Outcomes of radial probe endobronchial ultrasound-guided transbronchial lung cryobiopsy using guide sheath and the target fixing technique.

Background: The need to obtain high-quality samples from lung nodule suspected malignancy is continuing to rise. This study aimed to evaluate the diagnostic yield of radial probe endobronchial ultrasound-guided transbronchial lung cryobiopsy (RP-EBUS-TBLC) using guide sheath (GS) for lung lesions suspected of malignancy on computed tomography (CT). Methods: This retrospective observational study included patients who underwent RP-EBUS-TBLC using GS between January 2023 and April 2025 in South Korea. We introduced Dohyun's method (a target-fixing technique) used to overcome the respiratory gating of the target during semi-real-time biopsy. After identifying the target lesion, the bronchoscope was inserted and fixed within the segment; the position was maintained while RP-EBUS was withdrawn, and the lesion stability during respiration was confirmed. Results: The final inclusion of 120 patients was analyzed. After the exclusion of patients with an indeterminate diagnosis, the final diagnostic yield was 94.8% (90.8% to 95.0% considering indeterminate diagnosis). The sensitivity and specificity were 93.7% and 100.0%, respectively. Pneumothorax occurred in 5.0% (6/120) of patients. Grade 3 or higher bleeding was observed in two patients, and a Fogarty balloon catheter was preemptively used in five patients at the operator's discretion. In the multivariate logistic regression, the CT-bronchus sign emerged as the only significant factor associated with pathological confirmation. However, lesion size, eccentricity, and lower lung distribution were not significantly associated. Conclusions: RP-EBUS-TBLC using GS demonstrated high diagnostic yield and acceptable safety for the diagnosis of lung lesions. Dohyun's method may facilitate continuous targeting of lesions during semi-real-time biopsy, particularly in cases where respiratory motion and non-within-RP-EBUS target lesions present challenges.