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Dose calculation – AAPM-TG43: The Radial Dose Function g(r):
g(r):
The radial dose function that considers the distance dependence
of absorption and scatter of the photon rays in the water medium
along the transversal axis, that is the y-axis or equivalently for
θ = 90
0
.
g(r) is a dimensionless quantity.
It is always g(r=1cm) = 1.00.
g(r) depends in general on source
design and radionuclide.
T
he “Inverse-Square-Law” is
filtered out !!!
g(r)
!