title: [Risk factors of level Ib lymphadenopathy in nasopharyngeal carcinoma].
abstract: OBJECTIVE
  To analyze the risk factors for level Ib lymph node enlargement on CT in patients with nasopharyngeal carcinoma (NPC) and provide clinical evidence for defining the indications of prophylactic level Ib irradiation.
  
  
  METHODS
  A total of 435 newly diagnosed NPC patients receiving radiotherapy in Nanfang Hospital in the past 2 years were enrolled in this analysis. The correlations were analyzed with Logistic regression between level Ib lymphadenopathy and the clinical risk factors including T stage, N stage, diameter of level II lymph nodes, submandibular gland involvement, nasal cavity involvement, oropharyngeal involvement, and involvement of 4 or more lymphatic drainage regions.
  
  
  RESULTS
  Univariate analysis showed that level Ib lymphadenopathy were positively correlated with N stage (P=0.023), submandibular gland involvement (P=0.045), and level II lymph node diameter (P<0.001). Multivariate Logistic regression analysis suggested a significant correlation only between the diameter of the level II lymph nodes and level Ib lymphadenopathy (P=0.013).
  
  
  CONCLUSIONS
  Level Ib lymphadenopathy is positively correlated with the size of ipsilateral level II lymph nodes in NPC patients.
authors: Department of Radiotherapy, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. E-mail: rukawa1989@yeah.net.
authors: Gongjun
authors: G
authors: Yuan
authors: Xiaokang
authors: X
authors: Zheng
authors: Xiaoxia
authors: X
authors: Zhu
authors: Zhe
authors: Z
authors: Wang
authors: Wen
authors: W
authors: Song
authors: Hong
authors: H
authors: Zhang
authors: Zhou
authors: Z
authors: Sha
mesh_terms: D002277:Carcinoma; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008206:Lymphatic Diseases / Q000453:epidemiology*; D008207:Lymphatic Metastasis; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D009333:Neck; D010256:Paranasal Sinuses; D012307:Risk Factors; D013363:Submandibular Gland