Lower GI 2017

MERCURY experience MRI “good prognosis tumours”

If a radiologists calls all patients with <5mm spread node negative, the pre- test probability for the node negative status to be correct is 82%, the risk of local recurrence for patients with path node positive in patients mrTR3b or less, mrCRM clear and EMVI negative is 0% . For the whole MRI “good prognosis” group – risk is 3.3% Therefore overcalling nodes in patients with low risk features results in overtreatment and more harm than benefit.