Fig. 1.

This 65-year-old patient underwent ¹⁸F-fluorocholine (FCH) PET/CT for biochemical recurrence of prostate cancer (BCR) sPSA = 3 ng/mL, 9 years after total prostatectomy (Gleason score 3 + 4, pT3b N0 M0). a From left to right: PET, CT, PET/CT fusion, MIP. FCH PET/CT showed foci of moderate intensity in the right seminal vesicle (SUVmax = 2.3), and in left ilio-obturator (SUVmax = 3.3) and right external iliac lymph nodes (SUVmax = 2.6). Overall, the result of FCH PET/CT was considered equivocal. b PSMA-11 PET/CT was requested before proposing a new treatment. Its early dynamic images showed a clear focus in the right seminal vesicle (SUVmax = 7.7), without any abnormal foci in the two lymph nodes that mildly took up FCH. c Due to the urinary excretion of PSMA-11 and the high activity in the bladder, the focus in the right seminal vesicle was no longer visible on the images acquired 70 min post-injection. Radiation therapy limited to the prostate lodge and the right seminal vesicle was completed 3 months later; sPSA was < 0.01 ng/mL and remains undetectable 2 years later. This case illustrates the added value of early acquisition for PSMA-11 PET/CT to avoid the interference of the radioactive bladder, and its specificity to rule out invasion of lymph nodes, since no recurrence was confirmed in the FCH-equivocal PSMA-11-negative pelvic lymph nodes after more than 2 years