Linear and radial endobronchial ultrasound in diagnosis and staging of lung cancer

Abstract

Endobronchial ultrasound (EBUS) in recent years has become a routine diagnostic procedure in bronchology. Linear EBUS shows high diagnostic yield in evaluation of mediastinal lymph nodes. It is mainly used for nodal evaluation in lung cancer, but has also proven to be efficient in diagnostic evaluation of mediastinal masses. This technique has been shown to be complementary to mediastinoscopy. In combination with PET and rapid on site cytology (ROSE), the diagnostic yield of EBUS is significantly higher. Radial EBUS is used for diagnosis of peripheral lung lesions. This technique facilitates evaluation of bronchial wall in central lung cancer lesions, enabling differentiation between early and invasive lung cancer. The diagnostic yield of radial EBUS in the diagnostics of peripheral lung lesions is high, reducing the number of diagnostic thoracotomies. The application of miniature radial EBUS probes, together with guiding sheaths and other guiding accessories, allow the access to smaller and more peripheral lung lesions. In addition, EBUS bronchoscopy can be utilized for the placement of brachytherapy catheters, or evaluation of the distal bronchi in order to chose between different therapeutic bronchoscopic techniques for desobstruction. An experienced bronchoscopist, availability of ROSE and additional guiding devices might be necessary to accomplish the best possible results of EBUS bronchoscopy.

Keywords::

• bronchoscopy
• endobronchial ultrasound
• interventional pulmonology
• lung cancer
• mediastinum

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• • Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is completely complementary to mediastinoscopy in evaluating the mediastinal lymph nodes (MLN). It is effective in evaluating the MLNs after the neoadjuvant (chemo-radio) therapy, and previous mediastinoscopy.

• • EBUS-TBNA shows a high diagnostic value in the assessment of the lymph nodes less than 1 cm in diameter, even if the PET-computed tomography is negative.

• • EBUS-TBNA is successfully used for the diagnosis of MLN malignancy, mediastinal tumors, sarcoidosis or lymphoma.

• • Radial EBUS shows a high diagnostic value in evaluating the peripheral lung lesions, even smaller than 2 cm.

• • The combination of EBUS with other navigational techniques further increases the diagnostic yield.

• • The role of the radial EBUS in therapeutic bronchoscopy might be significant.