Central Axis Dose Distribution With Photon Beams Flashcards
1
Q
An increase in the absorbed dose as the beam interacts with the surface of a medium, reaching a max. absorbed dose at a certain depth.
A
Electron build-up
2
Q
Energies below 400 kVp produce..
A
No dose build-up
3
Q
Maximum absorbed dose at certain depth.
A
Dmax
4
Q
The depth where the maximum dose occurs.
A
dm
5
Q
The distance between the surface and the dm.
A
Build-up region
6
Q
Because of electron build-up, the skin is spared from receiving the maximum dose.
A
Skin-sparing effect
7
Q
The ration expressed as a percentage of the dose at any depth (Dd) along the central axis of the beam to the dose at a reference point (Dmax)
A
Perecentage Depth Dose
8
Q
Applicable for SSD set-up
A
Perecentage Depth Dose
9
Q
Dose distribution date are usually measured in…
A
Water phantom
