Lower GI 2017

Early Tumours

GTV_A = Primary Tumour CTV_A = GTV_A + 5mm

GTV_N = Involved Nodes CTV_N = GTV_N + 5mm

CTV_ALL = CTV_A + CTV_N + CTV_E

PTV_Anal

PTV_Nodes

PTV_ELEC

= GTV_A + 10mm*

= GTV_N + 5mm*

= CTV_ALL + 5 mm

* These margins are appropriate for patients treated with daily online imaging. We recommend centres audit their local set up regularly.