Dose Course 2018_Flipping book

Dose per MU formalisms: factor-based dose calculations

Isocentric formalism: dose per meterset NOT at isocentre (on CAX)

Scaling energy fluence from that at isocentre to that at the calculation point not at SAD

2

(

)

(

)

SSD dsD

d cD

; ,

,

SAD

  

  

( ) ( eqsq  p

)

(

)

d

ref

ref

 sS cS

 d s TPR

=



,

d

c

eqsq ,

eqsq d,

M

M

d SSD

+

On the assumption that phantom scatter ratios are independent of SSD The field size used is that at the calculation point