Clinical utility of thoracic endosonography (EBUS/EUS-b) in mediastinal staging of patients with non-small cell lung cancer: comparison with integrated PET/CT-a real-life prospective study in Greece

What is new in mediastinal staging?

PURPOSE OF REVIEW

Appropriate staging is of utmost importance in nonsmall cell lung cancer (NSCLC), as the pathologic stage dictates both overall prognosis and appropriate therapeutic pathways. This article seeks to review the current recommendations for mediastinal staging of NSCLC and available modalities to achieve this. Landmark publications pertaining to recent advancements in NSCLC treatments are also highlighted and the role of specific bronchoscopic modalities for tissue acquisition are reviewed.

RECENT FINDINGS

Recent advancements in the treatment of NSCLC have made accurate mediastinal staging more important than ever. Guidelines and recommendations outlining patients that warrant invasive mediastinal staging are available and a systematic approach should be utilized when sampling is performed. Ensuring the adequacy of tissue for the growing number of molecular biomarkers that must be tested has been the focus of many recent studies.

SUMMARY

Appropriate mediastinal staging is crucial for the management of patients with NSCLC as is obtaining adequate tissue for diagnostic and therapeutic purposes. EBUS-TBNA is sufficient for the diagnosis of nonsmall cell and small cell lung carcinomas, but EBUS-guided intranodal forceps and cryobiopsy may provide more optimal specimen for patients with benign disease, such as sarcoidosis, or in cases of lymphoma. Further studies are necessary to better delineate the role of these techniques in the diagnosis and staging of mediastinal diseases before they become the primary diagnostic modalities.

PET-CT SUVmax and Endobronchial Ultrasound Features for Prediction of Malignancy: A Prospective Study

INTRODUCTION

Accurate and early staging of lung cancer has a critical impact on its prognosis. EBUS-TBNA is often the procedure of choice for mediastinal staging. Comprehension of the likelihood of malignancy of each lymph node (LN) can assist puncture decision-making during EBUS and offer insight of the procedure expected diagnostic yield.

METHODS

Prospective analysis of mediastinal LN of patients undergoing EBUS-TBNA from April 2021 to May 2022. The relationship between PET-CT SUVmax levels, EBUS features, and malignancy on LN was investigated. For statistical analysis, patients were assigned to 3 groups: suspected malignancy (diagnosis and/or staging), confirmed malignancy (staging) or suspected benign disease.

RESULTS

A total of 363 LN from 132 patients (71% male, mean 62 years old) were analyzed. Among those with suspected benign disease, no LN puncture resulted in a diagnosis of malignancy. PET-CT SUVmax and short axis size were independent factors for malignancy in LN of patients who underwent EBUS for suspected (p < .001 and p = .047, respectively) or confirmed malignancy (p < .001 and p < .001, respectively). All malignant LN presented SUVmax≥1.85 (≥2.85 for staging EBUS cases) and/or short axis size ≥4.28mm. Vascularized LN were more often malignant in either those with suspected (p = .087) or confirmed (p = .095) malignancy, although not statistically significant. LN that were simultaneously vascularized and lacked central hilar structure were also more commonly malignant (p = .013).

CONCLUSION

LN that has higher SUVmax and are larger should be prioritized for puncture, followed by those vascularized and lacking central hilar structure. In staging EBUS cases, a systematic sampling (N3-N2-N1) is required and must precede any malignancy yield rationale.

Transesophageal endoscopic ultrasound with bronchoscope-guided fine-needle aspiration for diagnostic and staging purposes: a narrative review

Background and Objective

Transesophageal endoscopic ultrasound with bronchoscope-guided fine-needle aspiration (EUS-B-FNA) is a feasible and well-tolerated modality that is increasingly used to diagnose intrathoracic lesions. This narrative review summarizes the current application of EUS-B-FNA for diagnosing lung cancer, thoracic sarcoidosis, and metastases from extrathoracic malignancies.

Methods

A comprehensive and systematic online literature search via Medline/PubMed for the period January 2005 to December 2022 was conducted for articles published using the keywords "EUS-B-FNA", "endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA)", "endoscopic ultrasound fine-needle aspiration (EUS-FNA)", "lung cancer", "staging", and "sarcoidosis".

Key Content and Findings

Recent data prove the efficacy and safety of EUS-B-FNA for providing complete lung cancer staging, when combined with EBUS-TBNA, and in the evaluation of para-esophageal lesions. EUS-B-FNA allows access to inferior mediastinal lymph nodes and para-esophageal masses that are not accessible by EBUS-TBNA. Additional advantages of using EUS-B-FNA include significantly lower doses of anesthetics and sedatives, a shorter procedural time, fewer incidents of oxygen desaturation due to a poor respiratory reserve, significantly less cough, and higher operator satisfaction. Moreover, this procedure can be performed sequentially in the same setting with EBUS-TBNA by one operator. Other benefits include a lower cost, a single setting, and scope use.

Conclusions

As EUS-B-FNA and EBUS-TBNA have complementary access to the mediastinum, the diagnostic yield of EUS-B-FNA combined with EBUS-TBNA is higher than that of endosonographic techniques alone in the diagnostic workup of intrathoracic lesions.

Imaging characteristics of nontuberculous mycobacterial pulmonary nodules

Introduction: Nontuberculous mycobacteriosis (NTM) of the lungs can develop nodules. In order to clarify some of the characteristics of lung NTM nodules, we examined volume doubling time (VDT) and maximum standardized uptake value (SUVmax) in positron emission tomography (PET) of pathologically diagnosed NTM nodules.Methods: From November 2012 to August 2018, clinical and radiological information were retrospectively investigated in 8 patients who were surgically resected and diagnosed as NTM. These eight patients were followed up until November 2020 and were confirmed to have no appearance of lung cancer or reappearance of lung NTM nodules. The VDT was calculated using the Schwartz formula.Results: The median maximum diameter of the nodule at the time of the first CT scan was 16.0 (range: 9.9-20.0) mm. The median maximum diameter of the nodule on CT performed before the surgical biopsy was 18.8 (range: 10.4-32.8) mm. The median doubling time calculated from these results was 203 (range: 20-568) days. Caseous granulomas and acid-fast bacilli were histologically confirmed in all 8 patients. Culture of excised nodules revealed Mycobacterium intracellulare in 5 patients and Mycobacterium avium in 3 patients. Six patients received PET, and median SUVmax was: 7.0 (range: 3.3-21.0). Median VDT was around 200 days. Some patients had irregular-shaped nodules.Conclusions: CT/PET-CT characteristics of lung nodules are not reliable in differentiating lung NTM nodules from malignant ones. To avoid unnecessary resection, it may be better to collect various information on imaging findings in the nodule itself and in opacities other than the nodule.