However, the per protocol set was generated sufficiently to ensure that the data would exhibit treatment effects according to the underlying scientific model. Moreover, we did not account for the amount of resected lung parenchyma. Postoperative lung volume is influenced by the location and size of the mass. The lobe of operation affected postoperative lung volume, even if the parenchyma removed, which is larger during lower lobectomy, the reduction of postoperative total lung volume is less than that resulting from an upper lobectomy [16]. No difference in the frequency of lobectomy sites was observed between the two groups (Table 1). We measured tumor size using radiological findings and no significant difference were detected between the groups (3.5 cm [range, 1.8-5.2 cm] vs. 2.5 cm [range, 1.4-3.2 cm]; p=0.281). Therefore, the reductions in tumor size and lung volume probably did not affect the pulmonary rehabilitation in this study. We could have evaluated the therapeutic influence of pulmonary rehabilitation more objectively if we had compared the quantities functional lung tissue removed or diaphragm movement. Despite these limitations, we revealed the advantage of systemic pulmonary rehabilitation in patients who underwent lung resection surgery.