Significance of Magnetic Resonance Imaging–Assessed Tumor Response for Locally Advanced Rectal Cancer Treated With Preoperative Long-Course Chemoradiation

Abstract

MRI-assessed complete tumor response was strongly correlated with pCR and, therefore, can be used as a surrogate marker to predict absence of viable tumor cells. Our results can be used to implement use of mrTRGs in larger prospective correlative studies as a tool to select patients for whom deferred surgery may be appropriate. Also, those with a poor response may be offered further treatment options before definitive surgery.