Using quantitative CT to predict postoperative pulmonary function in patients with lung cancer.

Background At present, the therapy for patients with lung cancer that achieves a high rate of cure is surgical resection at an early stage of the disease. The aim of this study is to evaluate quantitative computed tomography (QCT) for predicting postoperative pulmonary function in patients with lung cancer. Methods The data of thirty-one patients with lung cancer who underwent both pulmonary functional tests and QCT scan before operations were collected. A CT program was used to quantify the volume of whole lung parenchyma with attenuation of -910 HU to - 600 HU, which was defined as total functional lung volume (TFLV). Similarly, the volume of lung (lobes or segments) with attenuation of -910 HU to -600 HU was defined as regional functional lung volume ( RFLV). Forced vital capacity (FVC), forced expiratory volume in first second (FEV 1 ), FVC% and FEV 1 % (ratio to reference values of the matched population) were obtained from preoperational pulmonary functional tests. According to the formula: predicted FVC ( pre-FVC ) = preoperative FVC x [ 1 - (RFLV/TFLV) ] ; predicted FEV 1 (pre-FEV 1 ) = preoperative FEV 1 x [1 - ( RFLV/ TFLV) ] , we obtained values of predicted FVC, predicted FEV 1 , predicted FVC% (pre-FVC/reference values of the matched population), and predicted FEV 1 % (pre-FEV 1 /reference values of the matched population). The paired t test and Pearson correlation test were used to assess significance of differences and correlations between CT predicted values and postoperative measured results of FVC, FEV 1 , FVC% and FEV 1 %. Results QCT predicted values correlated well with postoperative FVC, FEV 1 , FVC% and FEV 1 % (r = 0. 873, 0. 809, 0. 849 and 0. 801 respectively, all P <0. 01). Conclusions QCT is an effective and accurate way to predict postoperative pulmonary function in patients undergoing pulmonary resection, regardless of the patients' preoperative pulmonary functional status.