Lee Benjamin Enoch, Redwine Jonathon, Foster Cameron, Abella Elma, Lown Teri, Lau Derick, Follette David
Division of Cardiothoracic Surgery, University of California at Davis, Sacramento, Calif 95817, USA.
J Thorac Cardiovasc Surg. 2008 Mar;135(3):615-9. doi: 10.1016/j.jtcvs.2007.09.029. Epub 2008 Jan 11.
Accurate pretreatment staging in non-small cell lung cancer remains tantamount in formulating an appropriate treatment plan. The maximum standardized uptake value obtained with integrated fluorodeoxyglucose-positron emission tomography/computed tomography has been proposed to be a predictor of malignancy in mediastinal lymph nodes. A recent study has also suggested that accuracy of integrated fluorodeoxyglucose-positron emission tomography/computed tomography might be improved by increasing the maximum standardized uptake value used for calling a lymph node positive from 2.5 to 5.3. We tested the hypotheses that the maximum standardized uptake value is a predictor of individual lymph node metastasis in non-small cell lung cancer and that pathologic staging with mediastinoscopy might not be necessary in patients with a maximum standardized uptake value of less than 5.3 in their mediastinal lymph nodes.
This is a retrospective review of 765 lymph nodes sampled from 110 patients in a single institution with biopsy-proved non-small cell lung cancer. All patients underwent integrated fluorodeoxyglucose-positron emission tomography/computed tomography before biopsy or resection of their mediastinal lymph nodes. Surgical staging was the reference standard. All N2 lymph nodes were individually assessed according to station. Data were analyzed by using the Pearson chi(2) test.
Twenty-one (19%) of 110 patients had N2 disease, and a total of 765 N2 lymph nodes were pathologically examined. The mean and median maximum standardized uptake values for N2 nodes with metastatic disease were 9.2 (95% confidence interval, 7.0-11.4) and 7.2 (range, 2.2-25.8), respectively. For benign N2 nodes, the mean and median maximum standardized uptake values were 1.5 (95% confidence interval, 1.4-1.6) and 1.0 (range, 1.0-9.6), respectively (P < .05). When integrated fluorodeoxyglucose-positron emission tomographic/computed tomographic scans were reinterpreted by using a maximum standardized uptake value of 5.3 as a cutoff for malignancy, sensitivity decreased from 93% to 81% (P = .15), specificity increased from 86% to 98% (P < .01), positive predictive value increased from 22% to 64% (P < .01), negative predictive value was unchanged at 99%, and overall accuracy of integrated positron emission tomography/computed tomography increased from 87% to 97% (P < .01).
The maximum standardized uptake value is a predictor of individual lymph node metastasis in non-small cell lung cancer. Accuracy of integrated positron emission tomography/computed tomography is significantly improved by using a maximum standardized uptake value of 5.3 to assign malignancy, thereby dramatically decreasing the number of false-positive results. More importantly, these results suggest that some patients with non-small cell lung cancer with a maximum standardized uptake value less than 5.3 in their N2 lymph nodes might be able to forego mediastinoscopy and proceed directly to thoracotomy. This represents a significant change in the current management of standardized uptake value-positive mediastinal lymph nodes in non-small cell lung cancer.
在非小细胞肺癌中，准确的治疗前分期对于制定合适的治疗方案至关重要。有人提出，通过氟脱氧葡萄糖-正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）获得的最大标准化摄取值可作为纵隔淋巴结恶性肿瘤的预测指标。最近的一项研究还表明，将判定淋巴结为阳性的最大标准化摄取值从2.5提高到5.3，可能会提高FDG-PET/CT的准确性。我们检验了以下假设：最大标准化摄取值是非小细胞肺癌单个淋巴结转移的预测指标；对于纵隔淋巴结最大标准化摄取值小于5.3的患者，可能无需进行纵隔镜病理分期。
这是一项对单一机构中110例经活检证实为非小细胞肺癌患者的765个淋巴结进行的回顾性研究。所有患者在纵隔淋巴结活检或切除前均接受了FDG-PET/CT检查。手术分期为参考标准。所有N2淋巴结均按部位进行单独评估。采用Pearson卡方检验分析数据。
110例患者中有21例（19%）患有N2期疾病，共对765个N2淋巴结进行了病理检查。发生转移的N2淋巴结的最大标准化摄取值的均值和中位数分别为9.2（95%置信区间，7.0 - 11.4）和7.2（范围，2.2 - 25.8）。对于良性N2淋巴结，最大标准化摄取值的均值和中位数分别为1.5（95%置信区间，1.4 - 1.6）和1.0（范围，1.0 - 9.6）（P < 0.05）。当将最大标准化摄取值5.3作为恶性肿瘤的临界值重新解读FDG-PET/CT扫描结果时，敏感性从93%降至81%（P = 0.15），特异性从86%升至98%（P < 0.01），阳性预测值从22%升至64%（P < 0.01），阴性预测值保持在99%不变，FDG-PET/CT的总体准确性从87%升至97%（P < 0.01）。
最大标准化摄取值是非小细胞肺癌单个淋巴结转移的预测指标。使用最大标准化摄取值5.3判定恶性肿瘤可显著提高FDG-PET/CT的准确性，从而大幅减少假阳性结果的数量。更重要的是，这些结果表明，一些N2淋巴结最大标准化摄取值小于5.3的非小细胞肺癌患者可能无需进行纵隔镜检查，可直接进行开胸手术。这代表了非小细胞肺癌中目前对标准化摄取值阳性纵隔淋巴结管理的重大改变。
