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.     

Computed tomography for staging of oesophageal cancer

BACKGROUND AND AIMS: Computed tomography (CT) is still widely used in the staging of patients with carcinoma of the oesophagus. The aim of the study was to evaluate the diagnostic accuracy of CT in a series of patients with carcinoma of the oesophagus or the cardia. Results were compared with findings at surgery or autopsy. MATERIAL AND METHODS: 47 consecutive patients of whom 30 underwent operation while 17 patients were not candidates for surgery due to advanced disease. RESULTS: Demonstration of tumour invasion on CT in 30 patients who underwent operation had an accuracy of 63%, a nosographic sensitivity of 10% and a specificity of 90%. Diagnosis of metastases to abdominal lymph nodes had an accuracy of 57%, and a nosographic sensitivity and specificity of respectively 37% and 90%. The assessment of tumour invasion and metastases to lymph nodes in patients not candidates for surgery was expectedly more accurate (100 and 67%, respectively, in nine autopsies). CONCLUSION: CT may provide valuable information in pretherapeutic staging of oesophageal cancer by identifying patients with advanced disease, who are not candidates for surgery. In patients without signs of dissemination on CT additional information may be obtained from endoscopic ultrasonography and laparoscopy.     

Role of positron emission tomography in mediastinal lymphatic staging of non-small cell lung cancer.

OBJECTIVE: Positron emission tomography (PET) is used increasingly in staging of non-small cell lung cancer (NSCLC) as a non-invasive tool. The role of the PET in mediastinal lymphatic staging of NSCLC is not clear. We aimed to demonstrate the efficacy of PET in determining mediastinal lymphatic metastasis by comparing the results of PET with mediastinoscopy. PATIENTS AND METHODS: We performed PET preoperatively in 170 patients with clinically operable NSCLC between 2004 and 2006. Stations defined as metastasis by PET (SUV(max) >2.5) were recorded. Mediastinoscopy was performed initially in all patients and a total of 687 stations which can be reached with mediastinoscope were sampled (mean 4.04). Forty-three patients with mediastinal metastasis were referred to the oncology clinic for chemotherapy while lung resection and complete mediastinal lymphatic dissection through thoracotomy was performed in the remaining 127 patients. Involvement of mediastinal lymph nodes was verified to compare the sensitivity and specificity of mediastinoscopy and the related PET results. RESULTS: Histopathologic classification of the tumors revealed 79 squamous carcinomas and 58 adenocarcinomas. False positivity rate of PET was 26% (95% CI: 14-38), false negativity was 25% (95% CI: 18-33), sensitivity was 74% (95% CI: 63-86), specificity was 73% (95% CI: 66-82) and accuracy was 74% in mediastinal staging. Negative predictive value of mediastinoscopy was 94% (95% CI: 89-98), positive predictive value 100%, sensitivity 84% (95% CI: 74-94), specificity 100% and accuracy was 95%. CONCLUSION: PET results do not provide acceptable accuracy rates. Mediastinoscopy still remains the gold standard for mediastinal staging of NSCLC, although it cannot reach to all the mediastinal stations.     

Integration of mediastinal staging techniques for lung cancer

Accurate mediastinal staging is important, and many imaging and invasive mediastinal staging tests are available. The data are confusing because patients with particular characteristics (ie, node size or location) are selected for different staging procedures. An approach is presented that integrates the various available tests and selects those tests with the highest ability to answer the question at hand. The goal is to maximize efficiency by enhancing staging accuracy while minimizing the number of tests each patient is subjected to.     

Computed tomography in lung cancer

Computer-assisted tomography produces a cross-sectional image of the body using x-ray absorption measurements. Density differences are much more apparent than on conventional radiographs, although spatial resolution is not so fine. Lung cancer can be evaluated accurately with regard to size, location, and whether regional or mediastinal lymph nodes are enlarged. Although enlarged granulomatous nodes generally tend to be dense, histologic specificity is not available.Computed tomography is recommended as a screening technique in lung cancer staging for patients whose routine radiographs are normal but whose primary lesions fulfill criteria for mediastinoscopy. If findings on computed tomography are normal, thoracotomy should then be performed; if enlarged nodes are detected, then a biopsy is needed to exclude operability. This strategy presumes that computed tomography has high sensitivity, although it remains to be proven by further experience whether the false-negative rate of computed tomography is an acceptable 10 to 15 percent. Computed tomography has been shown to be of considerable value in optimizing radiation therapy of lung cancer, and in diagnosing pleural complications of the cancer or its treatment.     

Advantages of positron emission tomography over computed tomography in mediastinal staging of non-small cell lung cancer

BACKGROUND: New treatment algorithms in early stage non-small cell lung cancer (NSCLC) involving preoperative chemotherapy require accurate clinical staging of the mediastinum. This study compares the accuracy of 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) scanning with that of computed tomography (CT) scanning in the clinical staging of non-small cell lung cancer. MATERIALS AND METHODS: A retrospective review was performed on 52 patients with NSCLC who were evaluated with both CT and PET scans. All patients had their mediastinal lymph nodes sampled by mediastinoscopy or at the time of thoracotomy for pulmonary resection. Each imaging study was evaluated separately and correlated with histopathologic results. RESULTS: For detecting mediastinal metastases the sensitivities of PET and CT scans were 67 and 50%, respectively; specificities were 91 and 65%, respectively; accuracies were 88 and 63%, respectively; positive predictive values were 50 and 16%, respectively; negative predictive values were 95 and 88%, respectively. PET scans were significantly better than CT scans at detecting mediastinal metastases (PET, 4/8; CT, 3/19) (P = 0.01). CONCLUSIONS: PET scanning is superior to CT scanning for clinical staging of the mediastinum in NSCLC. A more confident decision regarding stratification of patients into current treatment algorithms can be made when the decision is based on PET scanning rather than the current "gold standard" of CT scanning.     

Transcervical extended mediastinal lymphadenectomy--the new operative technique and early results in lung cancer staging.

OBJECTIVE: Mediastinal staging is one of the most important problems in thoracic surgery. Although the pathological examination is a generally accepted standard, none of the currently used techniques enables complete removal of all lymph node stations of the mediastinum. The aim of the study is to present a new technique of transcervical extended mediastinal lymphadenctomy (TEMLA) and to analyze its value in lung cancer staging. METHODS: In the prospective study of consecutive group of non-small cell lung cancer (NSCLC) patients, operated on between January and August 2004, we evaluated the usefulness of this original technique of bilateral mediastinal lymphadenectomy, assessing its accuracy and safety. The operations were performed through the transcervical approach, were videomediastinoscopy-assisted, with sternum elevation. Lymph node stations 1, 2R, 2L, 3a, 4R, 4L, 5, 6, 7 and 8 were removed. In patients without mediastinal metastases thoracotomy with pulmonary resection was performed and mediastinum searched for any missed lymph nodes. RESULTS: There were 83 patients operated on with the TEMLA technique. The mean number of nodes removed was 43 (range: 26-85). The sensitivity, specificity and accuracy of the presented method in detecting mediastinal node metastases were: 90, 100, and 96%, respectively, whereas the positive and negative predictive values were: 100 and 95%, respectively. CONCLUSIONS: The TEMLA technique is a safe and highly accurate method of mediastinal staging in NSCLC.     

Computed tomography of bladder: staging of bladder cancer using low density opacification technique.

In the course of computed tomographic (CT) evaluations involving 200 patients with suspected pelvic disease we have found that scan quality is often suboptimal. A preliminary report employing a low density bladder opacification method is presented whereby an indwelling catheter is inserted to control bladder volume and facilitate the instillation of low density iodinated contrast agent (0.6% Renografin-60). The patient remains supine throughout the twenty-five-minute procedure. Observations during the CT staging and follow-up of a controlled group of 8 patients undergoing immunotherapy and/or radiation therapy for bladder carcinoma indicate that this is a simple, safe, and effective staging procedure. We have obtained reliable clinical-radiologic-pathologic corrlation as a result of careful surgical staging and biopsy, followed by open surgery and full pathologic examination. It is hoped that this information will help initiate other similar studies to determine the diagnostic accuracy of this method and thus its use in pretherapeutic evaluation of the bladder lesion and its subsequent response to treatment.     

Computed tomographic staging of anterior mediastinal neoplasms.

Sixty patients with anterior mediastinal neoplasms undergoing computed tomography before surgical exploration were entered in a prospective study to assess the value of computed tomography in the preoperative staging of anterior mediastinal tumours. Correct prediction of location, size, and tissue density was obtained in all 60 cases. Correct identification of the nature of the tumours was achieved by computed tomography in 37 of the 54 previously undiagnosed cases. Particular attention was given to the evaluation of the relation of the tumour to adjacent mediastinal structures, to predict the feasibility of radical surgical procedures. Overall sensitivity, specificity, and accuracy in identifying resectability were 46%, 85%, and 64%, with positive and negative predictive indices of 78% and 58%. Capsulated or highly invasive lesions were clearly distinguished, and the presence or absence of infiltration of mediastinal vessels, pericardium, and chest wall was correctly recognised in most cases. It is suggested that the evaluation of anterior mediastinal neoplasms should include computed tomography because of its accuracy in predicting size, location, and tissue density of the neoplasm. Computed tomography may suggest, often with good reliability, the histological type of the tumour and its relation to contiguous mediastinal structures, thus contributing to the choice of the appropriate surgical approach or route for biopsy.     

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.     

Oncological issues in staging mediastinal lymph node metastasis for left lung cancer

ObjectiveWe aimed to discuss the underlying oncological issues in staging of mediastinal lymph node metastasis in patients with left lung cancer who underwent extended radical lymphadenectomy (ERL).MethodsThis multi-institutional retrospective study analyzed 116 patients with left non-small-cell lung cancer who underwent bilateral paratracheal lymph node dissection (ERL) via median sternotomy. The clinicopathological records of patients with mediastinal lymph node metastasis were examined for prognostic factors, including age, sex, histology, tumor size, cN number, preoperative data, metastatic stations (number and distribution), pT, and adjuvant chemotherapy.ResultsMediastinal lymph node metastases were found in 43 patients, and right paratracheal lymph node metastases (pN3) were found in 13 patients. The 5-year overall survival rate was 25.2% in patients with pN3 tumors (n = 13) and 23.1% in patients with pN2 tumors (n = 30). The prognosis did not differ between patients with pN3 and pN2. Univariate analyses showed that histology, cN, and adjuvant chemotherapy were significant prognostic factors in patients with mediastinal lymph node metastasis. In these 43 patients, cN and adjuvant chemotherapy were significant independent prognostic factors in multivariate analysis.ConclusionsThe prognostic factors for left lung cancer with mediastinal lymph node metastasis were cN status and adjuvant chemotherapy, and not pN status (pN2 or pN3). We hope that the study results, which suggest that there may be no difference in prognosis between pN2 and pN3, would broaden the discussion of oncological issues in the staging of mediastinal lymph node metastasis of left lung cancer.     

Evaluation of mediastinoscopy in mediastinal lymph node staging for non-small-cell lung cancer

Open in a separate window OBJECTIVESThe purpose of this study was to assess the quality of video-assisted cervical mediastinoscopy (VACM) in the staging of non-small-cell lung cancer (NSCLC) at the Antwerp University Hospital with a focus on test effectiveness indicators, morbidity and unforeseen pN2 results.METHODSAll consecutive VACM workups of cases of NSCLC performed between January 2010 and December 2015 were included to assess overall test quality and effectiveness. Quality assurance was performed in accordance with the recommendations of the European Society of Gastrointestinal Endoscopy and European Society of Thoracic Surgeons (ESTS) where appropriate.RESULTSA total of 168 video-assisted cervical mediastinoscopies were included. A total of 91.7% of the procedures were performed in accordance with the ESTS guideline. An unforeseen pN2 staging was identified in 10 anatomical lung resections (8.6%). Statistical analysis showed no significant association between VACM performed in accordance with the ESTS guideline and the presence of pN2 positive lymph nodes [χ² (1) = 0.61; P = 0.57] and no association between VACM performed in accordance with the ESTS guideline and overall futile thoracotomy [χ² (1) = 0.76; P = 0.50]. Calculations revealed a sensitivity of 81.8 [95% confidence interval (CI) 69.1–90.9], specificity of 100%, positive predictive value of 100%, negative predictive value of 91.9% (95% CI 86.6–95.2) and diagnostic accuracy of 94.1% (95% CI 89.33–97.11).CONCLUSIONSOverall, 91.7% of the VACM were performed in accordance with the ESTS guideline. This process resulted in a sensitivity of 81.8%, a negative predictive value of 91.9% and an unforeseen pN2 rate of 8.6%.     

Improved staging using intraoperative ultrasound for mediastinal lymphadenectomy in non-small lung cancer surgery

BackgroundExtent of lymph node involvement in patients with non-small cell lung cancer (NSCLC) is the cornerstone of staging and influences both multimodality treatment and final outcome. The aim of this study was to investigate accuracy and characteristics of intraoperative ultrasound guided systematic mediastinal nodal dissection in patients with resected NSCLC.MethodsFrom January 2008 to June 2013, 244 patients undergoing intraoperative surgical staging after radical surgery for NSCLC were included in prospective study. The patients were divided in two groups according to systematic mediastinal nodal dissection: 124 patients in intraoperative ultrasound nodal dissection guided group and 120 in standard nodal dissection group. The lymph nodes were mapped by their number and station and histopathologic evaluation was performed.ResultsOperating time was prolonged for 10 min in patients with ultrasound guided mediastinal nodal dissection, but number and stations of evaluated lymph nodes were significantly higher (p < 0.001) in the same group. Skip nodal metastases were found in 24% of patients without N1 nodal involvement. Twelve (10%) patients were upstaged using US guided mediastinal lymphadenectomy. In US guided group 5-year survival rate was 59% and in the group of standard systematic mediastinal lymphadenectomy 43% (p = 0.001) Standard staging system seemed to be improved in ultrasound guided mediastinal lymphadenectomy patients. Complication rate showed no difference between analyzed groups.ConclusionHigher number and location of analyzed mediastinal nodal stations in patients with resected NSCLC using ultrasound is suggested to be of great oncological significance. Our results indicate that intraoperative ultrasound may have important staging implications.     

Factors causing inaccurate staging of mediastinal nodal involvement in non-small cell lung cancer patients staged by positron emission tomography

Despite documented superiority of positron emission tomography over other investigative modalities in the preoperative staging of non-small cell lung cancer, a proportion of patients will have an inaccurate staging of their mediastinal nodes. The aim of this retrospective review is to analyse the clinicopathological factors responsible for inaccurate nodal staging by integrated PET-CT. A total of 100 consecutive patients with histologically proven non-small cell lung cancer underwent staging with PET-CT prior to lung resection. Thirty-three patients, inaccurately staged by PET-CT, were analysed. Univariate analysis identified the following as significant in causing inaccurate nodal staging: history of tuberculosis (P=0.039) and non-insulin dependant diabetes (P=0.014). In multivariate analysis, we have identified the following as independent factors in causing inaccurate staging of mediastinal lymph nodes: rheumatoid arthritis, non-insulin dependent diabetes, history of tuberculosis, presence of atypical adenomatous hyperplasia and pneumonia (P<0.05). The highest rate of inaccuracy in mediastinal nodal staging was in nodal station 4 (11%, P=0.01) followed by station 7 (10%, P=0.02) and station 9 (3.5%, P=0.01). Interpretation of PET-CT staging of the mediastinum in patients with a history of the above should be with caution, as the incidence of false upstaging and down staging in these subgroups is high. Vigilance of such factors may improve the accuracy of PET-CT in staging mediastinal lymph nodes. Histological confirmation should always be sought.     

The transcervical extended mediastinal lymphadenectomy versus cervical mediastinoscopy in non-small cell lung cancer staging.

OBJECTIVE: To compare the diagnostic yield of the transcervical extended mediastinal lymphadenectomy (TEMLA) and the cervical mediastinoscopy (CM) in detecting metastatic mediastinal lymph nodes in NSCLC patients. METHODS: Prospective, randomized, single-blind clinical study. RESULTS: There were 41 NSCLC patients enrolled in the study; 21 were randomized to the TEMLA group and 20 to the cervical mediastinoscopy group. The TEMLA revealed mediastinal metastases in 7 patients, and mediastinoscopy in 3. In the TEMLA group one patient out of the 14 with negative nodes was finally found unfit for surgery, and in the remaining 13 lung resections with mediastinal dissection were performed. In the mediastinoscopy group one patient out of the 17 with negative nodes was finally found unfit for surgery and another one refused surgery, so in 15 of them lung resections with mediastinal dissection were performed. In no patient in the TEMLA group did the pathological examination of the operative specimen reveal metastatic lymph nodes, whereas in the mediastinoscopy group metastatic nodes were found in 5 patients. The number of false negative results was significantly greater in the mediastinoscopy group (5 vs 0, p=0.019), and the difference was the reason for terminating the randomization before reaching the initially planned number of 100 patients. The sensitivity of mediastinoscopy was 37.5% and its negative predictive value was 66.7%, compared to 100% and 100% in the TEMLA group. The comparison of the time of the operation, blood loss, complications, postoperative pain and the use of analgetics has shown significant differences between groups only regarding the operative time and the pain intensity, being greater in the TEMLA group. CONCLUSIONS: 1. The sensitivity and the NPV of the TEMLA in detecting mediastinal metastases in NSCLC are significantly greater than those of cervical mediastinoscopy. 2. The invasiveness of TEMLA and mediastinoscopy does not significantly differ, except for the postoperative pain.     

Computed tomography for the evaluation of intrathoracic invasion by lung cancer

We conducted computed tomographic examinations of the chest in 171 patients with lung cancer whose disease was subsequently surgically staged; routine mediastinal exploration was undertaken in all patients undergoing thoracotomy (151), and in 20 patients only anterior mediastinotomy or mediastinoscopy was performed. We have considered three groups of patients: In Group I (including all 171 patients) mediastinal lymph nodes were evaluated for metastatic involvement; nodes were considered diseased when greater than 1 cm. Sensitivity, specificity, and accuracy were 95%, 83%, and 89%. Among these 171 patients, 34 (Group II) had a central tumor otherwise considered operable, which was shown on plain roentgenograms to be in contact with the mediastinum; infiltration of hilar and mediastinal vessels and of mediastinal tissues was investigated preoperatively with computed tomography and then ascertained at thoracotomy. Sensitivity, specificity, and accuracy were 68%, 72% and 70%. Twenty-seven patients (Group III) had a peripheral tumor abutting the pleural surface and suspected to invade the parietal pleura and chest wall; patients with evident bone infiltration were excluded. Sensitivity, specificity, and accuracy of computed tomography were 50%, 90%, and 65%.