1095 / 1544
Prostate
P.M.A. van Haaren et al. / Radiotherapy and Oncology 90 (2009) 291–298
293
and bladder are created. The latter effectively reduc
around BV to zero towards rectum and bladder. IMR
made using PLATO/ITP (Nucletron, Veenendaal, The
and were created such that the 66.5 Gy-isodose su
70 Gy) enclosed the PTV and the 72.2 Gy-isodose su
76 Gy) enclosed the EBV as much as possible
[17,
straints for the organs-at-risk (OARs) during the opti
bladder
CTV
BV
EBV
PTV
PZ
rectum
cog
Fig. 1.
Schematic sagittal view of volumes taken into account du
zation. CTV, clinical target volume (= prostate + vesicles); BV
(= prostate); PTV, planning target volume (= CTV + 8 mm; dashed
boost volume (= BV + 8 mm, excluding overlap with rectum and
PZ, peripheral zone; cog, center of gravity of prostate.
P.M.A. van Haar
Fig. 2.
Average dose (
D
mean
) and
D
99%
to CTV, boost volume and peripheral zone for the static, uncorrected and corrected plans, with respect to the prescription dose (PD) and
95% of PD. Box plots show medians, and 25th and 75th percentiles; whiskers are 10th and 90th percentiles; dots represent outliers.
Table 2
Dose parameters for targets and organs-at-risk (OARs) of all static, uncorrected and corrected plans, and changes with respect to the static plans. Data are mean ± SD (range).
*
p
< 0.05 vs. BV and vs. PZ;
!
p
< 0.05 vs. CTV and vs. BV.
Parameter
Static
Uncorrected
Corrected
Uncorrected-static
Corrected-static
Targets
CTV
D
mean
(Gy)
74.2 ± 1.2
73.8 ± 1.4
74.0 ± 1.2
"
0.4 ± 0.9
"
0.2 ± 0.4
D
99%
(Gy)
69.7 ± 1.4
66.6 ± 5.0
68.8 ± 2.6
"
3.1 ± 4.6
*
(
"
25.7
"
+ 1.5)
"
1.0 ± 2.2
*
(
"
16.5
"
+ 1.3)
BV
D
mean
(Gy)
75.0 ± 1.2
74.6 ± 1.3
74.8 ± 1.2
"
0.3 ± 0.7
"
0.1 ± 0.3
D
99%
(Gy)
70.9 ± 1.6
68.7 ± 4.0
70.5 ± 1.8
"
2.3 ± 3.6 (
"
21.3
"
+ 2.2)
"
0.5 ± 0.9 (
"
5.8
"
+ 0.9)
PZ
D
mean
(Gy)
73.3 ± 1.7
72.2 ± 2.7
73.1 ± 1.7
"
1.2 ± 2.3
!
"
0.2 ± 0.5
D
99%
(Gy)
71.2 ± 1.9
69.3 ± 4.3
70.9 ± 2.0
"
1.9 ± 3.8 (
"
20.5
"
+ 5.3)
"
0.3 ± 0.8 (
"
3.8
"
+ 2.2)
OAR
294
Estimated delivered dose of prostate IMRT treatments
Ch nges can be accounted for by cor ection
(IGRT) protocols or sufficient margins, when
movement is limited <10mm
215 patients