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Physical dose
Target coverage (min, max, …)
Target homogeneity
OAR exposure (max, …)
Surrounding tissues
…
Biological effect
TCP, NTCP
EUD
…
21
ESTRO physics course 2017
DVH goals
The inverse problem
How do we create the cost function
Optimise:
Cost function
22
2
0
0
2
2
1
1
1
2
0
H
1
1
1
OAR i
i
i
OAR
OAR
OAR i
i
OAR
OAR
Ti
i
T
T
d d d d
n
d
n
d d
n
C
Penalty for not having
uniform dose d
0
(optimising uniformity in target)
Penalty for any
dose to OAR
(minimising the mean of
the OAR)
Penalty for dose above
“tolerance dose d
0
“ in OAR
(keeping max dose below d
0
)
Is the
relative weight
factor
H(x)