Predictive factors for a successful diagnostic bronchoscopy of ground-glass nodules

INTRODUCTION Since the National Lung Screening Trial demonstrated the utility of low-dose computed tomography screening for lung cancer, the detection rate of ground-glass nodules (GGNs) has increased. Endobronchial ultrasound with a guide sheath (EBUS-GS) is widely performed to diagnose peripheral pulmonary lesions, but there are not enough reports on the predictive ability of EBUS-GS in diagnosing GGNs. The aim of this study is to investigate the predictive factors for a successful diagnostic bronchoscopy for GGNs. METHODS Consecutive patients who underwent diagnostic bronchoscopy for GGNs from September 2012 to January 2016 were enrolled in this study. From these, cases who underwent EBUS-GS were selected. They were reviewed and analyzed to examine the association between the diagnostic yield and the following clinical factors: lesion size, lobar position, location, consolidation-to-tumor ratio, visibility on X-ray, use of virtual bronchoscopy, bronchus sign, guide sheath size, and number of biopsies. RESULTS We enrolled 254 cases, of which 167 were diagnosed using EBUS-GS (65.7% diagnostic yield). Univariate analysis indicated that a positive bronchus sign was a significant factor for higher diagnostic yield (72.9% vs. 34.0%; P < 0.001). The use of virtual bronchoscopy also tended toward a higher yield, but the result was not significant (69.0% vs. 54.4%; P = 0.058). However, multivariate analysis indicated that both were significantly associated with higher diagnostic yield (P < 0.001, odds ratio [OR]: 5.35; P < 0.001, OR: 1.97, respectively). CONCLUSIONS Our results suggest that a positive bronchus sign and the use of virtual bronchoscopy are positive predictive factors for successful diagnostic bronchoscopy of GGNs.