鼻咽癌淋巴结转移的磁共振成像研究

Magnetic resonance imaging of lymph node metastasis in nasopharyngeal carcinoma

目的探讨鼻咽癌淋巴结转移的影像学规律。方法搜集初治鼻咽鳞癌315例,全部行常规鼻咽部MRI平扫及增强检查,采用2003年RTOG推荐的头颈部肿瘤淋巴结转移的分区标准。结果315例中254例淋巴结转移,跳跃性淋巴结转移4例。254例转移淋巴结中,81例仅左侧转移,72例仅右侧转移,101例为双侧转移；73例仅咽后淋巴结转移,21例仅有颈淋巴结转移,160例为咽后及颈淋巴结均有转移。原发肿瘤单纯累及顶后壁的89例中,78%累及咽后淋巴结；单纯累及侧壁的43例中,49%累及咽后淋巴结(x^2=11．00,P＜0．01)。原发肿瘤T1、T2、T3、T4期的淋巴结转移率分别为73．5%、91．2%、71．9%、73．5%(x^2=1．81,P＞0．05)。局部早期(T1～T2期)和局部晚期(T3～T4期)病变淋巴结转移分布间差异无统计学意义。结论鼻咽癌淋巴结转移率高,以咽后淋巴结最多见,跳跃性转移率低。不同T分期淋巴结转移率无差别,鼻咽癌淋巴结转移的分布与T分期无关。

Objective To explore the distribution rule of metastatic lymph node in nasopharyngeal carcinoma （NPC） by magnetic resonance imaging （MRI）. Methods 315 histopathologically proved NPC patients were studied retrospectively. All patients had had their nasopharynx scanned by MRI with plain and contrast enhanced sequences. The distribution of lymph node was divided into six cervical levels plus retropharyngeal nodes（RN） according to RTOG guidelines proposed in 2003. Results 254 out of 315 patients （80.6%） had lymph node involvement, with 81 in the right neck alone, 72 left neck alone, and 101 both necks; 73 in RN alone, 21 neck node alone, and 160 both necks and RN node. Skip metastasis was found in only 4 patients （ 1.6% ）. There was significant difference in RN metastasis between the primary tumor being located merely on the superior/posterior wall and lateral wall （78% vs 49% , P 〈0.01 ）. The incidence of lymph node metastasis in T1, T2, T3 and T4 patients was 73.5% ,91.2% ,71.9% ,73.5% （P 〉0.05） , respectively, without significant difference between early or advanced T stage in node distribution （P 〉 0.05）. Conclusions The incidence of lymph node metastasis is high in nasopharyngeal carcinoma, with retropharyngeal node being the most commonly involved, but the incidence of skip metastasis is very low. There is no significant difference between T stage and the incidence of lymph node metastasis. So is the distribution of metastatic node.