Fig. 4.

Indeterminate findings on prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT). A 58-year-old man with history of biochemical recurrence undergoing [¹⁸F]-DCFPyL PET/CT. a Whole-body maximum intensity projection image demonstrates mild radiotracer uptake in a left-sided rib (arrowhead). b Axial CT, c axial PET, and d axial PET/CT also demonstrate the mild radiotracer uptake at this site (red arrowheads), which was classified as indeterminate for prostate cancer (PSMA-RADS-3B). e Axial CT, f axial PET, and g axial PET/CT showing moderate radiotracer uptake in a right peri-rectal lymph node (red arrows). As this site of radiotracer uptake does not show a corresponding pathologically enlarged lymph node on e axial CT, this finding was classified as PSMA-RADS-4. The overall scan score was, therefore, also PSMA-RADS-4