Lower GI 2017

IGRT for rectal cancer

- Mesorectum reported to change in shape (mainly correlated with bladder motion) - Main changes in ANT direction - Larger impact for short-course, prone position and female pts - Residual margins difficult to assess (local deformations, CTV contouring uncertainty) - «Optimal» margins often not clinically feasible (Dmin>95%/90% pts too strict criterion? Contouring uncertainty too high..?) - Issues concerning the real clinical impact in neo-adjuv RT(CHT)

Wout With daily correction

Njikamp 2012