基于MRI的3100例鼻咽癌淋巴结转移规律分析

目的 应用MRI研究鼻咽癌淋巴结转移规律,为IMRT提供颈部照射范围依据。方法 前瞻分析2010—2013年间具有MRI检查的 3100例初治鼻咽癌患者资料。由鼻咽癌多学科综合治疗组阅片,分析淋巴结转移。淋巴结位置按RTOG分区2003版评判。结果 全组淋巴结转移占86.42%(2679/3100),其中分布在咽后外侧组 2012例 (64.90%,其中 6例 同时位于中央组), Ⅱ341例 (75.52%,其中 492例 淋巴结上界至C1一半水平、115例 到达颅底水平), Ⅱ798例 (58.00%),Ⅲ区 1184例 (38.19%),Ⅳ区 350例 (11.29%,其中 28例 下界超出RTOG规定的范围),Ⅴ区 995例 (32.10%,其中 91例 超出规定范围),Ⅰb 区 115例 (3.71%),腮腺区域 40例 (1.29%,均伴随同侧广泛淋巴结转移,且淋巴结总数≥6个)。只 6例 发生跳跃性转移(0.19%)。结论 ①鼻咽癌中央组咽后淋巴结转移较为罕见;②Ⅱ区淋巴结上界为颅底水平更合适;③鼻咽癌淋巴结转移从上至下规律性发展;④Ⅳ、Ⅴ区有转移时淋巴结可能超出RTOG规定范围;⑤同侧淋巴结广泛转移时可能出现腮腺区累及。

Patterns of lymph node metastases from nasopharyngeal carcinoma:an analysis of 3100 patients based on MRI

Objective To investigate the patterns of lymph node metastases from nasopharyngeal carcinoma (NPC) based on magnetic resonance imaging (MRI) and to provide a basis for neck irradiation field in intensity-modulated radiation therapy. Methods From 2010 to 2013, 3100 patients newly diagnosed with NPC who underwent MRI were analyzed. All images were evaluated by the multi-disciplinary treatment group for NPC to analyze lymph node metastases. The locations of lymph nodes were determined by the RTOG consensus guidelines published in 2003. Results Of 3100 patients, 2679(86.42%) had lymph node metastases;the detailed distribution was as follows:lateral retropharyngeal region (2012 patients, 64.90%;6 patients were also in the medial group), level Ⅱ_b (2341 patients, 75.52%;492 had the upper border reaching half of C₁ vertebra and 115 had the upper border reaching the skull base), level Ⅱ_a (1798 patients, 58.00%), level Ⅲ(1184 patients, 38.19%), level Ⅳ (350 patients, 11.29%;28 had the lower border beyond the RTOG recommended boundary), level Ⅴ (995 patients, 32.10%;91 had the lymph nodes beyond the RTOG recommended boundary), level Ⅰ_b (115 patients, 3.71%), and parotid region (40 patients, 1.29%). Extensive ipsilateral lymph node metastases were seen in patients with lymph nodes metastases in levels Ⅳ and Ⅴ, and the total numbers of involved nodes were ≥6 and 7. Skip metastasis occurred in 6 patients (0.19%). Conclusions Metastases to retropharyngeal lymph nodes are seen mainly in the lateral group but rarely in the medial group. The upper border of level Ⅱ lymph nodes should be the skull base. Lymph node metastases from NPC are in an orderly manner, and skip metastasis is rarely seen. When level Ⅳ/Ⅴ lymph nodes are involved, there might exist metastases beyond the RTOG recommended boundary. In case of extensive ipsilateral lymph node metastases, the parotid region might be involved.