MRI-Identified Multidimensional Nodal Features: Predict Survival and Concurrent Chemotherapy Benefit for Stage II Nasopharyngeal Carcinoma

Abstract

<h3>Purpose/Objective(s)</h3> Reliable predictors are urgently needed to identify stage II nasopharyngeal carcinoma (NPC) patients who could benefit from concurrent chemoradiotherapy (CCRT). We determined the value of comprehensive nodal features for predicting survival and CCRT benefit for stage II NPC patients. <h3>Materials/Methods</h3> In all, 242 patients diagnosed with stage II NPC from 2007 to 2017 receiving CCRT (N=84) or intensity-modulated radiotherapy alone (IMRT, N=158) were enrolled. Relationships between diverse nodal features and survival outcomes were investigated. Significant predictors of overall survival (OS) in multivariable analysis were scored according to hazard ratio values. Based on total scores of each patient, a risk calculator–nodal feature-based prognostic model was derived to predict OS and CCRT benefit. The Kaplan–Meier method was applied to estimate survival outcomes. C-indexes were used to compare predictive efficiency between the risk model and TNM stage. <h3>Results</h3> Age ≥50 years (HR=2.93; P=0.01), ≥4 nodes (HR=2.80; P=0.03) and level III node involvement (HR=3.81; P=0.01) were independent prognostic factors for worse OS. The C-indexes of the risk model and TNM stage for predicting OS were 0.76 and 0.53, respectively. Intermediate-risk patients receiving CCRT had better 5-year OS than those receiving IMRT (89.5%, 77.8%; P=0.02). No benefit was found for low-/high-risk patients. <h3>Conclusion</h3> The number of metastatic nodes and level III node involvement are critical for predicting OS and CCRT benefit for stage II NPC patients. The prognostic model based on these variables could be used to optimize treatment intensity, suggesting that CCRT may be the optimal strategy for intermediate-risk populations; high-risk patients may require more intensive treatment, while IMRT alone is adequate for low-risk patients.