Physics Bucharest 2017
6/3/2017
Cost function for biological constraints
Generalized Equivalent Uniform Dose (gEUD)
Niemierko 1997,1999 Med.Phys
a = 1 a --> -∞ a --> +∞
EUD = Dmean EUD --> Dmin EUD --> Dmax
EUD can be optimised to “equal”, (gEUD-D 0 ), “maximum” or “minimum”
gEUD : phenomenological description of the biological response to the radiation
In principle applicable to target volumes and OARs
23
Simple gEUD for 3 structures
Differential and cumulative DVH
100
Target OARs OARp
90
80
70
60
50
gEUD value
40
Min dose (55Gy,1Gy,1Gy) seen at low a
30
20
70,000
10
0
60,000
dose
10
20
30
40
50
60
50,000
40,000
Max dose (68Gy, 47Gy, 65Gy) at high a
Target OARs OARp
30,000
EUD
20,000
10,000
,000
-50
-10
1
10
50
24
a value in EUD formular
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