Dose Course 2018_Flipping book

Dose per MU formalisms: model-based dose calculations

Including monitor signal M b

caused by backscatter as a function of collimator aperture, the

formalism is:

(

)

(

)

; , ; D A x y z D A x y ; , ;

z



) 1 −

(

( )

0

b A

=

1  +

M

M



0

0

calibration factor





(

)

M z y x AD

;

,

,



ref

ref

ref

ref

o

meas

=





( ) ref − +  )

1

(

)

(

M

1 Ab z y x AD

;

,

,

o

ref

ref

ref

ref

o

calc

Note: Different implementations in common TPSs described in the next lecture)