Diagnostic Value of Elastography and Endobronchial Ultrasound in the Study of Hilar and Mediastinal Lymph Nodes.

BACKGROUND: The aim of this study was to explore elastography features and its ability to distinguish between benign and malignant lymph nodes by comparing the results with an anatomopathologic examination used as gold standard.

METHODS: Patients were randomized in 2 groups [endobronchial ultrasound (EBUS) and EBUS-elastography]. Echographic characteristics of the lymph nodes were collected in both categories. In the EBUS-elastography group, elastographic data were also determined.

RESULTS: A total of 100 lymph nodes were evaluated. Group 1 (EBUS) consisted of 57 lymph nodes. Group 2 (EBUS-elastography) included 43 lymph nodes. In group 2, lymph nodes with predominantly blue pattern were associated with a pathologic determination of malignancy, and the probability of presenting malignant infiltration with this color pattern was 86.7% (P=0.00004). Malignant lymph nodes presented less color dispersion (48.8 vs. 94.8, P=0.00013), higher ratio of blue pixels (66% vs. 32.5%, P=0.016), and higher strain ratio (7.1 vs. 2.48, P=0.005). The cut-off points to distinguish between benign and malignant lymph nodes were 4 for strain ratio, 61 for frequency histograms, and 52 for blue pixel ratio. The area under the curve of the ROC curves were 0.75, 0.83, and 0.87, respectively. Group 2 presented a lower number of nondiagnostic samples (2.3% vs. 21%, P=0.001) and a higher rate of malignant results (42% vs. 16%, P=0.005).

CONCLUSION: EBUS-elastography is feasible during EBUS and may be helpful in predicting malignant lymph node infiltration. It could improve anatomopathologic sample collection and increase diagnostic efficiency.