Spss software ver 18

SPSS software ver. 18.0.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis, and the p-value significance was set at 0.05. Baseline characteristics were summarized with descriptive statistics, including mean, standard deviation, and 95% confidence interval) for continuous variables, and frequencies for categorical variables. Fisher exact test was computed for comparisons of categorical variables (gender, primary event, and coexisting hypoperfusion), and Mann-Whitney test were used for comparisons of continuous variables (age, symptom duration, and K-MBI). To compare CNT scores between groups, Mann-Whitney test was used.

The statistical analysis was performed using the SPSS software ver. 18.0.0 (SPSS Inc. Chicago, IL, USA). A p-value less than 0.05 was considered statistically significant. Categorical and continuous data were compared between the groups using Fisher exact test and Student t-test, respectively. The survival curves were generated using the Kaplan-Meier method and compared with log-rank test. The Cox proportional hazards model was adopted for multivariate analysis. To adjust for confounding factors between two groups, we incorporated a propensity score in the Cox proportional hazards model, which estimates the tendency to perform NADT. The propensity score was the linear predictor from a multivariate binary logistic model in which the response variable was NADT and the covariates were patient's age, the Eastern Cooperative Oncology Group performance status, clinical T stage, Gleason score, and pretreatment PSA.