Fig. 4

Kaplan–Meier estimates of PFS according to the number of focal, hypermetabolic lesions (Fx) at baseline (A) and follow-up PET/CT (B). At baseline, the patients are divided according to the four groups of the Fx score (A), while at follow-up, they are dichotomized in those having no lesions (F1), and those presenting with at least one lesion (F2–F4). The numbers of patients at risk in each group and for the respective time-points are shown below the plots