PET/CT在非小细胞肺癌放射治疗勾画靶区中的价值

Value of PET / CT in design of irradiation target volume in patients with non-small cell lung cancer

目的采用PET/CT分析非小细胞肺癌（non-small cell lung cancer，NSCLC）纵隔淋巴结转移特点，为放疗患者勾画靶区提供参考依据。方法375例初治NSCLC患者在治疗前行18F-FDG PET/CT扫描，对不同原发灶部位、分期及病理类型发生纵隔淋巴结转移情况进行统计分析。结果PET/CT结果显示，207例右肺NSCLC纵隔淋巴结转移率由高到低依次为同侧肺门、4R、7、5、2R、10～11L、6区；168例左肺NSCLC纵隔淋巴结转移率依次为同侧肺门淋巴结、5、7、6、4L、4R、10～11R区。中肺和下肺NSCLC的7区转移率显著高于上肺。鳞癌和腺癌纵隔淋巴结转移差异无统计学意义（P〉0.05）。随着患者T分期增加，更容易发生纵隔淋巴结转移。375例NSCLC患者中有88例发生了跳跃式转移，占23.5%。191个跳跃转移区中，4R、7、5、6、2R占有较高比例。纵隔淋巴结跳跃式转移与NSCLC原发灶部位、病理类型及分期无相关性（P〉0.05）。结论PET/CT提示左右肺NSCLC患者纵隔淋巴结转移高危区不同，建议右肺NSCLC放疗靶区应包括10～11R、4R、7、5区；左肺NSCLC放疗靶区应包括10～11L、5、7、6、4L、4R区。

Objective To obtain reference data for designing rational irradiation target volume by the characteristics of mediastinal lymph node metastasis in non-small cell lung cancer （NSCLC） patients by positron emission tomography/computed tomography （PET/CT）. Methods The 18F-FDG PET/CT data of 375 NSCLC patients freshly diagnosed by pathology in our hospital from 2012 to 2015 before treatment were collected. The distribution characteristics of mediastinal lymph node metastasis with different lesion location, clinical stage, and pathologic types were analyzed. Results PET/CT scanning indicated that in the 207 patients with right lung NSCLC, the metastasis incidences of mediastinal lymph nodes were decreased as the following order, ipsilateral hilar nodes, 4R, 7, 5, 2R, 10~11L and 6. And for the 168 patients with left lung NSCLC, the highest metastasis incidence of mediastinal lymph nodes was the ipsilateral hilar nodes, followed by 5, 7, 6, 4L, 4R and 10~11R. The metastatic rate of zone 7 area was significantly higher in inferior and middle lobe lung than in the superior lobe lung for the patients. There was no significant differences in the mediastinal lymph node metastasis between the squamous carcinoma and adenocarcinoma （P〉0.05）. With the increasing of T stage, the patients were prone to mediastinal lymph node metastasis. There were 88 patients having skip metastasis among the 375 patients, accounting for 23.5%. In the 191 skip metastasis areas, 4R, 7, 5, 6 and 2R had higher percentages. Mediastinal lymph nodes metastasis had no correlation with location, pathological type and stage in primary lung lesion P〉0.05）. Conclusion PET/CT results indicate that the high risk metastatic areas are different in the right and left NSCLC, and clinical irradiation target volume should include zones 10~11R, 4R, 7 and 5 for the patients of right lung NSCLC, and 10~11L, 5, 7, 6, 4L and 4R.