Fig. 1

Representative cases for the assessment of re-biopsy feasibility

Progressive or relapsing sites were evaluated for the feasibility of re-biopsy according to the criteria shown in Table 1. a Lung nodule (long diameter ≥ 2 cm) with a responsive bronchus leading to the center of the lesion (category A for trans-bronchial biopsy [TBB]). b Lung nodule adjacent to the nearest bronchus (category A for TBB). c Lung nodule not reaching a responsive bronchus but accessible by CT-guided needle biopsy (CTNB) (long diameter < 1 cm and ≤5 cm distant from the thoracic wall category B for CTNB). d Diffuse pulmonary infiltration presenting a lymphangitic distribution (category A for trans-bronchial lung biopsy [TBLB]). e Small pulmonary metastases (not feasible or extremely difficult for TBB or CTNB; category C). f Brain metastases (surgical resection required; category C). g Solitary pleural metastasis (long diameter ≤ 1 cm; category B for CTNB). h Para-aortic lymph node metastasis, front and adjacent to the abdominal aorta (CTNB is highly unsafe; category C). i Bone metastasis with extra-osseous invasion (category A for CTNB)