Lower GI 2016

The Royal Marsden

Assessing response

Method

Prospectively validated against DFS outcomes

MRI DWI

No – many retrospective quantitative cut-offs and qualitative assessments – none prospectively validated

DCE-MRI

No – many retrospective values proposed – none validated No – but retrospective SUV cut-offs proposed – unverified prospectively

PET-CT

mrVolume assessment

Yes: >80% volume reduction

mrTRG

Yes : TRG1-5 validated prospectively and against outcomes

mrT and mrN stage

validated prospectively and against outcomes