Morphological and Functional Analysis of Residual Lung After Pneumonectomy in Lung Cancer Surgery via 3D-CT Method

<b>Background:</b> Pneumonectomy is a major surgical option for non-small cell lung cancer (NSCLC). This study evaluates the predictive value of three-dimensional computed tomography (3D-CT)-based lung volume analysis for postoperative function and explores its potential role in preoperative planning, risk assessment, and surgical decision-making. <b>Methods:</b> We evaluated 59 NSCLC patients who underwent pneumonectomy. Pre- and 12-month postoperative spirometry results were compared with anatomical and 3D-CT-based predictions. Residual lung expansion was calculated, and patients were grouped by a 3D-CT-derived volume ratio of ≥1.2 or <1.2. <b>Results:</b> There was a significant correlation between 3D-CT-based predicted FVC and FEV1 and postoperative spirometric values (<i>p</i> < 0.001). The mean residual lung volume expansion ratio was 1.23. Patients with a ratio ≥1.2 had significantly higher postoperative FVC (<i>p</i> = 0.028). Lung expansion was observed in 81.4% of cases. Predicted postoperative FVC (<i>p</i> = 0.023) and FEV1 (<i>p</i> = 0.013) were significantly higher in patients with left pneumonectomy compared to right. <b>Conclusions:</b> 3D-CT-based lung volume calculation reliably predicts postoperative function and matches conventional methods. Contralateral lung expansion positively affects respiratory outcomes. Additionally, 3D-CT analysis supports preoperative planning and risk assessment, contributing to more accurate diagnosis and surgical decisions in NSCLC management.