正电子发射体层成像在肺癌诊治中的作用

目的探讨正电子发射体层成像（PET）在肺癌诊治中的作用。方法收集1998年9月1日至2000年3月1日期间就诊的肺癌或拟诊为肺癌的患者，均行PET及胸腹部CT、骨显像检查。结果共收集88例患者，其中肺癌患者68例(77.3%)，良性疾病者20例(22.7%)。CT与PET共发现125个肺内病灶，其中恶性病灶80个（64.0%），良性病灶45个（36.0%），恶性病灶的标准摄取比（SUR）值明显高于良性病灶。PET诊断肺癌的敏感性、特异性与病灶是否经过放化疗无关，但与病灶大小相关。对肺内病灶PET所见及SUR值诊断的特异性及准确性均高于CT，其中PET诊断的敏感性、特异性和准确性分别为95.0%、95.6%及95.2%；SUR值诊断分别为65.0%、91.1%及74.4%。SUR值诊断直径≥1.5cm的肺内病灶的准确性高于直径＜1.5cm的病灶。在诊断肺癌肺门淋巴结、纵隔淋巴结、远处淋巴结转移中，PET敏感性及准确性均显著高于CT。SUR值与细胞分化程度无关；小细胞肺癌经过放化疗后SUR值显著下降。结论PET在判断肺内病灶的良恶性程度上有优势，且能准确判断肺癌淋巴结转移情况。对直径<1.5cm的病灶及放化疗后的病灶，PET诊断的准确性高。

Application of positron emission tomography in diagnosis and treatment of lung cancer

OBJECTIVE: To determine the usefulness of positron emission tomography(PET) with fluoro-2-deoxyglucose (FDG-PET) in lung cancer. METHODS: Patients who presented between September 1999 and March 2000 with lung cancer or indeterminate lung lesions on chest CT scan were enrolled and underwent FDG-PET scanning. RESULTS: Of the 88 patients, 68 (77.3%) patients had malignancy and 20(22.7%) patients had a benign lesion. Of the 125 lung lesions, 80(64.0%) malignant lesions had a median standard uptake ratio (SUR) of 2.8(range 0-12.0), while 45(36.0%) benign lesions had a median SUR of 0(range 0-3.7). There was significant difference between the two groups. The diagnostic sensitivity and specificity of PET imaging for lung lesions were associated with the size of lesions but not with radiation or chemotherapy given before. The diagnostic specificity and accuracy of PET for lung lesions were significantly higher than those of CT scan. The sensitivity, specificity and accuracy of SUR method were 65.0%, 91.1% and 74.4% respectively and those of PET visual analysis were 95.0%, 95.6% and 95.2% respectively. The accuracy for lung lesions > or = 1.5 cm with SUR method was higher than that of lesions < 1.5 cm, being 93.8% and 62.3% respectively. The diagnostic sensitivity and accuracy of PET visual analysis for lymph node metastasis were significantly higher than those of CT scan. SUR was not correlated with the degree of cell differentiation, but it decreased significantly in small cell lung cancer after radiation or chemotherapy. CONCLUSIONS: PET is of advantage to the evaluation of lung lesions and diagnosis of lymph node metastasis in lung cancer. PET visual analysis is recommended in lung lesions after radiation or chemotherapy or with size < 1.5 cm in diameter.