X. Zhenga (Prof), L. Zhangb (Prof), C. Zhongc (Prof), F. Xiea (Dr), S. Lic (Prof), G. Wangb (Prof), J. Sun*a (Prof)

a Department of Respiratory Endoscopy, Department of Respiratory and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai Engineering Research Center of Respiratory Endoscopy, Shanghai, CHINA ; b Department of Endoscopy, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, CHINA ; c State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangdong, CHINA

* xkyyjysun@163.com

Xiaoxuan Zheng, Lei Zhang and Changhao Zhong contributed equally to this research.

Background: Transbronchial sampling of peripheral pulmonary lesions (PPLs) is routinely performed under fluoroscopy. However, advanced ancillary techniques have become available, such as virtual bronchoscopic navigation (VBN) and radial endobronchial ultrasound with a guide sheath (rEBUS-GS). This study was performed to determine whether the diagnostic utility of VBN and rEBUS with a GS is similar with or without fluoroscopy.

Methods: This multicenter non-inferiority trial randomized patients with PPLs suspicious of malignancy to a VBN-rEBUS-GS group or a VBN-rEBUS-GS-fluoroscopy group at 3 centers. The bronchoscope was advanced to the targeted bronchus under VBN guidance and the rEBUS-GS was inserted to confirm the lesion, with or without fluoroscopy. The primary endpoint was the diagnostic yield, and the margin used to establish non-inferiority was -10%. The secondary endpoints were the times for rEBUS, GS, and the total operation. Complications were also recorded.

Results: 496 subjects were assessed from September 2018 to July 2019 and 436 subjects were enrolled in the study. 426 subjects were finally analyzed, 212 in non-fluoroscopy-guided group and 214 in fluoroscopy-guided group. The adjusted diagnostic yield in the non-fluoroscopy-guided group (84.6%) was not inferior to that in the fluoroscopy-guided group (84.8%), with a diagnostic difference of -0.2% (95% CI: -6.7%, +6.3%). Multivariable analysis confirmed that bronchus sign and lesion nature were valuable diagnostic predictors in non-fluoroscopy-guided group. Relative to the fluoroscopy-guided group, the non-fluoroscopy-guided group had shorter rEBUS, GS, and total operation times. No severe complications occurred in either group.

Conclusion: Transbronchial diagnosis of PPLs using VBN-rEBUS-GS without fluoroscopy is a safe and effective method that is non-inferior to VBN-rEBUS-GS with fluoroscopy. Positive bronchus sign and malignant nature are associated with high diagnostic yield in VBN-rEBUS-GS without fluoroscopy for the diagnosis of PPLs.

Disclosure of funding source(s): none