title: Update report of nasopharyngeal carcinoma treated with reduced-volume intensity-modulated radiation therapy and hypothesis of the optimal margin.
abstract: OBJECTIVE
  To establish the minimally required margins in different directions measured from GTV in the definitive treatment of nasopharyngeal carcinoma (NPC) using IMRT based on the 5-year results.
  
  
  METHODS
  Between November 2003 and May 2007, 414 patients with non-metastatic NPC were treated with IMRT according to our institutional protocol. Treatment outcomes at 5 years were analyzed. Distances from GTV-T to CTV2 (i.e., CTV 59.4 Gy) in 6 directions (anterior, posterior, superior, inferior, and bilateral) were measured and analyzed.
  
  
  RESULTS
  The 5-year estimated overall survival (OS), disease free survival (DFS), local control (LC) were 80%, 77% and 95%, respectively. For the margins measured from GTV-T to CTV2, margins used with T4 disease were significantly and uniformly smaller than the whole group in all the 6 directions (P=0.000, 0.000, 0.000, 0.000 and 0.046, respectively). However, no increase of local recurrence was associated to this limited margins used.
  
  
  CONCLUSIONS
  Our 5-years' experience showed a very high LC rate. The strategy we used for CTV delineation was safe and reliable. Determined CTV through GTV expansion to a minimally required margin, using GTV+margin (used in our T4 patients)+the whole nasopharyngeal mucosa, especially for the patients with early T disease, might be feasible.
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian, China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian, China. Electronic address: panjianji@126.com.
authors.forename: Jianji
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian, China.
authors.forename: Qiaojuan
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China.
authors.forename: Cairong
authors.initials: C
authors.lastname: Hu
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian, China.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Zong
authors.affiliation: Department of Radiation Oncology, Cancer Hospital of Fujian Medical University, Fuzhou, Fujian, China.
authors.forename: Xiuchun
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Shanghai Proton and Heavy Ion Center, Shanghai, China; Department of Radiation Oncology, Fudan University, Shanghai Cancer Center, Shanghai, China. Electronic address: mdcljj@nus.edu.sg.
authors.forename: Jiade Jay
authors.initials: JJ
authors.lastname: Lu
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D016896:Treatment Outcome
keywords: Chemoradiation; IMRT; Intensity-modulated radiation therapy; Nasopharyngeal carcinoma; Optimal margins; Radiotherapy