Prediction of pulmonary function after major lung resection using lung perfusion scintigraphy with single-photon emission computed tomography/computed tomography.

Objective: Precise prediction of postoperative pulmonary function is extremely important for accurately evaluating the risk of perioperative morbidity and mortality after major surgery for lung cancer. This study aimed to compare the accuracy of a single-photon emission computed tomography/computed tomography (SPECT/CT) method that we recently developed for predicting postoperative pulmonary function versus the accuracy of both the conventional simplified calculating (SC) method and the method using planar images of lung perfusion scintigraphy.

Methods: The relationship between the postoperative observed % values of the forced expiratory volume in 1 second (FEV) or diffusing capacity for carbon monoxide (DL or DL') and the % predicted postoperative (%ppo) values of FEV, DL, or DL' calculated by the three methods were analyzed in 30 consecutive patients with lung cancer undergoing lobectomy.

Results: The relationship between the postoperative observed % values and %ppo values calculated by the three methods exhibited a strong correlation (Pearson r>0.8, two-tailed <0.0001). The limits of agreement between the postoperative % values and %ppo values did not differ among the three methods. The absolute values of the differences between the postoperative % values and %ppo values for FEV and DL' were comparable among the three methods, whereas those for DL of SPECT/CT were significantly higher than those of the planar method. Conversely, in patients with preoperative %DL' of <80% predicted, the absolute values of the differences between the postoperative %DL' and %ppoDL' of SPECT/CT tended to be smaller than those of the SC and planar methods.

Conclusion: The accuracy of SPECT/CT for predicting postoperative pulmonary function is comparable with that of conventional methods in most cases, other than in some patients with diffusion impairment.