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Dose per MU formalisms:
factor-based dose calculations
Isocentric linac
reference
normalisation
geometry
• 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
c
ref
d
ref
SAD
c
SAD
d
d
ref
c
SAD
c
ref
c
c
ref
c
ref
c
c
d
d
ref
d
ref