title: [Long-term efficacy of prophylactic upper neck irradiation for stage N0 nasopharyngeal carcinoma].
abstract: OBJECTIVE
  Whether prophylactic irradiation should cover the whole neck or just the upper neck for nasopharyngeal carcinoma (NPC) patients, without neck lymph node metastasis (N0), remains controversial. This study was to assess the rationality of prophylactic upper neck irradiation for stage N0 NPC patients.
  
  
  METHODS
  Clinical data of 432 stage N0 NPC patients were analyzed. All patients were treated with radical radiotherapy alone. The extent of prophylactic irradiation was limited to the upper neck of the patients. Median radiation doses were 70 Gy for the primary tumors, and 50 Gy for the upper necks. Kaplan-Meier method was used to analyze survival rates and neck recurrence rates. Log-rank test was used to compare neck recurrence rates in patients with or without nasopharyngeal recurrence. Cox proportional hazards model was used to evaluate the prognostic factors for neck control.
  
  
  RESULTS
  Seventeen out of 432 patients had neck recurrence. The 5-year control rate of the neck was 96.06%. Among the 17 patients with neck recurrence, 6 had concurrent nasopharyngeal relapse. The occurrence rates of neck recurrence alone were 0.93%(4/432) in the upper necks and 1.62% (7/432) in the lower necks (P=0.937). The neck recurrence rates were 9.52% (6/63) and 2.98% (11/369) in patients with and without nasopharyngeal recurrence, respectively (P=0.002). Nasopharyngeal recurrence was the only independent prognostic factor for neck control.
  
  
  CONCLUSIONS
  The overall neck recurrence rate is low for stage N0 NPC patients after receiving irradiation. Prophylactic upper neck irradiation is reasonable for stage N0 NPC patients.
authors.affiliation: Department of Radiation Oncology, Affiliated Tumor Hospital, Medical School, Shantou University, Shantou, Guangdong, 515031, P. R. China.
authors.forename: Chuang-Zhen
authors.initials: CZ
authors.lastname: Chen
authors.forename: De-Rui
authors.initials: DR
authors.lastname: Li
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Chen
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Li
authors.forename: Long-Jia
authors.initials: LJ
authors.lastname: Guo
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009333:Neck / Q000528:radiation effects*; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D012189:Retrospective Studies