Advanced Physics for Brachytherapy 2018

Brachytherapy Q is source/position dependent…

rel

may be considerable

f

k rel

,

bq

(especially for low E) BUT

photon fluence vs distance per starting particle emitted from a point 125Ι (top) and 192Ir (bottom) source centered in a 15cm radius water phantom, multiplied by distance squared

They are source dependent (source materials) and position dependent (source spectra vary with distance, angle)

•

•

especially for high Z detectors

Figure from: Papagiannis, Pantelis, Karaiskos, Br J Radiol (2014) 87: 20140163