Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Flowchart of the study design. NPC, nasopharyngeal carcinoma; EBV DNA, pretreatment plasma Epstein-Barr viral deoxyribonucleic acid; IMRT, intensity-modulated; OS, overall survival; PFS, progression-free survival; LRFS, loco-regional recurrence-free survival; DMFS, distant metastasis-free survival; McNemar: analysis of variance; SD, standard deviation
