Inclusion Criteria:  Selection criteria for VATS segmentectomy in the present study were as follows:  (I) patients with single peripheral GGO lesion considered suspicious for malignancy;  (II) the lesion <2 cm in diameter and with at least one of the followings:  (i) pure adenocarcinoma in situ (AIS) histology;  (ii) nodule has ≥50% ground-glass appearance on high resolution CT;  (iii) radiologic surveillance conforms a long doubling time (≥400 days).  Exclusion Criteria:  (I) patients with insufficient cardiopulmonary function;  (II) other contraindication for segmentectomy.