Effectiveness of the Benign and Malignant Diagnosis of Mediastinal and Hilar Lymph Nodes by Endobronchial Ultrasound Elastography

Abstract

Background and Objectives: Endobronchial ultrasound elastography is a new technique for describing the stiffness of tissue during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The aims of this study were to investigate the diagnostic value of Endobronchial ultrasound (EBUS) elastography for distinguishing the difference between benign and malignant lymph nodes among mediastinal and hilar lymph nodes.Materials and Methods: From June 2015 to August 2015, 47 patients confirmed of mediastinal and hilar lymph node enlargement through examination of Computed tomography (CT) were enrolled, and a total of 78 lymph nodes were evaluated by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). EBUS-guided elastography of lymph nodes was performed prior to EBUS-TBNA. A convex probe EBUS was used with a new EBUS processor to assess elastographic patterns that were classified based on color distribution as follows: Type 1, predominantly non-blue (green, yellow and red); Type 2, part blue, part non-blue (green, yellow and red); Type 3, predominantly blue. Pathological determination of malignant or benign lymph nodes was used as the gold standard for this study. The elastographic patterns were compared with the final pathologic results from EBUS-TBNA.Results: On pathological evaluation of the lymph nodes, 45 were benign and 33 were malignant. The lymph nodes that were classified as Type 1 on endobronchial ultrasound elastography were benign in 26/27 (96.3%) and malignant in 1/27 (3.7%); for Type 2 lymph nodes, 15/20 (75.0%) were benign and 5/20 (25.0%) were malignant; Type 3 lymph nodes were benign in 4/31 (12.9%) and malignant in 27/31 (87.1%). In classifying Type 1 as 'benign' and Type 3 as 'malignant,' the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy rates were 96.43%, 86.67%, 87.10%, 96.30%, 91.38%, respectively.Conclusion: EBUS elastography of mediastinal and hilar lymph nodes is a noninvasive technique that can be performed reliably and may be helpful in the prediction of benign and malignant lymph nodes among mediastinal and hilar lymph node during EBUS-TBNA.

Optimal Endobronchial Ultrasound Strain Elastography Assessment Strategy: An Explorative Study

“…Three studies used a scoring system like the color VAS scoring system, with comparable results [14, 18, 22]. He et al [14] reported best accuracy if the visualized color was over 50% blue, then indicative of malignancy with an accuracy of 73.7%.…”

“…He et al [14] reported best accuracy if the visualized color was over 50% blue, then indicative of malignancy with an accuracy of 73.7%. Huang et al [22] and Izumo et al [18] introduced an additional cut-off; only predominantly blue lesions were indicative of malignancy, while predominantly non-blue lesions were indicative of benign lymph nodes. By leaving out an intermediary group (part blue, part non-blue) they were able to report an overall accuracy in these categories of 91.4 and 96.7%, respectively.…”

“…For visual scoring of the strain, two VAS scoring methods based upon earlier reports were used [14, 17, 22]. The first VAS system requires the operator to classify the image into one of five groups based on the major color component.…”

“…This is done by converting calculated relative strain into a color gradient and superimposing it on the B-mode image. This strain color image is then used for scoring the lymph node region of interest upon its major color component [14, 17, 18, 22] or pattern-color combination [12]. Another frequently reported method is the semiquantitative strain ratio measurement [17, 19, 23].…”

Tumor heterogenicity: multiple needle biopsies from different lesion sites—key to successful targeted therapy and immunotherapy

“…In any case cell blocks are essential when we are using biopsy techniques with needles (16). Elastography can also nowadays assist in the evaluation of a lesion/lymphadenopathy and with or without a previously positron emission tomography performed we can have the valuable information were to inject our needle and whether the investigated lesion/lymphadenopathy is benign or malignant or unspecified (19). Choosing needles were possible can definitely provide us tumor heterogenicity since ultrasound techniques provide us with visualisation of the needle while puncturing and therefore we can repeat the sample movement as many times as possible and from different parts of a lesion.…”