title: A model to predict the risk of lethal nasopharyngeal necrosis after re-irradiation with intensity-modulated radiotherapy in nasopharyngeal carcinoma patients.
abstract: For patients with nasopharyngeal carcinoma (NPC) who undergo re-irradiation with intensity-modulated radiotherapy (IMRT), lethal nasopharyngeal necrosis (LNN) is a severe late adverse event. The purpose of this study was to identify risk factors for LNN and develop a model to predict LNN after radical re-irradiation with IMRT in patients with recurrent NPC.
  
  
  
  Patients who underwent radical re-irradiation with IMRT for locally recurrent NPC between March 2001 and December 2011 and who had no evidence of distant metastasis were included in this study. Clinical characteristics, including recurrent carcinoma conditions and dosimetric features, were evaluated as candidate risk factors for LNN. Logistic regression analysis was used to identify independent risk factors and construct the predictive scoring model.
  
  
  
  Among 228 patients enrolled in this study, 204 were at risk of developing LNN based on risk analysis. Of the 204 patients treated, 31 (15.2%) developed LNN. Logistic regression analysis showed that female sex (P = 0.008), necrosis before re-irradiation (P = 0.008), accumulated total prescription dose to the gross tumor volume (GTV) ≥145.5 Gy (P = 0.043), and recurrent tumor volume ≥25.38 cm(3) (P = 0.009) were independent risk factors for LNN. A model to predict LNN was then constructed that included these four independent risk factors.
  
  
  
  A model that includes sex, necrosis before re-irradiation, accumulated total prescription dose to GTV, and recurrent tumor volume can effectively predict the risk of developing LNN in NPC patients who undergo radical re-irradiation with IMRT.
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Ya-Hui
authors.initials: YH
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Wei-Xiong
authors.initials: WX
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Biodevices and Diagnostics, Institute of Bioengineering and Nanotechnology, Singapore, 138669, Singapore.
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Radiation Therapy, 3rd Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, Guangdong, P. R. China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, Guangdong, P. R. China.
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Hu
authors.initials: H
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Liang-Ru
authors.initials: LR
authors.lastname: Ke
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Xing
authors.initials: X
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China. xiangyq@sysucc.org.cn.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China. xiangyq@sysucc.org.cn.
authors.forename: Yan-Qun
authors.initials: YQ
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China. guoxiang1010@gmail.com.|Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, 510060, Guangdong, P. R. China. guoxiang1010@gmail.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015999:Multivariate Analysis; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009305:Nasopharynx / Q000473:pathology* / Q000528:radiation effects; D009336:Necrosis / Q000209:etiology; D011832:Radiation Injuries / Q000209:etiology / Q000473:pathology; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D000069475:Re-Irradiation / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Intensity-modulated radiotherapy; Nasopharyngeal carcinoma; Necrosis; Re-irradiation