The N Staging System in Nasopharyngeal Carcinoma with Radiation Therapy Oncology Group Guidelines for Lymph Node Levels Based on Magnetic Resonance Imaging

To evaluate the prognostic value of variables including nodal size, level, laterality, extranodal neoplastic spread (ENS), and necrosis in patients with nasopharyngeal carcinoma (NPC) and further explore the feasibility of an N-staging system using Radiation Therapy Oncology Group (RTOG) guidelines for lymph node levels based on magnetic resonance imaging (MRI).The MRI scans of 924 patients with histologically diagnosed nondisseminated NPC were...