Fig. 3

Decision curve for prediction of LNM for T1/T2 gallbladder cancer. Black line: assume no patient will have LNM; gray line: assume all patients will have LNM; red line: binary decision rule based on tumor differentiation alone; blue line: binary decision rule based on T stage alone; green line: binary decision rule based on tumor size alone; purple line: decision based on nomogram. Probability thresholds for differentiation, T stage, tumor size and nomogram are 0.23–0.49, 0.03–0.45, 0.28–0.51, 0.02–0.63, respectively