Dose Course 2018_Flipping book
Spectrum corrections of raytraced collision kerma and scerma for attenuated beams (wedges)
(
)
g
1
−
KERMA
(
)
mod
k
Multiply cKERMA by
(
)
, depth thickness
=
PQ
(
)
1 KERMA g −
(
)
open
SCERMA
(
)
mod
Multiply SCERMA by
( SQ depth thickness k ,
)
=
SCERMA
(
)
open
Beam quality corrections for a 1.5 cm lead attenuator
1.10
i. e.
1.05
ˆ
P
P
(
)
(
)
PQ = k
open
mod
24MV, k PQ 24MV, k SQ
1.00
k PQ, k SQ
0
0
4MV, k PQ
0.95
Where is the modulation. ˆ ( ) ( ) SQ 0 0 ˆ mod S S k open =
0.90
4MV, k SQ
0
0
5
10
15
20
25
30
Depth in water [cm]
40
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