Neoadjuvant chemoradiotherapy (nCRT) is currently part of the standard treatment modality for locally advanced rectal cancer (LARC), enabling a certain proportion of patients to achieve pathological complete response (pCR), improving quality of life, and prolonging disease-free survival. To avoid excessive surgical trauma and postoperative complications, a non-invasive preoperative examination method independent of pathological specimens is urgently needed to accurately assess tumor restaging and efficacy, providing a reliable basis for clinical treatment planning. Magnetic resonance imaging (MRI) is currently the preferred imaging modality recommended by domestic and international guidelines for restaging and efficacy assessment after nCRT for rectal cancer, but it still has limitations. Recent literature shows that functional MRI and MRI-derived radiomics have demonstrated great potential in restaging and efficacy assessment after nCRT for rectal cancer. Therefore, this article reviews the research progress on the deficiencies and controversies of MRI in restaging and efficacy assessment after nCRT for LARC patients, aiming to provide references for clinical practice.

Neoadjuvant chemoradiotherapy (nCRT) is currently part of the standard treatment modality for locally advanced rectal cancer (LARC), enabling a certain proportion of patients to achieve pathological complete response (pCR), improving quality of life, and prolonging disease-free survival. To avoid excessive surgical trauma and postoperative complications, a non-invasive preoperative examination method independent of pathological specimens is urgently needed to accurately assess tumor restaging and efficacy, providing a reliable basis for clinical treatment planning. Magnetic resonance imaging (MRI) is currently the preferred imaging modality recommended by domestic and international guidelines for restaging and efficacy assessment after nCRT for rectal cancer, but it still has limitations. Recent literature shows that functional MRI and MRI-derived radiomics have demonstrated great potential in restaging and efficacy assessment after nCRT for rectal cancer. Therefore, this article reviews the research progress on the deficiencies and controversies of MRI in restaging and efficacy assessment after nCRT for LARC patients, aiming to provide references for clinical practice.