To delineate the prognostic value of primary gross tumor volume (GTVp) for patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated with concurrent chemoradiotherapy.Study Design
Analysis of prognostic variables in a prospective cohort.Setting
Department of Radiotherapy, First Affiliated Hospital of Guangxi Medical University, China.Subjects and Methods
Between January 2006 and August 2008, 249 patients with stage III-IVb NPC, all treated by intensity-modulated radiotherapy plus concurrent chemotherapy, were included in this multicenter prospective study. GTVp was measured with treatment-planning computed tomography or magnetic resonance imaging scans.Results
GTVp was significantly associated with locoregional control, distant metastasis, and overall survival for patients with advanced NPC. Furthermore, T classification was not an independent prognostic factor. In receiver operator receiver operating characteristic curve analysis, 33 mL was determined as the cutoff points of GTVp for OS and locoregional control. Patients with a GTVp ≥33 mL had poorer OS, worse locoregional control, and more distant metastasis than patients with a GTVp <33 mL (P = .006, .009, .002, and .007, respectively).Conclusions
GTVp had significant prognostic value for patients with advanced NPC. The incorporation of GTVp could improve the current TNM classification system.