Background and objective: Positron emission tomography (PET) is used increasingly in staging of non-small cell lung cancer (NSCLC) as a non-invasive tool. However, the role of PET in mediastinal lymphatic staging of NSCLC is not clear. The aim of this study was to demonstrate the efficacy of mediastinoscopy in determining mediastinal lymphatic metastasis in cases of positive PET finding.
Methods: We performed PET preoperatively in 68 patients with clinically operable NSCLC between 2003 and 2008. Mediastinal lymphatic defined as metastasis by PET (SUV(max) > 2.5) was recorded. Mediastinoscopy being performed initially in all patients. Involvement of mediastinal lymph nodes was verified to compare the sensitivity and specificity of mediastinoscopy and the related PET results.
Results: From 2003 to 2008, 61 mediastinoscopy were performed. There were 38 men and 23 women, aged from 41 to 81 years (mean 60 years). Localization of the tumor was right lung in 41 patients and left lung in 20 patients. After the operation, 45 patients were demonstrated to have N2 or N3 disease. Ten patients with N3 mediastinal metastasis for chemotherapy, 38 patients with N2 mediastinal metastasis for neuadjuvant chemotherapy while lung resection and systemic mediastinal lymphatic dissection through thoracotomy was performed in the remaining 16 patients with no mediastinal metastasis. The positive prediction value of PET scan was 73.8% (45/61). The sensitivity, specificity, accuracy, positive prediction value and negative prediction value in diagnosis of metastasis of mediastinal lymph nodes were 93.8% (45/48), 100% (13/13), 95.1% (58/61), 100% (45/45), 81.3% (13/16) for mediastinoscopy, respectively.
Conclusion: PET results do not provide acceptable accuracy rates. Mediastinoscopy still remains the gold standard for mediastinal staging of NSCLC.
背景与目的: 正电子发射断层成像检查（positron emission tomography, PET）作为非小细胞肺癌无创分期的手段有逐年增加的趋势，但是它在纵隔淋巴结分期中的作用尚不明了。本文探讨了电视纵隔镜检查术在PET肺癌纵隔淋巴结显像阳性病例中的临床价值。
方法: 2003年11月-2008年11月，对宣武医院收治的术前PET检查提示纵隔淋巴结转移的肺癌患者行电视纵隔镜检查术。对纵隔淋巴结进行病理学检查，病理来自纵隔镜或开胸清扫的纵隔淋巴结，分析纵隔镜诊断纵隔淋巴结转移的敏感性、特异性等。
结果: 本组61例肺癌患者中，男38例，女23例，平均年龄60岁（年龄41岁-81岁）。其中右肺癌41例，左肺癌20例。45例肺癌患者手术病理证实有纵隔淋巴结转移，其中10例N3的患者接受化疗，38例N2的患者给予2个周期的新辅助化疗，并根据检查结果确定是否接受开胸手术。16例无纵隔淋巴结转移的患者翻身行开胸探查、肺癌切除、纵隔淋巴结清扫术。PET的阳性预测值为73.8%（45/61）。电视纵隔镜在肺癌纵隔淋巴结分期中的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为93.8%（45/48）、100%（13/13）、95.1%（58/61）、100%（45/45）、81.3%（13/16）。
结论: PET在肺癌纵隔淋巴结分期中的阳性预测值较低，电视纵隔镜仍然是肺癌纵隔淋巴结分期的金标准。