ATP 2016

Image guidance • Patients position less well than we think • IGRT allows more accurate delivery of dose  Deliver the dose to where you planned  ? Reduce PTV margins (don’t over-reduce)  If no reduction of margin, delivers dose more precisely to target and (probably) normal tissue  Especially important with steep dose gradients

10 11 12 13 14 15

 Prostate

 Skin set up  Pelvic bone EPID  Seed IGRT

0 1 2 3 4 5 6 7 8 9

3D Displacement (mm)

 (Dr Yvonne Rimmer)

Skin set-up

Bone

Seeds