Fig. 4
Kaplan–Meier survival curves for patients with LA-NPC of LRFS (A, D, G, J), DFS (B, E, H, K), and OS (C, F, I, L) for LCV, Vpre, VRR and LCV plus VRR. LA-NPC locoregionally advanced nasopharyngeal carcinoma, Vpre tumor volume before treatment, LCV late-course volume, VRR volume regression rate, LRFS local recurrence-free survival, DFS disease-free survival, OS overall survival, HR hazard ratio; P Value indicates the difference in the c-indexes