Fig. 1

Maximum intensity projection (MIP) images of a patient with biochemical recurrence of prostate cancer on A) [68Ga]Ga-PSMA-11 PET/CT 1 h post-injection and B) (right to left) [89Zr]Zr-PSMA-617 PET/CT 1 h, 24 h, and 48 h post-injection. As denoted by the red arrows, a lesion faintly visible on the [68Ga]Ga-PSMA-11 scan, although not clearly discernible on the 1-hr [89Zr]Zr-PSMA-617 image, was clearly discernible as a presumed bone metastasis on the 24-hr and 48-hr [89Zr]Zr-PSMA-617 scans. Supporting the visual findings, [89Zr]Zr-PSMA-617 uptake, reflected by C) the SUVmax curve for the lesion, showed a sharp increase from 1 to 24 h, and then a slower increase from 24 to 48 h