Utility and accuracy of endobronchial ultrasound as a diagnostic and staging tool for the evaluation of mediastinal adenopathy

Background

Endobronchial ultrasound (EBUS) is an emerging technology for mediastinal evaluation which is less invasive than cervical mediastinoscopy, the traditional gold standard. The purpose of our study is to evaluate the utility and accuracy of EBUS as a diagnostic and staging tool at our regional teaching institution.

Methods

We retrospectively reviewed the institutional thoracic surgery database for all patients undergoing EBUS between August, 2008 and March, 2011.

Results

190 patients underwent EBUS. 87 (46 %) patients underwent EBUS for diagnosis only; 73 (38 %) for staging only; and 30 (16 %) for both diagnosis and staging. Diagnoses obtained by diagnostic EBUS included non-small cell lung cancer—n = 36 (31 %); other cancer—n = 22 (19 %); sarcoid/granulomatous—n = 8 (7 %); benign lymphoid tissue—n = 50 (43 %); and was nondiagnostic in one case (1 %). For staging EBUS 53 (51 %) patients had benign lymph node tissue. 103 patients had a benign result at the time of EBUS. Fifty-six (54 %) of these patients underwent subsequent mediastinal lymph node dissection or mediastinoscopy for tissue confirmation with the remainder undergoing follow up surveillance chest CT scans. Two patients had a false negative EBUS. Both false negative studies sampled levels 4L, 4R, and 7. The overall false negative rate was 2 % for all benign results, and 4 % for those benign results confirmed with lymph node dissection or mediastinoscopy. The sensitivity and specificity of diagnostic EBUS was 97 and 100 %. The sensitivity and specificity for staging EBUS was 98 and 100 %. In those patients (n = 103) undergoing a staging EBUS, a mean of 2.6 nodal stations were sampled, with 59 % (n = 61) of these patients having three lymph node stations sampled and 33 % (n = 30) had two lymph node stations sampled.

Conclusion

We found that EBUS is a highly accurate and minimally invasive manner in which to both diagnose mediastinal masses and stage the mediastinum.