title: Technical note: the effect of the 4-mm-collimator output factor on gamma knife dose distributions.
abstract: We present results of investigations of the clinical significance of variations in the value of the 4-mm-collimator output factor, OF(4/18). Changes in treatment volume, dose-volume histograms (DVHs), and isodose distributions were studied, by varying OF(4/18) up to 20%. The variations were performed on a sample of clinical patient treatment plans for which the 4 mm collimator was used. Although smaller effects are noted for the prescription isodose line, greater dosimetric changes occur for higher dose regions within the target.
authors: Gamma Knife Center of the Carolinas, Columbia, South Carolina 29203, USA. john.gibbons@palmettohealth.org
authors: John P
authors: JP
authors: Gibbons
authors: Dimitris
authors: D
authors: Mihailidis
authors: Curtis
authors: C
authors: Worthington
authors: Hassaan
authors: H
authors: Alkhatib
authors: Raleigh
authors: R
authors: Boulware
authors: Robert
authors: R
authors: Clark
authors: Burke
authors: B
authors: Dial
authors: William
authors: W
authors: Neglia
mesh_terms: D001165:Arteriovenous Malformations / Q000601:surgery; D001254:Astrocytoma / Q000601:surgery; D016543:Central Nervous System Neoplasms / Q000601:surgery; D006801:Humans; D008577:Meningeal Neoplasms / Q000601:surgery; D008579:Meningioma / Q000601:surgery; D009464:Neuroma, Acoustic / Q000601:surgery; D016634:Radiosurgery / Q000295:instrumentation* / Q000639:trends*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000639:trends