Mediastinal lymph node evaluation by computed tomographic scan in lung cancer

BACKGROUND: Computed tomography (CT) has been widely used for preoperative mediastinal lymph node evaluation in lung cancer. But its accuracy has remained controversial. We studied the predictability of N-staging by CT scan. METHODS: From 1981 to 1996, 546 patients had preoperative CT scan and underwent a surgical resection with mediastinal lymph node dissection for primary pulmonary adenocarcinoma and squamous cell carcinoma. Nodes larger than 1.0 cm at short axis were considered abnormal. The discrepancy between clinical and pathologic findings in N factor was analyzed. RESULTS: Sensitivity (ST), specificity (SP) and accuracy (AC) were 33.0%, 90.4% and 78.9%, respectively. No statistically significant difference in the results is detected for individual years or types of scanning device. There were statistically significant differences as follows: ST and SP by histologic type, SP by gender, SP and AC by tumor size, SP by Brinkman index, ST by tumor location, and AC by serum CEA value. CONCLUSIONS: We should pay attention to false positive nodes in heavy smokers (or males), and positive nodes in adenocarcinoma, tumor larger than 3 cm or rising of serum CEA value, regardless of negative lymph node on CT scan.     

The role of computed tomographic scanning in diagnosing mediastinal node involvement in non-small cell lung cancer

OBJECTIVES: The reliability of computed tomographic scanning in evaluating mediastinal node involvement is controversial because of the high false result rate. We attempted to identify significant factors responsible for false-positive and false-negative scans. METHODS: From August 1992 through April 1997, 401 patients with lung cancer who underwent major lung resection and systematic lymph node dissection were enrolled in this study. We retrospectively examined mediastinal node size, tumor location, maximum tumor dimension, the presence or absence of obstructive pneumonia, atelectasis, pulmonary fibrosis, and lymph node calcification on contrast-enhanced computed tomographic scans. We identified clinical and radiologic factors responsible for the false results by using univariate and multivariable analysis. RESULTS: Central tumor location proved to be a significant factor of false-positive scans. Elevated carcinoembryonic antigen level and larger tumor dimension were significant factors of false-negative scans. In patients with a peripheral tumor smaller than 40 mm and normal levels of serum carcinoembryonic antigen, sensitivity, specificity, positive predictive value, and negative predictive value were 6%, 93%, 8%, and 90%, respectively. The reliability of computed tomographic scanning in this low-risk subgroup was high in detecting N0-1 disease but low in diagnosing N2 disease. CONCLUSION: It is not possible to accurately diagnose N2 disease by using lymph node size on computed tomographic scanning alone, especially in patients with a central tumor, an elevated serum carcinoembryonic antigen level, or a tumor of 40 mm or larger. A preoperative invasive staging procedure is indicated in these populations and may not be indicated in the population with normal computed tomographic scan results without any of these risk factors.     

Meta-analysis of positron emission tomographic and computed tomographic imaging in detecting mediastinal lymph node metastases in nonsmall cell lung cancer

A systematic review was undertaken to select studies that compared the accuracy of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography with computed tomographic imaging in detecting mediastinal lymph node metastases in patients with nonsmall cell lung cancer. Two authors selected relevant articles according to predefined criteria. With a meta-analytic method, summary receiver operating characteristic curves were constructed. The point on the receiver operating characteristic curve with equal sensitivity and specificity for 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography was Q* = 0.90 (95% confidence interval [CI], 0.86 to 0.95). For computed tomography it was 0.70 (95% CI, 0.65 to 0.75). The difference was highly significant (p < 0.0001). We conclude that 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography is more accurate than computed tomography in detecting mediastinal lymph node metastases.     

肺鳞癌、腺癌纵隔淋巴结转移的特点

目的 研究原发肺鳞癌及腺癌纵隔淋巴结转移特点,探讨临床意义.方法 对353例原发肺癌施行同侧纵隔淋巴结廓清术,病理检测淋巴结转移频度.结果 清除淋巴结2380组,平均每例6.74组.N2 淋巴结转移率16.2%.T1、T2、T3间淋巴结转移率差异有统计学意义(P<0.01).N2转移率在鳞癌、腺癌分别为30.1%、44.1%.64.2% 鳞癌N2转移为某一组淋巴结,腺癌3组以上转移者46.2%.上叶肺癌跨区域N2转移占15.1%,下叶(包括中叶)肺癌跨区域转移占53.1%.跳跃式转移占N2转移的53.7%.结论 肺鳞癌及腺癌纵隔淋巴结转移具有多发性、跳跃性及跨区域性特点.     

Pathological assessment of mediastinal lymph nodes in lung cancer: implications for non-invasive mediastinal staging.

BACKGROUND: The use of computed tomography in mediastinal staging of lung cancer relies on the premiss that malignant lymph nodes are larger than benign ones. This hypothesis was tested by linking node size and presence or absence of malignancy and looking at factors possibly influencing the size of benign nodes. METHODS: All accessible mediastinal lymph nodes were taken from 56 consecutive patients with lung cancer who underwent thoracotomy. Nodes were measured and histologically examined. Resected cancer bearing lung from 44 of these patients was assessed for degree of acute and chronic inflammation. RESULTS: Lymph node size was not significantly related to the presence of metastatic disease, 58% of malignant and 43% of benign lymph nodes measuring over 15 mm. Similarly, there was no statistically significant relation between size of lymph nodes and the likelihood of malignancy, 20% of lymph nodes of 10 mm or more but also 15% of those less than 10 mm being malignant. Thresholds of 15 and 20 mm showed similar results. The maximum size of benign lymph nodes was significantly greater in those patients with histological evidence of acute pulmonary inflammation than in those without. CONCLUSIONS: The study shows that in patients with lung cancer (1) malignant mediastinal lymph nodes are not larger than benign nodes; (2) small mediastinal lymph nodes are not infrequently malignant; and (3) benign adenopathy is more common in patients with acute pulmonary inflammation.     

Surgical treatment for lung cancer with metastasis to mediastinal lymph nodes.

A series of cases of lung cancer were analyzed, with particular attention to the relationship between the presence of lymph node metastases and the prognosis for surgical intervention. The cases are classified into four clinical stages and a detailed classification of histologically proved lymph node metastasis and pleural involvement is presented. Results indicate that the presence of mediastinal lymph node metastasis, especially in cases with squamous-cell carcinoma and negative subcarinal lymph node, does not contraindicate surgical treatment.     

Computed tomography for evaluation of mediastinal lymph nodes in lung cancer: correlation with surgical staging

Computed tomography (CT) of the chest (late model) was done preoperatively in 56 candidates for resection of lung cancer. Precise borders for each node region were defined by the American Thoracic Society modification of the classification of the American Joint Committee for Cancer Staging and were used to "map" nodes seen on CT and nodes removed surgically. Metastatic involvement of mediastinal nodes was proven by mediastinoscopy in 11 patients; nodes were removed from multiple regions at thoracotomy in 45 patients. The mediastinum was clearly delineated by CT in 46 patients with determinate scans and was judged normal in 32 (CT-negative scans) and abnormal in 14 (CT-positive scans). A node was considered metastatically involved if it measured greater than 1.5 cm in diameter. Positive nodes were found at surgical staging in 3 of 32 patients with CT-negative scans and in all patients with CT-positive scans. Thus, for the 46 patients with determinate scans, sensitivity was 82%, specificity was 100%, and accuracy (true positive and true negative) was 93%. The high accuracy of CT in these patients suggests that mediastinoscopy is not necessary before thoracotomy in the patient with a CT-negative scan, but that for the patient with a CT-positive or CT-indeterminate scan, the indications for mediastinoscopy remain the same.     

Study of mediastinal lymph nodes in lung cancer using transesophageal ultrasonography]

Evaluation of mediastinal lymph nodes in patients with lung cancer is fundamental for their treatment and prognosis. Chest computed tomography (CT) is presently the most utilized diagnostic modality. In recent years endoscopic ultrasound (EUS) is being employed for this purpose. We retrospectively compared the results of CT and EUS staging of 35 selected patients with postsurgical stage. A total of 175 lymph node sites were examined. Results CT vs EUS were as follows: specificity 92% vs 98%, sensitivity 88% vs 84%, positive predicted accuracy 80% vs 96%, negative predicted accuracy 95% vs 94%, overall accuracy 92% vs 95%. The region most accessible by EUS evaluation were the paraesophageal lymph nodes; the most difficult were the right superior mediastinal nodes which cannot be imaged for anatomic reasons. EUS not only allows one to arrive at correct diagnosis with less false positive results, but also permits evaluation of lymph nodes which are not enlarged. We think that EUS, in combination with CT, is an appropriate modality for staging of mediastinal lymph nodes in patients with lung cancer.     

Imprint cytology for detecting metastasis of lung cancer in mediastinal lymph nodes

Background

Lymph node metastasis of lung cancer has been evaluated with histologic examination. We studied the usefulness of cytologic diagnosis for detecting metastasis of lung cancer in mediastinal nodes.

Methods

Five hundred twelve stations of mediastinal nodes in 157 patients with lung cancer were excised for staging of the disease through mediastinoscopy or thoracoscopy. Among them, 474 stations of mediastinal nodes in 151 patients were examined for metastasis both with imprint cytology and with hematoxylin-eosin histology independently. The final diagnostic decision was made by overall pathologic information, including cytology and histology. The diagnostic accuracies were compared between cytologic and histologic examinations.

Results

Cytologic examination identified 66 positive stations and 2 suspicious stations in 45 patients, whereas histologic examination identified 61 positive stations in 42 patients. The final pathologic diagnosis was 70 positive stations and 1 suspicious station in 45 patients. The sensitivity, accuracy, and negative predictive value of cytologic examination for node metastasis were 95.7%, 99.4%, and 99.3%, respectively, and those of histologic examination were 87.1%, 98.1%, and 97.7%, respectively. On a patient basis the sensitivity, accuracy, and negative predictive value of cytologic examination were 100%, 100%, and 100%, respectively, whereas those of histologic examination were 93.8%, 98.0%, and 97.2%, respectively. An additional 3 patients (2.0%) who had contralateral mediastinal node metastasis diagnosed only with cytology were identified with upstaged disease.

Conclusions

Imprint cytology for detecting metastasis of lung cancer in mediastinal nodes has high sensitivity and accuracy and is no less useful than histologic examination.     

Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer

OBJECTIVE: To determine the sensitivity, specificity, and accuracy of positron emission tomography with 2-fluorine-18-fluorodeoxyglucose (PET-FDG) in the preoperative staging (N and M staging) of patients with lung cancer. The authors wanted to compare the efficacy of PET scanning with currently used computed tomography (CT) scanning. MATERIALS AND METHODS: Results of whole-body PET-FDG imaging and CT scans were compared with histologic findings for the presence or absence of lymph node disease or metastatic sites. Sampling of mediastinal lymph nodes was performed using mediastinoscopy or thoracotomy. RESULTS: PET-FDG imaging was significantly more sensitive, specific, and accurate for detecting N disease than CT. PET changed N staging in 35% and M staging in 11% of patients. CT scans helped in accurate anatomic localization of 6/57 PET lymph node abnormalities. CONCLUSION: PET-FDG is a reliable method for preoperative staging of patients with lung cancer and would help to optimize management of these patients. Accurate lymph node staging of lung cancer may be ideally performed by simultaneous review of PET and CT scans.     

Surgical assessment and intraoperative management of mediastinal lymph nodes in non-small cell lung cancer

Mediastinal lymph node status has important prognostic and therapeutic implications for nonsmall cell lung cancer patients. Consequently, an accurate pathologic assessment of mediastinal lymph nodes for metastasis is essential. Despite the significance of nodal assessment, practice patterns among surgeons vary widely. Therefore we reviewed the literature to provide evidence-based recommendations regarding the ideal means and extent of preoperative and intraoperative pathologic mediastinal lymph node staging in non-small cell lung cancer patients. We found that the most sensitive and accurate intraoperative method is a complete mediastinal lymph node dissection. Pathologic evaluation of at least 10 mediastinal lymph node from at least three stations should be performed at the time of surgery.     

Endoscopic evaluation of the tracheobronchial tree and mediastinal lymph nodes

Assessment of the airways and surrounding structures, including the mediastinum and pulmonary parenchyma, has been greatly facilitated by advancements in bronchoscopic techniques, both rigid and flexible. Recent years have seen an explosion in technologies that have revolutionized the ability to visualize, biopsy, or otherwise assess regions of potential pathology within the upper aerodigestive tract and adjacent structures. This article concisely and comprehensively reviews the endoscopic evaluation of the tracheobronchial tree and mediastinum with a focus on emerging technologies and their role in treatment of thoracic disease.     

Helical computed tomographic scan in the evaluation of mediastinal gunshot wounds

BACKGROUND: The standard evaluation of mediastinal gunshot wounds usually requires angiography and either esophagoscopy or esophagography. In the present study, we have evaluated the role of helical computed tomographic (CT) scanning in reducing the need for angiographic and esophageal studies. METHODS: This was a prospective study of patients with mediastinal gunshot wounds who were hemodynamically stable and would otherwise require angiography and esophageal evaluation. All patients underwent CT scan of the chest with intravenous contrast to delineate the missile trajectory. If the missile tract was in close proximity to the aorta, great vessels, or esophagus, then traditional evaluation with angiographic or esophageal evaluation was pursued. RESULTS: A total of 24 patients met the inclusion criteria and underwent CT scan evaluation of their mediastinal gunshot wounds. One patient was taken for sternotomy to remove a missile embedded in the myocardium solely on the basis of the result of the CT scan. Because of proximity of the bullet tract, 12 patients required additional evaluation with eight angiograms and nine esophageal studies. One of these patients had a positive angiogram (bullet resting against the ascending aorta) and underwent sternotomy for missile removal; all other studies were negative. The remaining 11 patients were found to have well-defined missile tracts that approached neither the aorta nor the esophagus, and no additional evaluation was pursued. There were no missed mediastinal injuries in this group. Overall, 12 of 24 patients (50%) had a change in management (either received an operation or avoided additional radiographic or endoscopic evaluation) on the basis of the CT scan. CONCLUSION: The helical CT scan provides a rapid, readily available, noninvasive means to evaluate missile trajectories. This permits accurate assessment of potential mediastinal injury and reduces the need for routine angiographic and esophageal studies.     

Subpleural injection of tracer improves detection of mediastinal sentinel lymph nodes in non-small cell lung cancer.

BACKGROUND: The advantages and disadvantages of various tracer injection protocols for sentinel lymph node (SLN) mapping have been extensively discussed in relation to breast and gastric cancer. But no such discussion has taken place in relation to SLN mapping in non-small cell lung cancer. We therefore studied the effect of two tracer injection protocols on SLN mapping in patients with non-small cell lung cancer; of particular interest was the relationship between subpleural tracer injection and identification of mediastinal SLNs. METHODS: A quadrant injection group (n=49) received 1.6 ml of ferucarbotran by peritumoral quadrant injection after thoracotomy. In the subpleural injection group, the same amount of ferucarbotran was injected into the peritumoral quadrants plus the subpleural region (n=27). SLNs were then detected intraoperatively by measuring the magnetic force within lymph nodes using a hand-held magnetometer. After completing the SLN mapping, lobectomy and hilar and mediastinal lymph node dissection was performed. RESULTS: The incidence of mediastinal SLNs was significantly higher in the subpleural injection group (45.4%) than in the quadrant injection group (14.6%) (p=0.007). Moreover, nominal logistic regression analysis revealed subpleural injection to be a significant independent factor contributing to detection of mediastinal SLNs (p=0.024, odds ratio 5.26). In the quadrant injection group, mediastinal lymph node metastasis was detected in two patients thought to have nonmetastatic parenchymal SLNs. By contrast, there were no false-negative cases in the subpleural injection group. CONCLUSION: Subpleural tracer injection significantly improves detection of mediastinal SLNs in non-small cell lung cancer.