333例鼻咽癌咽后淋巴结转移特点的MRI分析

目的了解鼻咽癌咽后淋巴结的发生率及特征，探讨其与受累部位、颈部淋巴结转移的关系。方法回顾性分析333例经病理证实、无远处转移的初诊鼻咽癌患者MRI资料。根据2008临床分期标准进行分期。采用率的比较分析咽后淋巴结转移与临床分期、肿瘤侵犯部位及颈部淋巴结转移的关系。结果（1）咽后淋巴结阳性率为66.3%，其中单侧41.4%，双侧24.9%；不同T、N分期（T1、T2、T3、T4；N1b、N2、N3）的咽后淋巴结转移率均不同，其中T1期均低于T2、T3以及T4期（P＜0.05），N1b期均较N2、N3期低（P＜0.05）；（2）茎突前间隙、颈动脉鞘区、口咽、椎前肌、翼内肌等结构侵犯者的咽后淋巴结转移发生率均明显高于其未侵犯者（P＜0.05）；（3）全组病例颈淋巴结转移率为82.0%,其中咽后淋巴结阳性者高于阴性者（87.8% vs.70.5%，P＜0.05）；双侧咽后淋巴结转移者高于单侧转移者（94.0% vs. 84.1%，P＜0.05）；（4）咽后淋巴结最大直径≤20 mm与最大直径＞20 mm患者的颈淋巴结各区转移率差异无统计学意义（P＞0.05）。结论（1）鼻咽癌咽后淋巴结转移率高与茎突前间隙、颈动脉鞘区、椎前肌、翼内肌及口咽侵犯相关；（2）鼻咽癌咽后淋巴结转移影响颈淋巴结的转移；（3）咽后淋巴结的直径大小与颈淋巴结各区转移无相关性。

MRIAnalysis ofMetastasis ofRetropharyngealLymphNodes in 333PatientswithNasopharyngealCarcinoma

Objective
To investigate the incidence and characteristic of retropharyngeal lymph nodes and explore its relationship with
located invasion and metastasis of cervical lymph nodes in nasopharygeal carcinoma.
Methods
Retrospectively reviewed the data of MRI from 333 NPC patients with non-distant metastasis and newly diagnosed with NPC by pathology. And the 2008 staging system was used to determine the clinical stage of each NPC patients. And the rate comparison was used
to explore the relationship between the RLN and the invaded lication and the metastasis of cervical lymph nodes.
Results
(1) The positive rate of retropharyngeal lymph node was 66.3%(unilateral was 41.4% and bilateral was 24.9%). The retropharyngeal lymph node metastasis rate of T stages was different from N stages. And the positive rate of T1 stage was significantly lower than that of T2, T3 and T4 stage（P<0.05）. N1b had a significantly lower positive rate compared with N2, N3 stage. (2) The positive rate of retropharyngeal lymph node of patients with invasions of pre-styloid space, carotid sheath, oropharynx, prevertebral muscle and medial pterygoid were significantly higher than that of patients without invasions. (3) The positive rate of cervical lymph node was 82.0%(273/333),
thereinto, patients with retropharyngeal lymph node metastasis had significantly higher positive rate than those without metastasis
(87.8%vs. 70.5%，P<0.05). The unilateral metastasis was lower than the bilateral (84.1% vs. 94%)(P<0.05). (4) The positive rate of cervical lymph node was not significantly different between patients with the more than 20 mm diameter of retropharyngeal lymph node and those with less than 20 mm（P＞0.05）.
Conclusion
(1) The high positive rate of retropharyngeal lymph node is related to the invasion of pre-styloid space, carotid sheath, oropharynx, prevertebral muscle and medial pterygoid. (2) The metastasis of retropharyngeal lymph node influences the invasion of cervical lymph node.(3) The
diameter of retropharyngeal lymph node has no correlation with the located of invation of cervical lymph node.