Comparison of Predicted Postoperative Lung Function in Pneumonectomy Using Computed Tomography and Lung Perfusion Scans

BACKGROUND: Predicting postoperative lung function after pneumonectomy is essential. We retrospectively compared postoperative lung function to predicted postoperative lung function based on computed tomography (CT) volumetry and perfusion scintigraphy in patients who underwent pneumonectomy. METHODS: Predicted postoperative lung function was calculated based on perfusion scintigraphy and CT volumetry. The predicted function was compared to the postoperative lung function in terms of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)), using 4 parameters FVC, FVC%, FEV(1), and FEV(1)%. RESULTS: The correlations between postoperative function and predicted function based on CT volumetry were r=0.632 (p=0.003) for FVC% and r=0.728 (p<0.001) for FEV(1)%. The correlations between postoperative function and predicted postoperative function based on perfusion scintigraphy were r=0.654 (p=0.002) for FVC% and r=0.758 (p<0.001) for FEV(1)%. The preoperative Eastern Cooperative Oncology Group (ECOG) scores were significantly higher in the group in which the gap between postoperative FEV(1) and predicted postoperative FEV(1) analyzed by CT was smaller than the gap analyzed by perfusion scintigraphy (1.2±0.62 vs. 0.4±0.52, p=0.006). CONCLUSION: This study affirms that CT volumetry can replace perfusion scintigraphy for preoperative evaluation of patients needing pneumonectomy. In particular, it was found to be a better predictor of postoperative lung function for poor-performance patients (i.e., those with high ECOG scores).