Diagnostic yield of radial probe endobronchial ultrasonography-guided transbronchial biopsy without fluoroscopy in peripheral pulmonary lesions: A systematic review and meta-analysis

Purpose: Although radial probe endobronchial ultrasound (R-EBUS) has been used to investigate peripheral pulmonary lesions (PPLs), its diagnostic performance without fluoroscopy remains unclear. We sought to determine the diagnostic yield of R-EBUS-guided transbronchial biopsy (TBB) without fluoroscopy. Methods: We performed a systematic literature review using Pubmed, Embase, and the Cochrane Central Register. Then, we performed a proportional meta-analysis to determine the diagnostic yield of this modality. Subgroup and meta-regression analyses were used to identify factors affecting the performance of R-EBUS-guided TBB without fluoroscopy. Results: We identified 31 studies consisting of a total of 6491 patients. Pooled overall diagnostic yield of R-EBUS-guided TBB without fluoroscopy was 0.70 (95% confidence interval [CI], 0.67–0.74). There was significant heterogeneity across studies (I² = 89.45%, p < 0.001). In subgroup and meta-regression analyses, air bronchus sign on chest computed tomography scans, larger size PPLs, probe location within lesions, and heterogeneous echogenicity were associated with significantly higher diagnostic yield. Diagnostic yield from the upper lobe was statistically lower than that from the middle and lower lobes. Pooled pneumothorax rate was 0.01 (95% CI, 0.01–0.01, I² = 63.51%, p < 0.001). Conclusions: R-EBUS-guided TBB without fluoroscopy appears to be a relatively useful tool with a low pneumothorax rate for the diagnosis of PPLs. Factors mentioned above may affect the diagnostic yield of this tool. Because of substantial between-study heterogeneity, our results should be interpreted with caution.