Editorial Note on Echo Tip Pro Core

Kulashin Dandy^*
*Correspondence: Kulashin Dandy, Department of Medicine, Fujita Medical University, Tarakugakubo, Japan, Email:

Editorial

The use of real-time end bronchial ultrasound–guided transbronchial needle aspiration (EBUS-TBNA) for invasive mediastina staging of non–small cell lung cancer is well-established (NSCLC). For mediastinal staging, needlebased approaches are currently suggested as a first-line diagnostic modality. A thorough understanding of mediastinal anatomy is required for accurate EBUSTBNA systematic staging. Unless a higher station lymph node is positive for malignant cells by fast on-site cytologic examination, this evaluation begins at the N3 lymph nodes and progresses through the N2 and N1 lymph node stations. Any lymph node station having a visible lymph node or a lymph node greater than 5 mm in short axis can be sampled objectively to identify EBUSTBNA targets. Three passes per station are well-established approaches, as is the use of quick on-site cytologic examination with detection of diagnostic material (tumour or lymphocytes) up to five passes. It's possible that more than three passes are required to obtain enough tissue for molecular profiling. EBUS-TBNA has similar operational characteristics to mediastinoscopy. In the case of a negative EBUS-TBNA and a high posterior likelihood of N2 or N3 involvement, mediastinoscopy should be considered.

End bronchial ultrasound needle

Over the last decade, the use of real-time end bronchial ultrasound–guided transbronchial needle aspiration (EBUS-TBNA, also known as curvilinear probe EBUS-TBNA or linear EBUS-TBNA) has skyrocketed. EBUS-TBNA technology is presently in use in more than 85% of pulmonary and critical care programmes that participated in the survey. As EBUS-TBNA systems have become more common, so have the technology's applications.

Invasive sample of mediastina lymph nodes for non–small cell lung cancer (NSCLC) staging has been recommended by the American Thoracic Society, European Respiratory Society, European Society of Medical Oncology, and American College of Chest Physicians (ACCP). The ACCP Guidelines for Lung Cancer, third edition, recently suggested needle-based procedures as first-line approaches for invasive mediastina staging of NSCLC. The purpose of this study is to describe the methodology and procedures required to perform invasive mediastina staging for NSCLC using EBUS-TBNA.

Increasing the stage of NSCLC is always associated with a significant drop in survival. It is critical to correctly stage NSCLC in order to ensure that patients receive the best treatment possible. The combined sensitivity of integrated Positron Emission Tomography–Computed Tomography (PET-CT) for detecting NSCLC mediastina spread is only 62%. Positive PET-CT findings must also be confirmed to ensure that a false-positive result does not rule out potentially curative treatment. Despite these factors and guidelines for invasive mediastina staging, mediastinoscopy has been underutilised in the past. More patients may be able to undergo appropriate invasive mediastina staging now that EBUS-TBNA is widely available.

A thorough systematic evaluation of over 1,500 patients found no major EBUS-TBNA problems and only minor issues such as agitation, cough, and blood at the puncture site. Although problems such as mediastinitis, pericarditis, and mortality have been documented, prospective databases suggest that EBUS-TBNA complications occur at a rate of about 1%. Given EBUS-safety TBNA's record, improper pathologic staging may be the procedure's greatest risk. As a result, knowing the proper anatomic landmarks and lymph node stations is crucial. This necessitates rigorous adherence to the revisions stated in the 7th edition lymph node map produced by the International Association for the Study of Lung Cancer and later released by the Union for International Cancer Control.

The thoroughness of mediastina staging for needle-based procedures has been classified by Detterbeck and colleagues. Level A staging (full sampling) consists of sampling each visible lymph node in each station (1, 2R, 2L, 3, 4R, 4L, and 7) with at least three passes per node or rapid on-site cytologic assessment (ROSE). Malignant cells or lymphatic tissue must be reported if ROSE is used. No study has analysed the yield of complete mediastina staging aspirating all EBUS-TBNA–accessible stations to our knowledge (including 3p).

Due to the presence of big mediastinal vessels on either side, Station 3A cannot be accessible via EBUS-TBNA. At stations 2R, 2L, 4R, 4L, and 7, Level B staging (systematic assessment) necessitates sampling nodes in each station using at least three passes per node or ROSE. If a left upper lobe tumour is present, sampling stations 5 and 6 are required for both comprehensive (Level A) and systematic (Level B) staging. EBUS-TBNA has limited access to these stations. The only known exception is station 5 aspiration through the pulmonary artery, which has only been done in extreme cases. Station 5 has been aspirated inconsistently using endoscopic ultrasound-guided fine-needle aspiration. Others have questioned whether the lymph nodes sampled in these studies are lateral to the ligamentum arteriosum. Invasive staging of stations 5 and 6 may necessitate a surgical technique or transthoracic needle aspiration. Level C staging (selected evaluation) is defined as aspiration of at least one aberrant lymph node (measured in centimetres by CT or ultrasonography) or fewer than three passes with no ROSE. To date, research has concentrated on either systematic (Level B) or selective (Level C) staging. Further research may be needed to determine whether comprehensive (Level A) lymph node sampling in all accessible stations (including 1 and 3p) is superior than systematic (Level B) or selective (Level C) staging.

When compared to selected techniques, systematic surgical mediastinal staging has a higher accuracy, but the effect on overall survival is less obvious. There hasn't been a direct comparison of systematic and selective mediastinal staging with EBUS-TBNA. Given the sensitivity limitations of CT and PETCT, as well as the evidence from surgical techniques, systematic sampling of mediastinal lymph nodes through EBUS-TBNA may be preferable to selective sample. Selective staging of the mediastinum may be suitable in some cases. Further nodal sampling may be unnecessary if an enlarged N3 lymph node is aspirated with ROSE confirmation of malignant cells [1-5].

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