An electron density calibration phantom for CT-based treatment planning computers.
In order to correct for tissue heterogeneities on a voxel-by-voxel basis during CT-based treatment planning, the relationship between the correction factor (CF) and the CT number in Hounsfield units (HU) for the scanner in use must be established. Since the relationship between CF and electron density (rho e) of various materials is well documented, the rho e vs HU is required for direct computation of the correction factors by treatment planning computers. A CT phantom with 18 different tissue substitutes has been used to establish the rho e vs HU relationship. A description of the phantom and its contents is given and the calibration of the CT function of the planning computer is discussed.
Constantinou
C
C
Department of Radiation Oncology, Brockton Hospital, Massachusetts 02402.
Harrington
J C
JC
DeWerd
L A
LA
D002138:Calibration; D006801:Humans; D008961:Models, Structural; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*