Tumor Control Probability After Re-irradiation Using Intensity Modulated Radiation Therapy for Locally-Recurrent Nasopharyngeal Carcinoma

1.048-2.442, pZ 0.030; OS: RR, 1.662, 95% CI, 1.048-2.635, pZ 0.031). Chemotherapy improved both DMFS (RR, 1.813, 95% CI, 1.172-2.805, p Z 0.008) and OS (RR, 2.360, 95% CI, 1.498-3.717, p Z 0.000). Conclusions: Primary tumor volume could probably predict LRC of NPC patients and PTV 40 mL might be the cut-point. PNV also has some possible predictive significance, but more data are needed. They should be considered in the TNM staging system of NPC for better estimating prognosis. Author Disclosure: F. Mei: None. L. Jinyi: None. W. Weidong: None. F. Zhixuan: None. F. Binyu: None. L. Jie: None. Z. Shichuan: None.