Circumferential resection margin assessment on MRI of rectal cancer

The circumferential resection margin (CRM) has been shown to be a good predictor of the outcome of the total mesorectal resection surgical procedure in colorectal cancer. The CRM is increasingly used as a key parameter in patient management for colorectal cancer. It has been proposed that CRM can be estimated from MRI volumes taken pre-operatively; but to date the estimation of CRM is slice-based, hence two dimensional. We report a fully three-dimensional method to estimate the CRM, taking account of the MRI slice orientation used during the acquisition process. Prior to this, we segment the rectum and mesorectum. Preliminary results are reported for 10 patient cases, and a further large set are currently being analysed and results will be available at the time of the conference.