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Delineation effect on dose
Observer 1 Observer 2 Mean
IMRT
135 cm3
115 cm3
125 cm3
3D Conformal 241 cm3
195 cm3
218 cm3
Mean
188 cm3
155 cm3
Observer and technique effect on the irradiated volume
Mean Planning Target Volume: 36.3 cm3
Mean observer effect:
33 cm3
Mean technique effect:
93 cm3
•Rasch et al IJROBP 2002
Delineation effect on dose
0
10
20
30
40
50
60
0
0.5
1
1.5
2
2.5
3
3.5
4
minimum distance between the boost PTV and the chiasm (cm)
vol% receiving < 95% of the
prescribed dose
IMRT plans (
■
)
3D Conformal plans (
▲
)
Dose to the target and distance from the OAR
•Rasch et al IJROBP 2002
Observer variation in the neck
18 observers
– MCA, AvL, VUMC, ARTI, RISO, MST, MCH,
UMCG, RIF, MAASTRO, UMCN, DDHK,
UMCU, Leuven, Middelheim,
1 patient
Delineation according to guidelines as
published by Gregoire et al
– R&O 2003
Prevertebral Level 1-2
Gregoire et al 2003 R&O
2 top
2 mid