Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy oleh Yu-Xiang He, Ying Wang, Peng-Fei Cao, Lin Shen, Ya-Jie Zhao, Zi-Jian Zhang, Deng-Ming Chen, Tu-Bao Yang, Xin-Qiong Huang, Zhou Qin, You-Yi Dai, Liang-Fang Shen