Abstract:Objective To investigate the value of multi-slice spiral computed tomography (MSCT) quantitative technology in predicting the radiotherapy effect of lung cancer patients combined with chronic obstructive pulmonary disease (COPD). Methods A total of 74 lung cancer patients combined with COPD admitted from January 2017 to June 2018 who treated with intensity modulated radiotherapy (IMRT) was retrospective studied.MSCT was used to measure the diameter of bronchus lumen,the thickness of bronchus wall (WT),the area of bronchus lumen (AL),the ratio of wall thickness to external diameter (TDR),the ratio of wall area to total cross-sectional area (WA%),the emphysema index (EI),the ratio of pulmonary/aortic diameter (PA/A).According to the effect of radiotherapy,the patients were divided into two groups:the effective group and the ineffective group.The differences of imaging quantitative parameters between the two groups were compared,and the value of MSCT quantitative index in predicting the short-term effect of lung cancer patients with COPD was analyzed. Results Among 74 cases of lung cancer with COPD,1 case was complete remission (1.35%),29 cases were partial remission (39.19%),34 cases were stable (45.95%),10 cases were progressive (13.51%),and the total effective rate was 40.54%.FEV₁,FEV₁/FVC,FEV₁% in the effective group were higher than that in the ineffective group (t=10.475,4.454,3.925,all P<0.01).WT,TDR,WA%,PA/A and EI in the effective group were lower than those in the ineffective group,and AL was higher than those in the ineffective group (t=3.715,3.893,4.655,3.339,5.280,4.915,all P<0.01).WT,TDR and EI were the top three parameters of MSCT in predicting the comprehensive efficacy of COPD lung cancer.When the WT Youden index was the highest (0.821),the corresponding cutoff value was ≤ 1.36,the sensitivity and specificity of the predicted short-term efficacy were 86.67% and 95.45% respectively,and the area under the curve (AUC) was 0.911.When the TDR Youden index was the largest (0.809),the corresponding cutoff value was ≤ 0.24,the sensitivity and specificity of the predicted short-term efficacy were 90.00%,90.91%,and AUC was 0.907.When the EI Youden index was the largest (0.696),the corresponding cutoff value was ≤20.01,and the sensitivity and specificity of the predicted short-term efficacy were 90.00%,79.55%,and AUC was 0.878.WT,TDR,WA%,PA/A,EI were negatively correlated with FEV₁,FEV₁/FVC and FEV₁%(P<0.05，P<0.01).AL was positively correlated with FEV₁,FEV₁/FVC and FEV₁% (all P<0.01). Conclusion MSCT can be used to quantitatively measure the lung function and airway damage of lung cancer patients with COPD,which has a high value in predicting the short-term effect of radiotherapy.