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Dose calculation – AAPM-TG43: The Geometry Function G(r,θ):
G(r,θ):
The geometry function at radial distance r and polar angle θ. It is a
dimensionless quantity.
• From a physics point of view the geometry function simply provides an
effective inverse square-law correction based upon the spatial distribution of
radioactivity within the source core.
•
It depends only on the 3D volume shape of the active core of the source
and not on the radionuclide, nor on the encapsulation!
•
It does not consider scatter and attenuation!