1080 / 1224
0%
5%
10%
15%
20%
55
60
65
70
75
80
85
morbidity
total treatment D2cm³ rectum (EQD2
a/b
=3Gy
)
1Fx
2Fx
3Fx
4Fx
5Fx
model
0,9
0,91
0,92
0,93
0,94
0,95
0,96
0,97
0,98
0,99
1
75
85
95
105
115
probability
total treatment dose (EQD2
a/b
=10Gy
)
1Fx
2Fx
3Fx
4Fx
5Fx
model
Example: influence of the number of BT Fx
Random uncertainties and dose response for different fractionation schemes
Example: random uncertainty
D
D
2cm³
=
±
20%/fx
:
•
nFx=5 => observed morbidity @75Gy 8.5%
•
nFx=4 => observed morbidity @75Gy 8.9%
•
nFx=3 => observed morbidity @75Gy 9.4%
•
nFx=2 => observed morbidity @75Gy 10.3%
•
nFx=1 => observed morbidity @75Gy 12.3%
OAR
target
For target: using 1 fx vs 2-5 fx results in
~0.5% lower response probability than
predicted by model
TCP
N TCP