Validation of transthoracic shear-wave ultrasound elastography in diagnosing pleural lesions

Purpose: This study used shear-wave ultrasound elastography to measure the stiffness of pleural lesions. The research hypothesis is that shear-wave elastography can add the elasticity information of the pleural lesions and help in the diagnosis of pleural diseases. Methods: This prospective observational study included one derivation cohort from May 2018 to Oct 2021 and one validation cohort from Nov 2021 to Aug 2022. The inclusion criterion was patients with radiographic evidence of pleural lesions or pleural effusion. We used the Toshiba Aplio 500 Platinum Ultrasound Machine to locate the pleural lesions and measure the elasticity of the pleural lesions. Diagnoses were made based on microbiological studies, pathology of pleural effusion or pleura, or following up the clinical course for at least 6 months. Results: A total of 210 patients with pleural lesions were included. The mean elasticity of the malignant pleural lesions was significantly higher than that of the benign pleural lesions (91.9 vs. 61.2 kPa, p< 0.001). Among the 103 patients in the derivation cohort, a receiver operating characteristic curve was constructed and the cut-off point to differentiate benign from malignant lesions was 60.2 kPa with an accuracy of 72.7% (sensitivity 81.3%, specificity 57.1%, and area under the ROC curve 0.69). Among the 107 patients in the validation cohort, the diagnostic performance was maintained with an accuracy of 73.8%. Conclusions: This study validated the use of shear-wave ultrasound elastography for assessing pleural malignancy. Additional studies using shear-wave elastography-guided pleural biopsy are warranted to further investigate the diagnostic yield.