[Evaluation of current imaging in restaging rectal cancer after neoadjuvant therapy]

The combination of preoperative chemoradi-otherapy and surgery has become the standard treatment for locally advanced rectal cancer. Up to 30% of patients received pathologic complete response(pCR) after neoadjuvant therapy, for whom low rates of local recurrence and improved outcome after surgery were achieved. Given that, some authors have recommended local resection for clinical extensive response or non operative "wait and see" policy for clinical complete response(cCR) respectively, in which radical surgery-associated complication and dysfunction can be avoided. Current imaging can provide excellent accuracy in primary staging of rectal cancer, however, when used for restaging, the ability is less satisfactory, especially for pCR prediction, as a result of modification on tumor and surrounding tissue induced by neoadjuvant therapy. The question on how to identify patients with pCR before surgery has received more attention recently. On the basis of pathological findings after surgery, in this article, we review the reliability and predictive ability of current imaging for restaging and pCR after preoperative chemoradiotherapy in rectal cancer.