1079 / 1224
80%
82%
84%
86%
88%
90%
92%
94%
96%
98%
100%
65
75
85
95
105
115
local control
total treatment D
90
CTV
HR
(EQD2
a/b
=10Gy
)
SD 5%
SD 10%
SD 15%
SD 20%
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
55
60
65
70
75
80
85
morbidity
total treatment D
2cm³
(EQD2
a/b
=3Gy
)
SD 10%
SD 20%
SD 30%
model
Example: random uncertainties for target + OAR
effect of random intra-/interfraction variation on D
90
, D
2cm³
and dose-response
Example: 75Gy,
random variation of rectum D
2cm³
:
•
D
D
2cm³
=
±
10%/fx -> observed NTCP 7.5 %
(vs 7.3% model prediction)
•
D
D
2cm³
=
±
20%/fx -> observed NTCP 8.9 %
•
D
D
2cm³
=
±
30%/fx -> observed NTCP 10.5 %
•
Model predicts 10.5% morbidity NTCP @ 80Gy EQD2!
OAR
target
For target – differences in TCP < 0.5%
TCP
NTCP