Physics Bucharest 2017

Established need for image guidance

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

CTV+0.5 CTV+1.0 CTV+1.5 CTV+2.0 CTV+2.5

Skin Bone

0 0

19 41 89

56 63 96

93 89

96 96

Soft tissue 52

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