[A comparative study of radial ultrasound combined with cryobiopsy and forceps biopsy under thin-layer CT navigation in the diagnosis of malignant peripheral lung lesions].

Objective: Comparative study on the application value of bronchial ultrasound combined with different biopsy methods under thin-layer CT navigation in the diagnosis of malignant peripheral lung lesions. Methods: A retrospective analysis of patients with suspected malignant peripheral lung lesions identified by chest CT from January 2019 to September 2024 at the Cancer Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College, and Xianyang Central Hospital, who underwent routine bronchoscopy with negative results (209 cases). These patients were diagnosed using bronchial ultrasound under thin-layer CT navigation. The cases were divided into a cryobiopsy group (127 cases) and a conventional forceps biopsy group based on the biopsy method (82 cases). The diagnostic rates of the two groups were statistically analyzed, along with factors influencing the diagnostic rates. The tissue size obtained from both groups was compared, and the occurrence of complications was summarized. Results: This study included 209 cases with 216 peripheral lung lesions. A total of 209 cases with 210 lesions were successfully located through thin-slice CT guidance, resulting in a guiding success rate of 97.2% (210/216). Among the 130 lesions in the cryobiopsy group, 78 lesions were diagnosed as lung malignancies, with a diagnostic rate of 82.1% (64/78) for cryobiopsy in lung malignant lesions. In the forceps biopsy group, 46 of the 86 lesions were diagnosed as lung malignancies, with a diagnostic rate of 87.0% (40/46) for forceps biopsy in lung malignant lesions. There was no statistically significant difference between the two diagnostic rates (P=0.473). The average longest diameter of tissue obtained by cryobiopsy was (6.11±0.23) mm, while the average longest diameter of tissue obtained by forceps biopsy was (1.58±0.43) mm. There was a statistically significant difference in tissue longest diameter between the two groups (P＜0.001). When the distance from the bronchoscopic tip to the lesion was ≥3 cm and the most distal bronchus visible under bronchoscopy was ≤5th generation, the diagnostic rate of forceps biopsy was higher [83.3%(25/30) and 94.1%(32/34)] than that of cryobiopsy [79.3%(23/29) and 78.0%(46/59)], and the difference was statistically significant (P＜0.05). Regarding complications, one case (1.3%, 1/78) of clinically significant complications occurred in the cryobiopsy group, while no complications occurred in the forceps biopsy group. Conclusions: Under thin-layer CT navigation, bronchial ultrasound combined with different biopsy methods demonstrates a high diagnostic rate for malignant peripheral lung lesions and is safe to operate. Cryobiopsy allows for the collection of larger tissue specimens.