PURPOSE:Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has been proposed as a safe, less-invasive alternative to surgical mediastinoscopy for mediastinal staging. We evaluated the negative predictive value (NPV) of EBUS-TBNA compared to mediastinoscopy for ruling out metastatic N2 disease in patients with lung cancer.
METHODS:Retrospective review of cases with a suspected or confirmed diagnosis of lung cancer undergoing mediastinoscopy following a negative EBUS-TBNA at our institution between June 2006 and February 2008.
RESULTS:494 patients underwent EBUS-TBNA. 35 patients with a suspected or confirmed diagnosis of lung cancer had a negative EBUS-TBNA and underwent subsequent mediastinoscopy. Mediastinoscopy was performed for findings suspicious of N2 disease based on non-invasive imaging (CT or CT-PET). Mediastinoscopy found metastatic nodes in 12 of 35 patients (34%). The patient-specific NPV of EBUS-TBNA in this scenario was 66%. On average, mediastinoscopy sampled more lymph node stations per patient than EBUS-TBNA (1.5 vs. 2.2). EBUS-TBNA and mediastinoscopy sampled the same lymph node station in 44 occasions. Average lymph node size for these 44 stations was 12.7 mm (range 5 to 30 mm). PET evaluated 42/44 lymph node stations (95%) and was positive in 24 (57%). Mediastinoscopy found lymph node metastasis in nine cases, for a nodal-specific NPV of EBUS-TBNA of 80%. Station 4R was sampled 21 times (48%), followed by station 7 in 17 occasions (39%). The NPV at station 4R was 71%, while in station 7 it was 88%.
CONCLUSION:EBUS-TBNA can effectively sample mediastinal lymph node stations in patients with lung cancer. However, in this early experience, 34% of patients with high clinical suspicion of nodal disease had N2 mediastinal nodal metastases confirmed by mediastinoscopy despite negative EBUS-TBNA.
CLINICAL IMPLICATIONS:When EBUS-TBNA is negative in patients with lung cancer and the clinical suspicion of mediastinal disease is high, mediastinoscopy should be performed.
DISCLOSURE:Sebastian Defranchi, No Financial Disclosure Information; No Product/Research Disclosure Information