Ultrasound techniques in the evaluation of the mediastinum,part I: endoscopic ultrasound (EUS), endobronchial ultrasound (EBUS) and transcutaneous mediastinal ultrasound (TMUS), introduction into ultrasound techniques

Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography (EUS and EBUS) should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [EBUS combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [EUS fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all mediastinal lymph nodes can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review, in two integrative parts, is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part I is dealing with an introduction into ultrasound techniques, mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques and part II with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography.     

Positron emission tomography/computed tomography and endobronchial ultrasound-guided transbronchial needle aspiration to evaluate the status of N2 in preoperative non-small cell lung cancer: a diagnostic test

BackgroundAs a minimally invasive method, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was more accurate than non-invasive methods such as positron emission tomography (PET) and computed tomography (CT) to evaluate the lymph nodes in preoperative non-small cell lung cancer (NSCLC). PET/CT has more anatomical advantages than PET scanning and is more accurate in lung cancer staging. However, no relevant studies have comparatively evaluated PET/CT and EBUS-TBNA for NSCLC patients.MethodsA total of 112 patients were included in this retrospective analysis. The golden diagnosis of N2 status was postoperative pathological results. In EBUS-TBNA puncture specimens, if clear malignant tumor cells could be seen, the results were taken as positive. In PET/CT image analysis, the CT values, short diameter, and maximum standardized uptake value (SUVmax) of each lymph node were recorded to evaluate N2 status. The results of PET/CT and EBUS-TBNA were compared with the final pathological results, and respective sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. - Then, the patients were divided into adenocarcinoma group and squamous cell carcinoma group -and the results were calculated and compared with the above method.ResultsThe results showed that EBUS-TBNA had a higher diagnostic value for mediastinal lymph nodes than PET/CT, and the difference was statistically significant (P<0.001). In NSCLC patients, the results showed that the sensitivity (P=0.013), specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.954 and 0.636, respectively). In adenocarcinoma cases, specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.957 and 0.596, respectively).In cases with squamous cell carcinoma, specificity (P=0.003), PPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than PET/CT (AUC =0.952 and 0.657, respectively).ConclusionsFor preoperative diagnosis of mediastinal lymph node metastases in NSCLC, EBUS-TBNA is more accurate than PET/CT. For those patients with suspected mediastinal lymph node metastasis, EBUS-TBNA should be preferred method to evaluate the status of mediastinal lymph nodes.     

Mediastinal staging of non-small-cell lung cancer among Australasian thoracic physicians: clinical practice and constraints on minimally invasive techniques

Background/Aim: We determined current practice among Australasian thoracic physicians in the mediastinal staging of non‐small‐cell lung cancer (NSCLC). We focused on the availability of endobronchial ultrasound‐transbronchial needle aspiration (EBUS‐TBNA) and constraints to its use, as there has been no systematic analysis regarding the availability and uptake of this new technology among thoracic physicians. Methods: Physician members of the Thoracic Society of Australia and New Zealand were emailed a survey seeking their current approach to three scenarios requiring mediastinal staging of NSCLC. Respondents were also asked for their preferred investigation for each scenario if any current constraints were removed. Relevant demographic information was sought. Results: We received 164 responses from 512 Australasian physicians (34%). Without constraints, EBUS‐TBNA was the preferred investigation for all three clinical scenarios, but only 33% of respondents had access to EBUS‐TBNA. Constraints included lack of availability and lack of expertise. Reduced EBUS‐TBNA access was associated with a number of clinician factors. Conclusions: Australasian thoracic physicians prefer EBUS‐TBNA for the mediastinal staging of NSCLC, but access to EBUS‐TBNA services is limited. We recommend targeted measures to improve access to EBUS‐TBNA use and optimise mediastinal staging of NSCLC.     

Endobronchial ultrasound-guided transbronchial needle aspiration of lymph nodes in the radiologically and positron emission tomography-normal mediastinum in patients with lung cancer

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can reliably sample enlarged mediastinal lymph nodes in patients with non-small cell lung cancer (NSCLC), and in practice is mostly used to sample nodes visible on CT or positron emission tomography (PET). Few data are available on the use of endoscopic procedures to stage the mediastinum in clinical stage 1 lung cancer. The aim of the present study was to determine the results of EBUS-TBNA in sampling mediastinal lymph nodes in patients with lung cancer and a radiographically normal mediastinum and no PET activity. From January 2004 to May 2007, patients highly suspicious for NSCLC with CT scans showing no enlarged lymph nodes (no node > 1 cm) and a negative PET finding of the mediastinum underwent EBUS-TBNA. Identifiable lymph nodes at locations 2r, 2L, 4r, 4L, 7, 10r, 10L, 11r, and 11L were aspirated. All patients underwent subsequent surgical staging. Diagnoses based on aspiration results were compared with those based on surgical results. One hundred patients (mean age, 52.4 years; 59 men) were included. After surgery, 97 patients (mean age, 52.9 years; 57 men) had NSCLC confirmed and were included in the analysis. In this group, 156 lymph nodes ranging 5 to 10 mm in size were detected and sampled. Malignancy was detected in nine patients but missed in one patient. Mean diameter of the punctured lymph nodes was 7.9 mm. The sensitivity of EBUS-TBNA for detecting malignancy was 89%, specificity was 100%, and the negative predictive value was 98.9%. No complications occurred. In conclusion, EBUS-TBNA can be used to accurately sample and stage patients with clinical stage 1 lung cancer and no evidence of mediastinal involvement on CT and PET. Potentially operable patients with no signs of mediastinal involvement may benefit from presurgical staging with EBUS-TBNA.     

Incidence and Risk Factors for Infectious Complications of EBUS-TBNA: Prospective Multicenter Study

The aim of our study was to describe the incidence of infectious complications of endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) and to analyze the potential risk factors in a prospective cohort of patients.MethodsWe conducted a prospective multicenter study, with all consecutive patients referred for an EBUS-TBNA with patients at risk of developing an infectious complication (considering > 10 nodal samplings, known immunosuppression, bronchial colonization and cavitated or necrotic lesions) and a second group without any risk factor.ResultsThree hundred seventy patients were included: 245 with risk factors and 125 without risk factors (as the control group). Overall, 15 patients (4.05%) presented an acute infectious complication: fourteen in cases (5.7%) and 1 in controls (0.8%). Of these, 4 patients presented pneumonia, 1 mediastinitis, 4 obstructive pneumonitis and 6 mild complications (respiratory tract infection that resolved with antibiotic). Also 7 (1.9%) patients had self-limited fever. One-month follow-up showed 1 mediastinitis at sixteenth day post-EBUS, which required surgical treatment, and 3 pneumonias and 3 respiratory tract infections at nineteenth day (1.9%). All patients had a good evolution and there were no deaths related with infectious complication. We observed an increased risk of complication in patients with risk factors and in patients with necrosis (p = 0.018).ConclusionsThe incidence of infectious complications in a subgroup of patients with risk factors was higher than in patients without risk factors. Nevertheless, it remains low, and no fatal complication occurred, which reinforces the idea that EBUS-TBNA is a safe technique for the assessment of the mediastinum. Necrotic lesions are a risk factor of post-EBUS infection, and their puncture should be avoided.