Abstract
Objective: EBUS elastography (E-ELT) is a new technique for describing the stiffness of tissue during EBUS-TBNA. This study was to evaluate the utility of E-ELT type classification for thoracic lymph nodes (LNs).
Methods: Seventy-five LNs were evaluated. E-ELT patterns were classified as follows: Type 1, predominantly non-blue; Type 2, part blue, part non-blue; Type 3, predominantly blue. The E-ELT patterns were compared with the pathologic results.
Results: The LNs that were classified as Type 1 on E-ELT were benign in 24/24 (100%); for Type 2 LNs, 6/14 (46.9%) were benign and 8/14 (57.1%) were malignant; Type 3 LNs were benign in 2/37 (5.4%) and malignant in 35/37 (94.6%). In classifying Type 1 as “benign” and Type 3 as “malignant,” the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy rate were 100%, 92.3%, 94.6%, 100% and 96.7%, respectively. The median values of FDG-PET SUVmax were 2.49 for E-ELT Type 1, 4.95 for Type 2, and 8.50 for Type 3. The computed Spearman rank coefficient (r) was 0.54 (P < 0.0001). The accuracy of conventional EBUS features in predicting malignant nodal metastasis were 70.0% (35/50) for size, 50.0% (8/16) for shape, 53.3% (24/45) for margin, 66.0% (37/57) for echogenicity and 67.6% (23/34) for vascular pattern.
Conclusions: EBUS elastography type classification is a useful tool with very high sensitivity, specificity and accuracy for differential diagnosis of mediastinal and hilar LNs. Aside from providing complementary information to conventional EBUS imaging, it may potentially increase the diagnostic yield of EBUS-TBNA and reduce the number of unnecessary biopsies.
- Copyright ©ERS 2015
