1025 / 1542
Established need for image guidance
CTV+0.5 CTV+1.0 CTV+1.5 CTV+2.0 CTV+2.5
Skin
0
19
56
93
96
Bone
0
41
63
89
96
Soft tissue 52
89
96
100
100
Foroudi et al. Bladder cancer radiotherapy margins: a comparison of daily
alignment using skin, bone or soft tissue 2012 Clin Oncol 24 673-681
Retrospective analysis of 27 patients having daily CBCT
To determine CTV to PTV margin required to achieve coverage of bladder
when using skin, bone or soft tissue matching
% of patients where expanded CTV covered 95% of wall displacements