1522-1523 / 2239
(
)
(
)
(
)
( )
(
)
ref
ref
ref ref
Meas
1
0
; ,
,
D A x y z M
M
Ψ
−
=
(
)
(
)
( )
(
)
0
0
1
0
; ,
, ;
;
1
;
D A x y
D A x y
z
z
M
A
M
b
Ψ
Ψ
−
=
⋅ +
Including monitor signal
M
b
caused by backscatter depending on collimator setting
M
0
M
b
Monitor chamber
mon
z
coll
z
ref
ref
ref ref
0
ref
Calc
0
; ,
,
1
D A x y z
b A
Ψ
⋅ +
( )
(
)
0
0
( ) 1
b
M M M A
b A M
= +
= +
( )
2
mon
back
2
coll
z
b A k F
z
=
Empirical factor from
S
c
measurements
(
)
(
)
all fields
;prescription conditions
i
i
D A
w
=
∑
Plan with dose weighted fields and prescribed dose
D
pres
:
Includes head scatter
and phantom scatter
(
)
3
2
Irradiated
coll
mon
collimator
area
cos
d
F
A
z z
θ
π
=
−
∫∫
(
)
presc
; at prescription point/conditions from field
i
i
i
D w
M
D A
i
M
⋅
=
=1
;prescription conditions
i
i
D A