Dose Course 2018_Flipping book

Dose per MU formalisms: factor-based dose calculations

• Step 1: account for differences in dose at the calculation point due to changes in scatter conditions in the head of the linac • Step 2: account for differences in phantom scatter due to the change in field size (amount of phantom irradiated) • Step 3 : account for differences in phantom scatter due to the change of depth

Isocentric linac reference normalisation geometry

SAD

d

SAD

ref

SAD

c

d

ref

d

d

c

d

c

ref

ref

c

c

c

ref

d

ref

c

c

ref

c

ref