Accuracy of Magnetic Resonance Imaging in Staging Rectal Cancer with Multidisciplinary Team: A Single-Center Experience.

Purpose: To investigate the accuracy of magnetic resonance imaging (MRI) in preoperative staging diagnosis for rectal cancer with multidisciplinary team (MDT) discussion. Methods: The retrospective study included 377 patients of rectal cancer with preoperative MRI staging from February 2015 to April 2018, in which 137 patients (36 received MDT discussion) received neoadjuvant therapy, 240 did not (97 received MDT discussion) and direct surgery was given. With postoperative pathological stage as the standard, the accuracy of MRI in preoperative staging for rectal cancer with MDT discussion was compared with non-MDT. Results: For direct surgery group, 21 out 97 (21.6%) patients changed their therapy strategy due to the change of the stage assessment after MDT. The accuracy of MRI for the diagnosis of preoperative N stage with MDT was significantly higher than those without MDT (56.2% vs. 42.1%, P=0.021). And for those without lymph node metastasis, the accuracy of MRI was higher after MDT (61.2% vs. 37.8%, P=0.009). For neoadjuvant therapy group, 7 out of 36 (19.4%) patients altered their therapy after MDT because of the changed stage. MDT improved the accuracy of restaging N stage with MRI (70.0% vs. 33.3%, P=0.003). The accuracy of MRI in staging T stage seemed not improved after MDT in both groups. Conclusions: In conclusion, MDT discussion increased the accuracy of MRI in preoperative staging diagnosis for rectal cancer. This mode could give a more accurate clinical stage of patients, which was in favor of choosing a preferable therapy strategy.