title: Effect of intensity-modulated radiotherapy versus two-dimensional conventional radiotherapy alone in nasopharyngeal carcinoma.
abstract: BACKGROUND
  Albeit intensity-modulated radiotherapy (IMRT) is currently the recommended radiation technique in treating nasopharyngeal carcinoma, the effect of IMRT versus two-dimensional conventional radiotherapy (2DCRT) alone is still contradictory.
  
  
  RESULTS
  In the original unmatched cohort of 1198 patients, IMRT obtained comparable 5-year overall survival (OS) (91.3% vs 87.1%, P = 0.120), locoregional relapse-free survival (LRFS) (92.3% vs 90.4%, P = 0.221) and distant metastasis-free survival (DMFS) (92.9% vs 92.1%, P = 0.901) to 2DCRT. In the propensity-matched cohort of 604 patients, no significant survival differences were observed between the two arms (5-year OS 90.9% vs 90.5%, P = 0.655; LRFS 92.5% vs 92.4%, P = 0.866; DMFS 92.5% vs 92.9%, P = 0.384). In multivariate analysis, IMRT did not significantly lower the risk of death, locoregional relapse or distant metastasis, irrespective of tumor stage.
  
  
  METHODS
  Overall, 1198 patients who underwent IMRT (316 patients) or 2DCRT (882 patients) without any chemotherapy was retrospectively analyzed. Patients in both arms were matched at equal ratio using propensity-score matching method. OS, LRFS and DMFS were assessed with Kaplan-Meier method, log-rank test and Cox regression.
  
  
  CONCLUSIONS
  In this propensity-matched study, IMRT showed no survival advantage over 2DCRT alone in nasopharyngeal carcinoma.
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Pu-Yun
authors.initials: PY
authors.lastname: OuYang
authors.affiliation: Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Dingbo
authors.initials: D
authors.lastname: Shi
authors.affiliation: Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Zhu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Lu-Ning
authors.initials: LN
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Ze-Ying
authors.initials: ZY
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Lan
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Yuan-Hong
authors.initials: YH
authors.lastname: Gao
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Wuguo
authors.initials: W
authors.lastname: Deng
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
authors.forename: Fang-Yun
authors.initials: FY
authors.lastname: Xie
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary; D016009:Chi-Square Distribution; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms; D009364:Neoplasm Recurrence, Local; D010610:Pharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D057216:Propensity Score; D016016:Proportional Hazards Models; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: intensity-modulated radiotherapy; nasopharyngeal carcinoma; propensity score matching; two-dimensional conventional radiotherapy