Rectal cancer: how accurate can imaging predict the T stage and the circumferential resection margin?

Background: One of the concerns after rectal cancer surgery is the local recurrence rate. Randomized trials have shown that the best local control rate for rectal cancer patients overall is obtained by a short preoperative course of radiotherapy followed by a total mesorectal excision, but there are however subgroups of rectal cancer patients with varying risks of recurrences. Discussion: At one end of the continuum are patients with stage I disease who are at very low risk of local recurrence. At the other end are the patients with locally advanced tumor who are at very high risk, and who would benefit from a more extensive neoadjuvant treatment schedule. This kind of differentiated treatment can be performed only when there is an accurate tool to identify preoperatively the different risk groups. There is recent evidence, suggesting that MRI can serve for this purpose, because it accurately predicts the tumor free circumferential resection margin at TME. Conclusion: This article provides a literature review of the value of preoperative imaging in rectal cancer surgery.