Endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer diagnosis and staging

Pulmonary endoscopy - central to an interventional pulmonology program

INTRODUCTION

Pulmonary endoscopy occupies a central role in Interventional Pulmonology and is frequently the mainstay of diagnosis of respiratory disease, in particular lung malignancy. Older techniques such as rigid bronchoscopy maintain an important role in central airway obstruction. Renewed interest in the peripheral pulmonary nodule is driving major advances in technologies to increase the diagnostic accuracy and advance new potential endoscopic therapeutic options.

AREAS COVERED

This paper describes the role of pulmonary endoscopy, in particular ultrasound in the diagnosis and staging of lung malignancy. We will explore the recent expansion of ultrasound to include endoscopic ultrasound - bronchoscopy (EUS-B) and combined ultrasound (CUS) techniques. We will discuss in detail the advances in the workup of the peripheral pulmonary nodule.We performed a non-systematic, narrative review of the literature to summarize the evidence regarding the indications, diagnostic yield, and safety of current bronchoscopic sampling techniques.

EXPERT OPINION

EBUS/EUS-B has revolutionized the diagnosis and staging of thoracic malignancy resulting in more accurate assessment of the mediastinum compared to mediastinoscopy alone, thus reducing the rate of futile thoracotomies. Although major advances in the assessment of the peripheral pulmonary nodule have been made, the role of endoscopy in this area requires further clarification and investigation.

Endonasopharyngeal ultrasound and magnetic resonance imaging features of recurrent retropharyngeal nodes in nasopharyngeal carcinoma patients: A radiologic-histopathologic study

BACKGROUND

The imaging criteria of malignant retropharyngeal lymph node (RLN) in nasopharyngeal cancer (NPC) have yet to be fully elucidated. This study aimed to establish predictive models based on ultrasound (US) and magnetic resonance (MR) characteristics for identifying malignant RLN in NPC patients after radiotherapy.

METHODS

81 post-radiotherapy NPC patients with abnormal enlargement of RLN underwent endonasopharyngeal ultrasound-guided fine-needle aspirations (EPUS-FNA) to access the nature of RLN. The following features were assessed on US and MR: size, margin, vascular signal, echogenicity, enhancement signal and accompany with suspicious cervical nodes or not. A multivariate analysis was performed to screen out high-risk imaging features for recurrent RLN (RRLN), and models for the diagnosis of RRLN was constructed and tested with internal verification. We evaluated the clinical usefulness of the models through comparison of C-index and decision curve analysis.

RESULTS

High-risk features of RRLN were heterogeneous echo (p < 0.01), vascular signal (p < 0.01) on EPUS, heterogeneous enhancement (p < 0.01) and minimum axis diameter > 10 mm (p < 0.01) on MR. The models based on the US and MR features showed good discrimination (AUC of 0.76 in the US model, 0.74 in the MR model and 0.77 in the US + MR model) and good net benefit in the validation group.

CONCLUSION

Prediction models based on the US and MR features show good diagnostic performance for RRLN after radiotherapy in NPC patients. The combination of EPUS and MR may be constructed to provide prompt and reliable guidance to manage RLN.

Novel ProCore 25-gauge needle for endobronchial ultrasound-guided transbronchial needle aspiration reduces the puncture time and frequency, with comparable diagnostic rate for mediastinal and hilar lymphadenopathy

Background

The ProCore 25‐gauge needle is a novel specifically designed puncture needle for endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA), which may improve the puncture efficiency of the procedure while ensuring the diagnostic rate. The aim of the present study was to evaluate the diagnostic accuracy, mRNA yield, and complication rate of 25‐gauge needles compared to those of 22‐gauge needles in the evaluation of mediastinal and hilar lymphadenopathy.

Methods

A total of 39 patients undergoing EBUS‐TBNA at our institution were evaluated. All the procedures were performed by an experienced endoscopist formally trained in interventional pulmonology. Both the traditional 22‐gauge and ProCore 25‐gauge needles were used at each lymph node station. For all specimens obtained via EBUS‐TBNA, 50 μL was used to extract mRNA and detect the RNA concentration, whereas the other part was sent to the pathological evaluation. χ² test and t‐test were performed to determine the differences between the two types of the needles. A P‐value of <0.05 was considered significant.

Results

A total of 88 lymph nodes were punctured by the two needles separately. The diagnostic accuracy for each puncture between the two needles did not show any significant difference (P > 0.05). No serious procedure‐related complications were reported. In addition, the mRNA concentration did not differ between the two types of needles (P > 0.05).

Conclusion

The ProCore 25‐gauge needle gained a similar diagnostic yield with less puncture time and frequency compared with the 22‐gauge needle.

Diagnosing Lung Cancer: The Complexities of Obtaining a Tissue Diagnosis in the Era of Minimally Invasive and Personalised Medicine

The role of the respiratory physician in diagnosing lung cancer has increased in complexity over the last 20 years. Adenocarcinoma is now the prevailing histopathological sub-type of non-small cell lung cancer (NSCLC) resulting in more peripheral cancers. Conventional bronchoscopy is often not sufficient to obtain adequate tissue samples for diagnosis. Radiologically guided transthoracic biopsy is a sensitive alternative, but carries significant risks. These limitations have driven the development of complimentary bronchoscopic navigation techniques for peripheral tumour localisation and sampling. Furthermore, linear endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) is increasingly being chosen as the initial diagnostic procedure for those with central lesions and/or radiological evidence of node-positive disease. This technique can diagnose and stage patients in a single, minimally invasive procedure with a diagnostic yield equivalent to that of surgical mediastinoscopy. The success of molecular targeted therapies and immune checkpoint inhibitors in NSCLC has led to the increasing challenge of obtaining adequate specimens for accurate tumour subtyping through minimally invasive procedures. This review discusses the changing epidemiology and treatment landscape of lung cancer and explores the utility of current diagnostic options in obtaining a tissue diagnosis in this new era of precision medicine.

Endobronchial Ultrasound Elastography for Diagnosing Mediastinal and Hilar Lymph Nodes

BACKGROUND

Pathophysiological processes, such as malignancy, can lead to the formation of stiffer tissue in lung cancers. Endobronchial ultrasound (EBUS) elastography is a novel technique for measuring tissue stiffness during EBUS-guided transbronchial needle aspiration (EBUS-TBNA). The current study was conducted to investigate the diagnostic value of EBUS elastography for mediastinal and hilar lymph node metastasis in lung cancers.

METHODS

From January 2014 to January 2015, 40 patients suspected of lung cancer were enrolled, and a total of 68 lymph nodes were evaluated by EBUS-TBNA. EBUS-guided elastography of lymph nodes was performed prior to EBUS-TBNA. Standard EBUS characteristics were also described. Pathological determination of malignant or benign lymph nodes was used as the gold standard for this study. If EBUS-TBNA did not result in a formal pathological diagnosis of malignancy, patients were referred for a surgical procedure. Comparisons of elastography and standard EBUS characteristics were made between benign and malignant lymph nodes.

RESULTS

Elastography grading scores and strain ratios showed significant differences between benign and malignant lymph nodes (P = 0.000). The elastography strain ratio was more sensitive and specific for determining malignant lymph nodes than elastography grading score or standard EBUS criteria. The receiver operating characteristic curve for the elastography strain ratio showed an area under the curve of 0.933. The best cut-off point of the strain ratio for differentiating malignant from benign lymph nodes was 32.07. The elastography strain ratio had a sensitivity of 88.1%, the specificity of 80.8%, positive predictive value of 88.1%, and negative predictive value of 80.8% for distinguishing malignant from benign nodes. The overall accuracy of elastography strain ratio was 85.3%. The strain ratio of malignant and benign lymph nodes positively correlated with the elastography grading score (r = 0.561, P = 0.000).

CONCLUSIONS

EBUS elastography can be effectively used to predict mediastinal and hilar lymph node metastases in lung cancer. This noninvasive technique may thus complement standard EBUS and help guide EBUS-TBNA procedures.

Diagnostic value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions: Six cases reports and review of literature

BACKGROUND

Patients with isolated mediastinal or hilar lymphadenopathy, or peribronchial lesions, are common presentation to clinicians. Due to the difficulty in tissue sampling, the pathological diagnosis is not so easy. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established, highly effective, minimally invasive technique for sampling. The current study was conducted to investigate the value of EBUS-TBNA in patients of solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions.

METHODS

Six patients with different pathological results diagnosed via EBUS-TBNA were retrospectively analyzed in this study.

RESULTS

All 6 patients of solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions underwent conventional flexible bronchoscopy before EBUS-TBNA, but only EBUS-TBNA was helpful for the finally definite diagnosis. No complication was observed.

CONCLUSION

EBUS-TBNA is a safe and highly effective diagnostic procedure for both benign and malignant diseases, especially for patients with solitary mediastinal, hilar lymphadenectasis, or peribronchial lesions.

Convex probe EBUS for centrally located parenchymal lesions without a bronchus sign

BACKGROUND

Convex probe endobronchial ultrasound (CP-EBUS) has proven safe and accurate for identifying malignancy and granulomatous disease affecting the mediastinum and hilum. For the diagnosis of parenchymal lung lesions, conventional techniques such as transbronchial biopsy, brush and lavage are useful, particularly when an airway leads directly to the lesion. For centrally located intraparenchymal lesions, CP-EBUS has been shown to be efficacious.

OBJECTIVE

To expand on the existing literature in an effort to highlight the important diagnostic role of CP-EBUS in centrally located lesions, particularly those without a bronchus sign.

METHODS

In our cohort of 430 patients undergoing CP-EBUS between 03/2009-03/2012, we retrospectively identified 32 who underwent transbronchial needle aspiration (TBNA) of a centrally located parenchymal lung lesion. All lesions were completely surrounded by lung parenchyma and not visualized during white light bronchoscopy. Diagnostic yield was determined and compared to conventional bronchoscopic biopsy techniques, when performed.

RESULTS

The mean lesion size was 25.6 mm and 24/32 (75%) lesions were located in the lower lobes. A definitive diagnosis was obtained in 27/32 (84.4%) of parenchymal lesions without a bronchus sign biopsied using CP-EBUS. CP-EBUS provided the exclusive method of diagnosis in 15/32 (46.9%) patients in this cohort. Most lesions (26/32) were diagnosed as non-small cell carcinoma. There were no procedural complications.

CONCLUSION

CP-EBUS is useful for diagnosing parenchymal lung abnormalities without a bronchus sign, extending its scope beyond mediastinal and hilar lymph nodes. It is imperative that physicians performing EBUS maintain this tool as a complement to conventional bronchoscopic techniques.