Abstract
BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) diagnoses and stages mediastinal lymph node pathology. This retrospective study determined the relationship between EBUS-TBNA utility and non-small cell lung cancer (NSCLC) stage, lymph node size, and positron emission tomography (PET) standard uptake values (SUV), and the utility of neck ultrasound in bulky mediastinal disease. METHODS: Data of 284 consecutive patients who had undergone EBUS-TBNA was collected. Two hundred patients had suspected NSCLC, with 148 confirmed NSCLC cases. The diagnostic utility of EBUS-TBNA was determined according to NSCLC stage, EBUS lymph node size, PET SUV, use in distal metastases, and mutation testing. The utility of neck ultrasound for N3 disease was calculated in patients with bulky mediastinal disease. RESULTS: EBUS-TBNA was well tolerated with 97% sensitivity in distant metastatic disease, avoiding the need for distal metastases biopsy in 81% of cases. It had equivalent diagnostic accuracy in all NSCLC stages and in lymph nodes <10 mm, <20 mm or >20 mm (sensitivity >92% in all cases), with no mutation testing failures. EBUS-TBNA had 33% sensitivity in PET indolent (SUV < 4) nodes and 79% sensitivity in PET active nodes (SUV > 4). EBUS-TBNA diagnosed 12 cases of lymphoma without flow cytometry. CONCLUSIONS: The use of EBUS-TBNA meant that distant metastatic biopsy was avoided in 81% of cases, performing well irrespective of cancer stage, node size, and facilitating mutation testing. Neck ultrasound failed to detect N3 disease in patients with bulky mediastinal disease. EBUS-TBNA had a sensitivity of 33% for metastases in PET negative nodes, highlighting PET limitations.