多层螺旋CT和正电子发射计算机体层成像-CT评价乳腺癌腋窝淋巴结状态的对照研究

Comparative analysis of multi-slice spiral CT and positron emission tomography-CT in evaluation of axillary lymph nodes in breast cancer patients

目的探讨多层螺旋CT（MSCT）、正电子发射计算机体层成像-CT（PET-CT）评价乳腺癌腋窝淋巴结转移的价值。方法手术病理证实的乳腺癌患者40例均行MSCT增强扫描，其中的13例行^18F脱氧葡萄糖（^18F-FDG）PET—CT检查。3名医师分别采用5分评价法对CT图像中淋巴结进行综合评分，≥3分时该淋巴结记录为阳性（淋巴结有转移），〈3分时记录为阴性。采用目测法和半定量分析法相结合分析PET—CT图像所显示的淋巴结，分别作阴、阳性记数。将PET-CT、增强MSCT对腋窝淋巴结的检出结果与手术病理结果进行对照。用精确概率法对结果进行统计学分析。结果40例患者行MSCT检查共检出腋窝淋巴结158枚，其中CT阳性计数91枚，阴性计数67枚；术后病理阳性99枚，阴性59枚。13例行PET-CT检查者共检出腋窝淋巴57枚，PET-CT显像阳性39枚，阴性18枚；术后病理阳性39枚，阴性18枚。CT对腋窝淋巴结转移定性的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为88．89％、94．91％、91．14％、96．70％和83．58％；PET-CT分别为97．44％、94．44％、96．49％、97．44％和94．44％。CT与PET-CT对腋窝淋巴结转移定性的敏感性、特异性、准确性和阳性预测值差异无统计学意义（P〉0．05）；但PET-CT的阴性预测值高于MSCT，二者之间差异有统计学意义（P〈0．05）。结论CT、PET-CT都能准确评价乳腺癌腋窝淋巴结的状态，但PET-CT检测腋窝淋巴结的阴性预测值高于MSCT，PET-CT能在术前更准确评价乳腺癌患者腋窝淋巴结状态。

Objective To evaluate and compare spiral CT and positron emission tomography-CT （PET-CT） in characterization of of axillary lymph nodes in breast cancer patients. Methods Forty patients with pathologically proven breast cancer underwent contrast-enhanced spiral CT of the breast and axilla, 13 of them also underwent PET-CT examination. One hundred and fifty-eight axillary lymph nodes were found in the 40 patients through contrast enhanced spiral CT, while 57 lymph nodes were found in the 13 patients through PET-CT. Three radiologists rated the lymph nodes found in CT images on a five-point scale. If the score was equal to or greater than 3, it was defined as positive （metastatic） , otherwise negative. Visual observation and semiquantitative analysis were used to classify lymph nodes in PET-CT images. The results of spiral CT observation and PET-CT observation of lymph nodes were compared with pathological results. The relative value of CT and PET-CT was analyzed. Exact probability statistics were employed. Results One hundred and fifty eight lymph nodes of 40 patients were detected by spiral CT, 91 of them were diagnosed as positive and 67 as negative Among the lymph nodes found in spiral CT, 99 were positive and 59 were negative pathologicall. A total of 57 lymph nodes were found by PET-CT. Thirty-nine of them were defined as positive and 18 as negative. Among the lymph nodes found in PET-CT, 39 were positive and 18 were negative pathologically. The sensitivity, specificity, accuracy, positive and negative predictive values in CT prediction in axillary lymph nodes metastases were 88.89% , 94.91% , 91.14% , 96.70%, and 83.58%, respectively. The sensitivity, specificity, accuracy, positive and negative predictive values in PET-CT prediction in axillary lymph nodes metastases were 97.44%, 94.44%, 96. 49% , 97.44%, and 94. 44% , respectively. PET-CT had no significant difference with spiral CT in sensitivity, accuracy, positive and negative predictive values for detection of axillary lymph nodes in breast cancer. But there was significant difference between PET-CT and CT in negative predictive value （P 〈 0. 05）. Conclusions Both helical CT and PET-CT were the efficient methods in predicting the axillary lymph node status in breast cancer patiens. The negative predictive value of PET-CT was higher than that of helical CT. PET-CT has a better predictive ability than CT for the presurgical evaluation for breast cancer patients.