The diagnosis of peripheral lung lesions: transbronchial biopsy using a radial probe endobronchial ultrasound

Background: Radial probe endobronchial ultrasound (RP-EBUS) has been used in the diagnosis of peripheral lung lesions (PLLs). We reviewed the traditional modality of transbronchial biopsy using RP-EBUS as well as recent developments in improving the diagnostic yield.Current Concepts: Until now, the forceps biopsy of PLLs has played a key role in acquiring tissue samples during the RP-EBUS procedures. Forceps biopsy is a safe and minimally invasive procedure; however, its diagnostic yield was reported to be around 70%, which is significantly lower than that of percutaneous needle aspiration or biopsy. So far, various studies have been conducted to improve the diagnostic yield of the RP-EBUS procedure. The combination of novel navigation systems, such as virtual or electromagnetic navigation bronchoscopies, for locating PLLs in the complex bronchial tree has increased the diagnostic yield of the RP-EBUS procedure. Moreover, newly developed ancillary devices, such as the PeriView FLEX needle or cryobiopsy, as well as traditional modalities such as the guide sheath and brushing cytology, can improve the outcomes of the RP-EBUS procedures. Concerning the bronchoscope size, it has been confirmed that a 3 mm-diameter ultrathin bronchoscope has a higher diagnostic yield than a 4 mm-diameter thin bronchoscope.Discussion and Conclusion: RP-EBUS is a safe and useful method to diagnose PLLs. When traditional and novel modalities are appropriately combined, the diagnostic yield can be increased.