Performance of radial endobronchial ultrasound for peripheral pulmonary lesions without automation technology in tuberculous endemic region: real-world experience in a single institution over 6 years

Peripheral pulmonary lesions (PPLs) in tuberculous endemic regions present a unique diagnostic challenge, as tuberculous PPL can mimic malignancy and potentially delay diagnosis for both conditions without a confirmatory investigation. While bronchoscopic biopsy using radial endobronchial ultrasound (rEBUS) guidance is becoming more common among pulmonologists, it is often performed with additional automation technology such as virtual bronchoscopic and electromagnetic navigation. This study aimed to evaluate the performance of rEBUS without such automation technology over a 6-year period in our institution. Retrospective chart review of all adult patients undergoing rEBUS-guided transbronchial biopsy for PPL in our institution over 6 years duration (October 2016 to December 2022). A total of 551 PPLs were included with median target lesion size of 2.70 (interquartile range, 2.10-3.70) cm. In total, 84.2% of lesion demonstrated direct bronchus sign with 46.3% demonstrating concentric rEBUS orientation. The overall diagnostic yield was 78.8% [95% confidence interval (CI): 75.1-82.1%], with 1.1% rate of pneumothorax. Among the conclusive cases, 62.7% were malignant while 37.3% were tuberculous. Bronchus sign [adjusted odds ratio (adj. OR): 2.268] and concentric rEBUS orientation (adj. OR: 3.426) are independent predictors for conclusive procedure. The sensitivity of rEBUS for malignant and tuberculous disease was 85.27% (95% CI: 80.89-88.97%) and 71.77% (95% CI: 62.99-79.49%) respectively. A significant improving trend of diagnostic yield over time with reduction of median PPL size was observed with introduction of cryobiopsy and thin bronchoscopy into rEBUS service. rEBUS without automation technology remains relevant and useful in this era. rEBUS provides a rapid and safe diagnosis of PPL which may translate into better patient care.