials: JE
authors.lastname: Boggan
authors.forename: Allan Y
authors.initials: AY
authors.lastname: Chen
mesh_terms: D001932:Brain Neoplasms / Q000556:secondary / Q000601:surgery*; D002140:California; D005500:Follow-Up Studies; D006801:Humans; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000473:pathology / Q000601:surgery*; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery; D016522:Oncology Service, Hospital / Q000458:organization & administration; D010315:Particle Accelerators; D018787:Radiation Oncology / Q000458:organization & administration; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D013503:Surgery Department, Hospital / Q000458:organization & administration; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000473:pathology / Q000601:surgery