Diagnostic utility of radial endobronchial ultrasound–guided lung biopsy without guide sheath or fluoroscopy: a retrospective study

Abstract

Background
Peripheral pulmonary lesions pose a diagnostic challenge due to inaccessibility by conventional bronchoscopy and complications associated with transthoracic needle biopsy. Radial endobronchial ultrasound (R-EBUS) enables localization of peripheral nodules; however, its utility without guide sheath or fluoroscopy remains under-evaluated in resource-limited settings.


Methods
We retrospectively analysed 45 patients who underwent R-EBUS-guided lung biopsy without the use of a guide sheath or fluoroscopy at two tertiary centres over one year. R-EBUS–guided biopsy was performed using the distance method (where the distance from bronchoscope tip to lesion is measured using the radial probe and biopsy instruments are advanced to the same depth). R-EBUS-guided forceps biopsy was performed for concentric lesions while R-EBUS-guided cryobiopsy for eccentric lesions. Diagnostic accuracy, sensitivity, specificity, and predictive values were calculated using histopathological findings as the reference standard. Lesion characteristics— CT bronchus sign (positive vs. negative), size (≤ 30 mm vs. > 30 mm), location (central vs. peripheral), and EBUS pattern (concentric vs. eccentric)—were correlated with diagnostic yield.


Results

The overall diagnostic accuracy was 82.2%, sensitivity 74.2%, and specificity 100%. The positive and negative predictive values were 100% and 63.6%, respectively. Concentric lesions demonstrated significantly higher malignant diagnostic yield (88.9%) compared to eccentric lesions (
p
 = 0.02). Larger lesions (> 30 mm) and lesions with a positive CT bronchus sign demonstrated significantly higher malignant diagnostic yield. Adenocarcinoma was the most common malignancy (40.0%), while granulomatous inflammation, including tuberculosis, was the predominant benign finding (17.8%).



Conclusion
R-EBUS-guided forceps biopsy and cryobiopsy using the distance method without guide sheath or fluoroscopy provides high diagnostic accuracy and is safe, cost-effective, and suitable for routine clinical use. Concentric lesions predict higher diagnostic success, and cryobiopsy serves as an effective adjunct for eccentric lesions.