Lower GI 2017

IGRT for rectal cancer: boost

Maggiulli 2012

- IGRT focused on the boost volume (simpler assessment of margins ?) - Rectal motion as a surrogate of GTV/CTVboost - Reported trend for rectal volume reduction and for shape variation (Njikamp 2012, Maggiulli 2012, Raso 2015) - Residual deformation error after rigid correction: anisotropic, higher in the first few fractions - Relatively small «optimal» margins reported (especially if excluding the first fractions)….mainly 5-15 mm - Larger motion in female pts

Raso 2015

….to be better discussed later (IGRT & adaptive)