Ultrasound techniques in the evaluation of the mediastinum,part 2: mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques,clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography

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 (MLN) 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 should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [endobronchial ultrasound combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [endoscopic ultrasound fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all MLNs 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 1 deals with an introduction into ultrasound techniques, MLN anatomy and diagnostic reach of ultrasound techniques and part 2 with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography.     

TBNA with and without EBUS: a comparative efficacy study for the diagnosis and staging of lung cancer

Introduction

Conventional transbronchial needle aspiration (TBNA) has been around for over 30 years with sensitivities approaching 70-90%. Recent development of endobronchial ultrasound (EBUS) TBNA demonstrated even higher sensitivities among experts. However EBUS-TBNA is more costly and less available worldwide than conventional TBNA. A comparison study to determine the efficacy of TBNA with and without EBUS in the diagnosis and staging of lung cancer is described.

Methods

A total of 287 patients with mediastinal and hilar lymphadenopathy presenting for diagnosis and/or staging of lung cancer at enrolling institutions were included. Equal numbers of punctures were performed at the target lymph node stations using conventional TBNA techniques followed by EBUS-TBNA at the same sites. Patients and puncture sites that were biopsied by both methods and were positive for lung cancer were compared to establish efficacy of each technique on the same patients.

Results

In 253 patients at least one pair of specimens were obtained by conventional TBNA and EBUS-TBNA. In 83 of these patients malignancy was diagnosed. Among the 83 patients with a diagnosis of a malignancy there was no significant difference in the diagnostic yield of conventional TBNA versus EBUS-TBNA. When comparing diagnosis of malignancy for each lymph node sampled, there were a significantly greater number of positive (diagnostic for malignancy) lymph nodes sampled by EBUS-TBNA.

Conclusions

Recommendations for current practice depend on individual centers and bronchoscopist comfort level with TBNA (with or without EBUS). In our study, no significant difference was seen between the techniques for the diagnosis and staging of individual patients.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

Transgastric endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) in patients with esophageal narrowing using the ultrasonic bronchovideoscope

Endobronchial ultrasound‐guided fine needle aspiration (EBUS‐FNA) is emerging as a critical technology in the evaluation of mediastinal lesions and is increasingly regarded as complementary to endoscopic ultrasound (EUS) in this arena. This complementary role may extend into the abdomen in cases where esophageal strictures prevent the passage of the echoendoscope. The objective of the study was to characterize the uses of EBUS‐FNA in the evaluation of gastrointestinal lesions in patients with esophageal narrowing. The study design was a single‐center case series. The setting was in a tertiary referral center. Four patients underwent EBUS‐FNA to evaluate gastrointestinal lesions; esophageal strictures prevented EUS passage in three, the fourth patient did not tolerate transbronchial EBUS but had abdominal lesions within reach of the EBUS scope. EBUS was used to evaluate the liver, adrenal gland, a retroperitoneal mass, and a celiac axis lymph node. EBUS‐FNA has greater potential to evaluate abdominal lesions than has been previously recognized. The EBUS scope represents a safe and readily available technology to evaluate patients with esophageal strictures. Interventional endoscopists should be exposed to this modality.     

EUS GUIDED FNA FOR MEDIASTINAL TUMORS (LUNG CANCER AND LYMPH NODES)

Trans‐esophageal endoscopic ultrasound‐guided fine needle aspiration biopsy (EUS‐FNA) has proven to be a safe and minimally invasive tissue‐sampling method which can be used to obtain a cytological diagnosis from mediastinal lesions. The aims of EUS‐FNA in the mediastinum are either to diagnose a lesion of unknown origin, to stage mediastinal lymph nodes in lung cancer patients or to diagnose other diseases involving lymph nodes of the mediastinum. In patients with non‐small cell lung cancer (NSCLC), surgery may be regarded as futile in up to 45% of patients operated, apparently because the stage of the disease is more advanced than expected preoperatively. This, combined with a stage‐dependent multimodality treatment, underlines the importance of exact staging of the disease. Conventional imaging and tissue sampling methods all have variable sensitivities. Twenty‐two studies concerning EUS‐FNA and mediastinal staging of lung cancer have been published with a total number of 1245 patients. The reported sensitivity for mediastinal malignancy range from 0.61–1.00 (median 0.90), and with specificities of 0.71–1.00 (median 1.00). The majority of the studies are retrospective and present the results of EUS‐FNA performed in lung cancer patients selected by computer tomography (CT). Recent data suggests that EUS‐FNA in addition can diagnose advanced mediastinal disease in 22–42% of NSCLC patients with normal sized lymph nodes (< 1 cm) on chest CT. EUS‐FNA may also be used as a re‐staging procedure after induction chemotherapy and it seems that EUS‐FNA is more accurate for mediastinal staging of NSCLC compared to positron emission tomography (PET). However, further studies are necessary before final conclusions can be made. At present, mediastinoscopy is still considered complementary to EUS‐FNA because EUS‐FNA cannot visualize structures anterior to the air‐filled trachea and main bronchi. Endoscopic trans‐bronchial real‐time ultrasound guided biopsy (EBUS‐TBNA) performed via the trachea and main bronchi seems to be an obvious solution. Preliminary experience with a prototype EBUS‐TBNA bronchoscope (Olympus, XBF‐UC40P, Tokyo, Japan) in 214 patients has shown promising results. Hopefully the combination of EUS‐FNA and EBUS‐TBNA will be able to replace more invasive and risky staging methods and improve the N‐staging accuracy of the mediastinum and lung hilar regions in the near future.     

Endobronchial ultrasound

The efficacy and technical aspects of endobronchial ultrasound (EBUS) are reviewed because this technology promises to revolutionise bronchoscopy. EBUS extends the endoscopist's view beyond the mucosal surface of the large airways to peri-bronchial structures and peripheral lung lesions. Guided biopsies and real-time transbronchial needle aspirations (TBNA) have been shown to increase the diagnostic yield over conventional bronchoscopic techniques. The technology is available in two forms: radial EBUS probes and linear EBUS–TBNA bronchoscopes. Radial EBUS utilizes higher frequencies and the transducer is inserted via a standard flexible bronchoscope. The higher ultrasound frequencies improve image resolution to <1 mm. Radial EBUS is used to assess airway walls, guide TBNA (diagnostic yield: 72–86%) and diagnose peripheral lung lesions (diagnostic yield: 61–80%). Linear EBUS–TBNA transducers are built into dedicated bronchoscopes to produce sector view images and permit real-time TBNA. The pooled sensitivity of real-time EBUS–TBNA in lung cancer is 90% but the false negative rate is 20%. Therefore, EBUS–TBNA is a viable alternative to cervical mediastinoscopy in the diagnosis and staging of mediastinal lymphadenopathy. However, negative results need either further confirmatory testing or adequate clinical follow-up. Complications are rare with either EBUS modality and are usually related to the underlying biopsy procedure rather than the use of ultrasound. Procedure duration is short enough to be incorporated into an outpatient setting and can performed under moderate sedation. Clear training standards are emerging to facilitate credentialing as EBUS is rapidly evolving to become a part of standard diagnostic bronchoscopy.     

Endoscopic ultrasound‐guided fine‐needle aspiration when combined with positron emission tomography improves specificity and overall diagnostic accuracy in unexplained mediastinal lymphadenopathy and staging of non‐small‐cell lung cancer

Background: The aim of this study was to assess the incremental value of endoscopic ultrasound (EUS)‐guided fine‐needle aspiration (FNA) to positron emission tomography (PET) in the diagnosis of unexplained mediastinal lymphadenopathy and staging of non‐small‐cell lung cancer (NSCLC). Methods: Patients who had both EUS‐guided FNA and PET were retrospectively identified from an EUS database at a tertiary hospital. All EUS‐guided FNA were carried out by one endoscopist between August 2002 and April 2005, either for the diagnosis of unexplained mediastinal lymphadenopathy or for the staging of NSCLC. Results of PET and EUS were compared with histology. A true histological positive result was defined as histological involvement in either surgery (mediastinoscopy or resection) or EUS‐guided FNA. A true histological negative result was defined as negative involvement at surgery (mediastinoscopy or resection). Results: Forty‐nine patients who had both PET scanning and EUS‐guided FNA for diagnosis of unexplained mediastinal lymphadenopathy or staging of NSCLC were identified. Of these, 33 (73% males, n = 24, age range = 44–78 years, mean = 62 years) had surgical confirmation of mediastinal lymph node pathology. In these patients, PET alone showed sensitivity, 95%; specificity, 90%; positive predictive value, 87%; negative predictive value, 90% and accuracy, 88%; whereas the addition of EUS‐guided FNA increased the overall specificity and positive predictive value to 100%, with an overall accuracy of 97%. Conclusions: This study suggests that EUS‐guided FNA complements PET by improving the overall specificity and thereby the accuracy for diagnosis of unexplained mediastinal lymphadenopathy. It provides a minimally invasive technique to assess the mediastinum in patients with NSCLC and is particularly valuable in cases in which PET findings are equivocal.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

Advances in lung cancer diagnosis and staging: endobronchial ultrasound

Background:  Endobronchial ultrasound (EBUS) is an accurate and relatively less invasive procedure for the diagnosis of lung lesions and mediastinal lymph node staging for lung cancer. We aimed to evaluate the clinical utility and safety of this new EBUS service established in our hospital.
Methods:  Consecutive patients who underwent EBUS–transbronchial lung biopsy (EBUS–TBLB) for biopsy of peripheral pulmonary lesions or for transbronchial needle aspiration (TBNA) of mediastinal lymph node enlargement were included in this audit. Demographic and clinical data were obtained prospectively. Diagnostic yield from the results of EBUS was compared to other clinical information obtained.
Results:  Thirty-eight patients underwent EBUS over a 10-month period. The yield from EBUS–TBLB was 62%. The average size of the lung lesions biopsied was 3.5 cm and 62% were located in the upper lobes. Malignancy was diagnosed in 14 cases and a benign aetiology in four. The yield from EBUS–TBNA was 88% and the average size of the lymph nodes was 2.3 cm. The lymph nodes were all located in the subcarinal station except for two that were in the lower paratracheal station. Malignancy was diagnosed in 10 cases on TBNA and 4 cases had benign pathology. There was one complication seen (small pneumothorax).
Conclusion:  EBUS is safe and an effective method for both, diagnosis of peripheral pulmonary lesions and staging for lung cancer.     

Convex probe endobronchial ultrasound: applications beyond conventional indications

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is maturing and gaining acceptance by more and more clinicians for lymph node staging of lung cancer and diagnosis of mediastinal and hilar masses or lymph node enlargement by convex probe endobronchial ultrasound (CP-EBUS). The application of CP-EBUS, however, is not limited to conventional indications. Diagnostically, elastography is a new technology for the differentiation of benign and malignant lymph nodes before aspiration. CP-EBUS can also be used for pulmonary vascular diseases, such as pulmonary embolism (PE) and non-thrombotic endovascular lesions (NELs). Therapeutically, CP-EBUS can be used for cyst drainage and drug injections. CP-EBUS is not limited to observation and aspiration of mediastinal masses and lymph nodes, but is also suitable for exploration of other tissues external to the central airway, which necessitates unprecedented skills for the bronchoscopist.     

Endobronchial ultrasound-guided transbronchial needle aspiration for lung cancer staging: early experience in Brazil

Objective:

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive, safe and accurate method for collecting samples from mediastinal and hilar lymph nodes. This study focused on the initial results obtained with EBUS-TBNA for lung cancer and lymph node staging at three teaching hospitals in Brazil.

Methods:

This was a retrospective analysis of patients diagnosed with lung cancer and submitted to EBUS-TBNA for mediastinal lymph node staging. The EBUS-TBNA procedures, which involved the use of an EBUS scope, an ultrasound processor, and a compatible, disposable 22 G needle, were performed while the patients were under general anesthesia.

Results:

Between January of 2011 and January of 2014, 149 patients underwent EBUS-TBNA for lymph node staging. The mean age was 66 ± 12 years, and 58% were male. A total of 407 lymph nodes were sampled by EBUS-TBNA. The most common types of lung neoplasm were adenocarcinoma (in 67%) and squamous cell carcinoma (in 24%). For lung cancer staging, EBUS-TBNA was found to have a sensitivity of 96%, a specificity of 100%, and a negative predictive value of 85%.

Conclusions:

We found EBUS-TBNA to be a safe and accurate method for lymph node staging in lung cancer patients.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.     

经支气管镜气道内超声诊断的临床应用

传统气管镜和图像检查方法在确定肺癌纵隔淋巴结分期和外周小结节病变定性诊断上明显不足.往往需要纵隔镜及胸腔镜等有创方法来进一步确诊和评估分期.经支气管镜气道内超声检奁(endobronchial ultrasonograghy,EBUS)和超声下经支气管穿刺活检(endobronchial ultrasound transbronchial needle aspiration,EBUS-TBNA)是一种新的检查手段,利用超声探头通过支气管镜进入气道进行超声探测和获取病理的一种方法.该方法能大大拓展气管镜的视野,使其完全超越了气道壁的限制.采用EBUS和EBUS-TBNA对于纵隔肿瘤诊断和肺癌分期及判断肺癌患者有无纵隔转移有望代替纵隔镜和开胸探查,为肺癌和其他肺部病变提供新的检查方法.