A magnetic resonance imaging-based lymph node regression grading scheme for nasopharyngeal carcinoma after radiotherapy

Motivation: After curative radiotherapy (RT), there is no commonly accepted method to distinguish between patients with residual disease that may eventually cause disease progression and those who are already cured of the disease in nasopharyngeal carcinoma (NPC). Goal(s): We proposed a four-category MRI-based lymph node regression (MRI-LRG) grading system to investigate its prognostic value for NPC after RT. Approach: 387 NPC patients were included in this retrospective study. Lymph node regression grade was assessed on MRI based on the areal analysis of RT-induced fibrosis and the residual tumor. Results: Our results showed that MRI-based LRG was an independent prognostic factor for progression-free survival. Impact: A nomogram, based on LRG-sum, pretreatment EBV DNA, post-RT EBV DNA, sex and N stage factors, was proved to be useful to facilitate risk stratification in NPC. This approach might help to stratify treatment modalities and develop a more effective tailored surveillance program in patients with NPC.