Restaging rectal cancer following neoadjuvant chemoradiotherapy

Table 2 Take-home message

Re-staging
Why	It allows for the development of a tailored surgical treatment with the goal of avoiding poor oncological outcomes and overtreatment
When	It remains unclear. Experts recommend: (1) For patients receiving neoadjuvant chemoradiotherapy or short-course radiotherapy, the 2-step approach, at 12 wk and 16-20 wk after starting treatment if organ preservation is a priority; (2) For patients receiving total neoadjuvant therapy, assessment at 20-38 wk after commencing treatment according to the duration of the treatment; and (3) In case of ncCR, a second assessment 3 mo later taking into account initial tumour stage and treatment approach, if organ preservation is a priority. There is insufficient evidence to recommend proper timing for the earlier identification of patients with a poor response before the conventional time. Nevertheless, experts advise caution and selective earlier imaging in patients with tumours featuring certain high-risk characteristics (such as advanced cT stage)
How	Digital rectal examination, endoscopy and pelvic MRI for local tumour restaging; Chest and abdominal CT for distant disease. The current aim of local response assessment is not correct T-staging but the accurate differentiation between “good responders” (who are ypT0N0 or ypT1N0) and “poor responders.” In the latter, the risk of incomplete resection, such as MRF positivity, adjacent organ or anal sphincter infiltration, and residual lateral pelvic node involvement should also be identified

CT: Computed tomography; ncCR: Near clinical complete response; MRI: Magnetic resonance imaging.