We investigated the effect of retropharyngeal nodal volumes (RNV) on distant metastasis in patients with advanced nasopharyngeal carcinoma (NPC). From February 2000 to June 2006, a total of 181 patients with biopsy-proven NPC, no distant metastasis, and available pre-treatment magnetic resonance imaging (MRI) were retrospectively reviewed. Most of the patients (95.6%) had stage III/IV diseases. The contour of retropharyngeal nodes ≥5mm was delineated on the axial slides of pre-treatment T2-weighted MRI without contrast enhancement. The RNV was calculated by the Eclipse™ treatment planning software. The primary end-points were subsequent distant failure rates and distant metastasis failure-free survival (DMFFS). The pre-treatment RNV in patients who developed distant failure was higher than in those without distant failure (P=0.0536). The distant failure rates between the patients with RNV > and ≤4.68cm(3) were 33.3% and 16.0%, respectively (P=0.0112). The rates of 7-year DMFFS in patients with RNV > and ≤4.68cm(3) were 66.4% and 83.5%, respectively (P=0.0043). Multivariate Cox analysis showed N-stage (P<0.001), gender (P=0.026), and RNV (P=0.088) were important predictors for DMFFS. We conclude that the RNV measured by MRI is a potential predictor of distant metastasis in patients with advanced NPC.
Copyright © 2011 Elsevier Ltd. All rights reserved.