CT扫描对鼻咽癌N分期的作用

Effect of computed tomography on N staging for nasopharyngeal carcinoma

目的：目前鼻咽癌各分期的T标准均包含CT内容，本研究旨在探讨CT扫描在鼻咽癌N分期的作用。方法：194例病理确诊的初诊鼻咽癌病人，均行颅底、鼻咽及颈部CT增强扫描，分析临床检查及CT影像资料。结果：72例N0病人有15例(20.8％)升级为N1；59例N1病人中有2例（3.4％）升级为N2，86例临床单侧淋巴结转移病人有13例（15.1％）CT影像发现双侧淋巴结转移。CT扫描颈部淋巴结的大小为：最大横径为(16.7±10.1)mm；最大纵径为(18.9±14.1)mm。临床触诊最大横径为(27.4±17.4)mm；最大纵径为(28.6±18.7)mm。临床触诊淋巴结大小与CT影像上淋巴结大小差别显著(P<0.001)。咽后淋巴结转移率为32.9％(64/194)。N0病人咽后淋巴结转移率为20.3％。结论：结合颈部增强CT扫描，部分病人N分期升级，同时明确淋巴结的数目和大小，使预后及放射治疗计划发生改变，建议鼻咽癌的N分期标准应包含CT内容。

Objective： Currently the T classification of tumor staging systems has been developed incorporating the knowledge gleaned from CT scan. The aim of this study is to clarify whether CT scan is useful in the clinical staging of nasopharyngeal carcinoma (NPC). Methods： The contrast enhanced CT scan of skull base, nasopharynx, parapharyngeal space and neck for 194 consecutive patients with newly diagnosed NPC was performed prior to all treatment using the elscint CT twin. Results： there were 15 (20.8％ ) patients up staged from N0 to N1, 2 (3.4％ ) patients up staged from N1 to N2, Of 86 patients clinically with unilateral cervical metastases, 13 (15.1％ ) patients showed bilateral cervical metastases on CT imaging. The size of cervical lymph nodes as determined by CT scan was as follows： maximal axial diameter： (16.7± 10.1) mm; longitudinal diameter： (18.9± 14.1) mm. The size of lymph nodes measured clinically： maximal axial diameter ： (27.4± 17.4)mm; longitudinal diameter： (28.6± 18.7)mm. The tumor size as determined by two methods was significant different (P< 0.001). The incidence of retropharyngeal lymphadenopathy was 32.9％ (46/194). In 59 patients with N0 disease,retropharyngeal lymphadenopathy was found in 12 (20.3％ ) patients. Conclusion： Using CT imaging, the N staging of a significant proportion of NPC patients will be up staged, so that the prognosis and treatment plan could be changed. CT imaging can identify the size and number of cervical lymph nodes clearly, and should be considerd for routine staging of NPC.