Scatter dose for wedged fields.
The behaviour of scatter dose in 4 and 8 MV wedged x-ray beams has been studied by calculating scatter-to-primary dose ratios (SPR) and comparing these with SPR for non-wedged beams. On the central axis the SPR for wedged and non-wedged beams differ only by a few per cent, a difference which increases slightly with wedge angle and field size. In other points within the field the differences are larger but generally less than 3% of the total dose on the central axis at the same depth. The product rule for points that do not lie in a principal plane is valid within the same limits as for non-wedged beams.
Brown
L H
LH
Joint Center for Radiation Therapy, Harvard Medical School, Boston, MA 02115.
Siddon
R L
RL
Bjärngard
B E
BE
D003037:Cobalt Radioisotopes; D011827:Radiation; D011878:Radiotherapy / Q000592:standards*; D012542:Scattering, Radiation; D014965:X-Rays
D003037:Cobalt Radioisotopes