[Application of imaging diagnosis in watch and wait strategy for locally advanced rectal cancer patients after...

After neoadjuvant chemoradiotherapy(nCRT), 15%-40% of rectal cnacers has a pathological complete response (pCR), with non-malignant cells demonstrated in histological assessment of the surgical resection specimen. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who achieve a clinical complete response (cCR), that is "Watch and Wait strategy" (W&W). One of the major challenges in the W&W of rectal cancer is the careful and precise selection of patients suitable for this approach. The published series on W&W has all used different modalities to assess response post nCRT, including the MSKCC's three-tiered evaluation plan and Mercury's mrTRG criteria. Except significant heterogeneous results, the evidence available comes mostly from retrospective cohort studies, furthermore, there is a lack of data of long-term outcomes. How to accurately screen pCR patients preoperatively is an important and difficult issue of clinical concern.