Ultrasound-guided Cryobiopsy of Mediastinal/Hilar Lymph Nodes

EBUS-guided cryobiopsy of mediastinal and hilar lymph nodes has shown to be a useful diagnostic tool to obtain tissue for histological analysis and further targeted therapies in lung malignancies. Due to the large size and better quality of the tissue samples, a higher diagnostic yield than with transbronchial needle aspiration (TBNA) can be expected, especially in non-solid tumors. In previous studies different biopsy protocols were used. The freezing time of cryoprobe (which defines the sample sizes) ranged from 3 to 7 s and the number of biopsies was between 1 and 4 samples. It is therefore unclear what freezing times and biopsy frequency are required to obtain the best histological information. This study will analyze whether the freezing time influences the diagnostic yield in CB of mediastinal lymphadenopathies. Additionally we will evaluate the influence of the number of biopsies on the diagnostic yield.