Advanced Brachytherapy Physics - Vienna 2016

• F ( r , θ ) is always unity for a perfect point source • F ( r , θ ) = 1 at θ 0 • F ( r , θ ) accounts for dose-rate variation over angles due to differing attenuation by source capsule, internal components, … • Must know source orientation use 2D formalism – otherwise, use the 1D formalism

slide courtesy of Luc Beaulieu