非小细胞肺癌区域转移淋巴结包膜外侵对临床靶区勾画的价值

Clinical importance of defining the clinical target volume in detection of microscopic extracapsular extension of regional metastatic nodes by pathology in non-small cell lung cancer

目的通过对非小细胞肺癌（NSCLC）患者区域转移淋巴结包膜外侵（ECS）的研究，探讨ECS在淋巴结临床靶体积（CTV）勾画中的意义。方法回顾分析101例接受手术治疗的NSCLC患者，术后常规行病理检查，确定原发肿瘤大小、病理类型及肿瘤分级、区域淋巴结转移状况及淋巴结ECS的最大侵袭距离。研究NSCLC区域淋巴结ECS与淋巴结大小、解剖位置、原发肿瘤部位、临床分期、病理类型及肿瘤分级的关系。结果640个转移淋巴结中有ECS者214个，占33.4％。转移淋巴结发生ECS与肿瘤分级明显相关（r=0．142，P＜0．05）。鳞癌、腺癌、腺鳞癌三组淋巴结侵袭范围差异无统计学意义（F=0．88，P＞0．05）；鳞癌淋巴结95％的侵袭范围为5．92mm，腺癌为5．00mm，腺鳞癌为6．50mm。结论NSCLC有区域淋巴结转移者，在三维适形放疗或调强放疗时需要酌情考虑CTV-N扩充区。

Objective As generally known, defining the margin of clinical target volume （CTV） is very important for three-dimensional conformal radiotherapy（3DCRT） and intensity-modulated radiation therapy（IMRT） . In this study, we tried to determine the optimal clinical target volume margin around the gross regional nodal tumor volume in patients with non-small cell lung cancer（NSCLC） by assessing microscopic tumor extension beyond the regional lymph node capsule examined by pathology after the lesions had been resected. Methods From January 2003 to December 2004, 101 operated NSCLC patients were reviewed retrospectively. All patients had had routine pathology examination after surgery with the primary tumor size and the depth of extracapsular spread （ECS） lymph nodes were measured. Results 214 had ECS in a total of 640 metastatic lymph nodes. There was no statistical significance among different pathological types （ F = 0.88, P 〉 0.05 ）. Taking 95% of local microscopic extension into account, a margin of 5.92 mm and 5.00 mm must be allowed for squmous cell carcinoma and adenocarcinoma, respectively. Conclusion In the target volume defining for 3DCRT and IMRT, clinical target ＋ volume-N（CTV-N） needs to be considered carefully in the regional metastatic lymph nodes of non-small cell lung cancer.