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

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.

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.

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).

Our results suggest that a positive bronchus sign and the use of virtual bronchoscopy are positive predictive factors for successful diagnostic bronchoscopy of GGNs.