title: A comparison of the gamma knife model C and the automatic positioning system with Leksell model B.
abstract: OBJECTIVE
  The authors sought to compare the quality of treatment planning, radiation protection, and the time taken for treatment in the Leksell gamma knife model B with that using the model C Automatic Positioning System (APS).
  
  
  METHODS
  Data were obtained in 463 patients treated with the B model and 518 patients treated with the C model. Data were analyzed in patients in whom the following diagnoses had been made: vestibular schwannoma, pituitary adenoma, meningioma, solitary metastasis, and other benign and malignant solitary tumors. Patients with arteriovenous malformations, ocular lesions, and functional diagnoses were excluded from this study.
  
  
  CONCLUSIONS
  With the C model there was a better conformity for most treated targets, such as vestibular schwannomas (p = 0.005) and meningiomas (p = 0.015). The level of radiation exposures to personnel was significantly decreased when using the model C (p < 0.001). There was no significant difference in radiation exposure of extracranial structures for the same number of shots in patients treated by both models. The mean time saved using the C model with the APS was 41 minutes per treatment. It would seem that the gamma knife model C permits better dose conformity, shorter treatment times, and less radiation exposure to personnel.
authors.affiliation: Departments of Stereotactic and Radiation Neurosurgery, and Medical Physics, Na Homolce Hospital, Prague, Czech Republic. daniela.tlachacova@homolka.cz
authors.forename: Daniela
authors.initials: D
authors.lastname: Tlachacova
authors.forename: Michal
authors.initials: M
authors.lastname: Schmitt
authors.forename: Josef
authors.initials: J
authors.lastname: Novotny
authors.forename: Josef
authors.initials: J
authors.lastname: Novotny
authors.forename: Mustafa
authors.initials: M
authors.lastname: Majali
authors.forename: Roman
authors.initials: R
authors.lastname: Liscak
mesh_terms: D000236:Adenoma / Q000601:surgery*; D001331:Automation / Q000295:instrumentation*; D001932:Brain Neoplasms / Q000556:secondary*; D004867:Equipment Design; D006282:Health Personnel; D006801:Humans; D008577:Meningeal Neoplasms / Q000601:surgery*; D008579:Meningioma / Q000601:surgery*; D009464:Neuroma, Acoustic / Q000601:surgery*; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects / Q000706:statistics & numerical data; D010911:Pituitary Neoplasms / Q000601:surgery*; D018788:Radioactive Hazard Release / Q000706:statistics & numerical data; D016634:Radiosurgery / Q000295:instrumentation*