Survival prediction for non-small cell lung cancer patients treated with CT-guided microwave ablation: development of a prognostic nomogram.

OBJECTIVES To explore the outcomes of CT-guided percutaneous microwave ablation (MWA) in non-small cell lung cancer (NSCLC) patients, and then develop an effective nomogram to predict the survival. METHODS NSCLC patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (3:1). The primary outcome measurement was overall survival (OS), whose predictors were identified by univariate and multivariate analyses in the training cohort. Then, a predictive nomogram was developed to predict the OS, with the predictive accuracy evaluated by C-statistic and receiver operating characteristic in both the training and validation cohorts. RESULTS A total of 234 patients (training cohort: n = 176; validation cohort: n = 58) and 271 tumors with a median OS of 17.0 ± 12.2 months were included. The predictors selected into the nomogram included tumor diameter (hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.37-3.30; p < 0.001), extrapulmonary metastases (HR, 1.77; 95% CI, 1.06-2.95; p = 0.030), tumor stage (HR, 1.38; 95% CI, 1.07-1.79; p = 0.013), tumor type (HR, 2.00; 95% CI, 1.48-2.72; p < 0.001) and post-MWA TKIs (HR, 0.55; 95% CI, 0.34-0.89; p < 0.001), based on the results of univariate and multivariate analyses. The C-statistic showed good predictive performance, with a C-statistic of 0.838 (95% CI, 0.779-0.897) internally and 0.808 (95% CI, 0.695-0.920) externally (training cohort and validation cohort, respectively). CONCLUSIONS The nomogram was effective in predicting the OS in NSCLC patients treated with MWA, and could be applied to identify patients who may benefit most from MWA and be helpful for clinical decision making.