Division of Thoracic Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
J Chin Med Assoc. 2012 May;75(5):203-8. doi: 10.1016/j.jcma.2012.04.004. Epub 2012 May 12.
Positron emission tomography combined with computed tomography (PET-CT) is important in the assessment and workup of lung cancer staging. However, inconsistencies between clinical image results obtained and pathologic findings of surgical specimens are still very common, particularly in patients with clinical early stage lung cancer. We sought to clarify the role of PET-CT in predicting mediastinal lymph node status preoperatively in clinical early stage lung cancer patients.
The cases were collected retrospectively from January 2008 to February 2009. All patients were good surgical candidates, and clinically early-stage during the pre-op evaluation, which included CT, PET scan, and cardiopulmonary tests. All patients underwent surgery, with complete pathological evaluation of mediastinal lymph node (LNs). The pathological status and PET Standardized uptake value (SUV)(max) of mediastinal LNs were collected to calculate the ROC curve, and to determine the best cut-off value of PET SUV(max). Other cofactors, including sex, tumor size, tumor SUV(max), histology type, and lobar distribution, were analyzed utilizing correlation study, Chi-square test, and t-test for significance.
A total of 83 patients were enrolled into the study. The majority of the cases were in pathological early stage (Stage I: 67.5%, Stage II: 12%). The cut-off point of mediastinal LN SUV(max) was 1.6 calculated by receiver operating characteristic (ROC) curve (sensitivity: 40%, specificity: 88.7%, negative predictive rate: 95.1%). The hilar LN SUV(max) was found to have a poor correlation to the final pathologic status of hilar nodes with insignificant p value (0.487). Tumor SUV(max) and increased hilar LN uptake (SUV(max) > 2.0) were found to be significantly correlated with the pathologic status of mediastinal LNs. The false positive rates by PET-CT scan in N1 and N2 nodes were 70% and 78%, respectively, primarily due to inflammatory process (as anthracosis the leading cause).
Integrated PET-CT is a useful tool for predicting the negativity of mediastinal LN status pre-operatively in clinically early stage (Stages I and II) lung cancer but may be relatively inaccurate in predicting hilar LN status and largely confounded by false positives caused by inflammatory process.
正电子发射断层扫描结合计算机断层扫描（PET-CT）在肺癌分期评估和研究中非常重要。然而，临床影像结果与手术标本病理发现之间的不一致仍然非常普遍，尤其是在临床早期肺癌患者中。我们旨在阐明 PET-CT 在预测临床早期肺癌患者术前纵隔淋巴结状态中的作用。
本研究病例为 2008 年 1 月至 2009 年 2 月期间回顾性收集的。所有患者均为良好的手术候选者，且在术前评估时处于临床早期阶段，评估包括 CT、PET 扫描和心肺检查。所有患者均接受手术，并对纵隔淋巴结（LN）进行完整的病理评估。收集纵隔 LN 的病理状态和 PET 标准化摄取值（SUV）（最大值），以计算 ROC 曲线，并确定 PET SUV（最大值）的最佳截断值。利用相关性研究、卡方检验和 t 检验分析其他协变量，包括性别、肿瘤大小、肿瘤 SUV（最大值）、组织学类型和肺叶分布。
共纳入 83 例患者。大多数病例处于病理早期阶段（I 期：67.5%，II 期：12%）。ROC 曲线计算出纵隔 LN SUV（最大值）的截断点为 1.6（敏感性：40%，特异性：88.7%，阴性预测率：95.1%）。结果发现，肺门 LN SUV（最大值）与肺门淋巴结的最终病理状态相关性较差，p 值无统计学意义（0.487）。肿瘤 SUV（最大值）和肺门 LN 摄取增加（SUV（最大值）>2.0）与纵隔 LN 的病理状态显著相关。PET-CT 扫描在 N1 和 N2 淋巴结中的假阳性率分别为 70%和 78%，主要是由于炎症过程（如炭末沉着症是主要原因）所致。
综合 PET-CT 是一种有用的工具，可用于预测临床早期（I 期和 II 期）肺癌患者纵隔 LN 状态的阴性，但在预测肺门 LN 状态方面可能相对不准确，且主要受到炎症过程引起的假阳性的干扰。
