Utility of thoracic ultrasound for detecting malignant pleural effusion: a systematic review and meta-analysis

Abstract

Introduction: Although the sensitivity of cytology is low, morphological findings of thoracic ultrasound (TUS) can identify malignant pleural effusion (MPE).

Objectives: This study aimed to evaluate if TUS findings could help rule-in or rule-out MPE.

Methods: We registered in the University hospital Medical Information Network Clinical Trials Registry as 000039136. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and the International Clinical Trials Registry Platform up to December 2019 for prospective and retrospective cohort studies, case series, and case–control studies. Two authors independently screened articles, evaluated the risk of bias and applicability using the modified Quality Assessment of Diagnostic Accuracy Studies-2, then created a forest plot. Because of heterogenous sensitivity and specificity of all TUS findings other than pleural nodularity, we only calculated the pooled sensitivity and specificity with a bivariate random-effects model of pleural nodularity. We evaluated the overall certainty of evidence with the Grading of Recommendations, Assessment, Development, and Evaluation approach.

Results: Seven prospective studies, including 840 patients, were reviewed. All studies were conducted at university hospitals by experienced radiologists or pulmonologists. All TUS findings had a low sensitivity. The pooled sensitivity and specificity of the pleural nodularity were 42.5% (95% Cr-l, 25.3%–61.6%) and 96.9% (95% Cr-l, 93.2%–98.6%). The overall certainty of evidence was moderate.

Conclusions: TUS findings would not help rule-out MPE. Pleural nodularity could rule-in MPE for repetitive thoracentesis or further invasive examinations.