Technical note: the effect of the 4-mm-collimator output factor on gamma knife dose distributions.
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.
Gibbons
John P
JP
Gamma Knife Center of the Carolinas, Columbia, South Carolina 29203, USA. john.gibbons@palmettohealth.org
Mihailidis
Dimitris
D
Worthington
Curtis
C
Alkhatib
Hassaan
H
Boulware
Raleigh
R
Clark
Robert
R
Dial
Burke
B
Neglia
William
W
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