Ultrasound-guided percutaneous needle biopsy for small pleural lesions: Diagnostic yield and impact of CT and ultrasound characteristics

BACKGROUND. Ultrasound (US)-guided percutaneous pleural needle biopsy (PCPNB) is widely used to evaluate pleural lesions, although its diagnostic accuracy is variable. OBJECTIVE. The purpose of this study is to assess the diagnostic yield of US-guided PCPNB for small (≤ 2 cm) pleural lesions and the impact of CT and US morphologic and technical factors. METHODS. A total of 103 patients (73 men and 30 women; mean [± SD] age, 68.0 ± 13.3 years) who underwent US-guided PCPNB of a small pleural lesion performed by a single experienced operator from July 2013 to December 2019 were retrospectively analyzed. Final diagnosis was established via histopathologic results, including findings from repeat US-guided and CT-guided biopsies as well as imaging and clinical follow-up. Pleural morphology and thickness were assessed on CT and US, and needle pathway length throughout the pleura was measured on US. Accuracy, sensitivity, specificity, PPV, and NPV were calculated. The association of diagnostic yield with imaging and technical factors was evaluated. ROC curve analysis was used to determine the optimal CT pleural thickness cutoff value. Multivariable logistic regression was performed to identify independent predictors of diagnostic yield. RESULTS. The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of US-guided PCPNB were 85.4%, 84.8%, 100.0%, 100.0%, and 21.1%, respectively. Diagnostic, compared with nondiagnostic, procedures more commonly (p ≤ .002) revealed nodular morphology on CT (96.4% vs 3.6%) and US (97.3% vs 2.7%,), greater pleural thickness on CT (7.5 vs 3.2 mm) and US (7.4 vs 3.0 mm), and a greater needle pathway length (11.0 vs 6.1 mm). The optimal cutoff value for pleural thickness on CT was 4.5 mm. Diagnostic yield was 96.4% for nodular lesions, 95.0% for diffuse lesions that had a thickness of 4.5 mm or greater on CT, 55.6% for diffuse lesions that had a thickness less than 4.5 mm on CT, and 100% for diffuse lesions on CT that had nodular morphology on US. Nodular morphology on US (p = .002) and needle pathway length (p = .04) were independent predictors of diagnostic yield. CONCLUSION. US-guided PCPNB has excellent diagnostic accuracy for small pleural lesions; imaging characteristics influence this accuracy. CLINICAL IMPACT. US-guided PCPNB is highly likely diagnostic for small pleural lesions with nodular morphology on either CT or US or with a pleural thickness of 4.5 mm or greater.