Fig. 4

The graph shows Kaplan–Meier curves for disease-free survival according to the corrected 3D-IRA at the early phase of contrast-enhanced CT. a Patients with tumors showing 3D-IRA > 5.88 had a significantly better prognosis than those with tumors showing 3D-IRA < 5.88 (p = 0.017). b Patients with adenocarcinomas, c patients with squamous cell carcinomas, d patients with other subtype tumors showing 3D-IRA > 5.88 had a better prognosis than those with tumors showing 3D-IRA < 5.88 although there was no significant difference (p = 0.224, p = 0.126, and p = 0.109, respectively)