(18)F-choline PET/CT for early detection of metastases in biochemical recurrence following radical prostatectomy.

Objective: Salvage radiotherapy (SRT) for biochemical recurrence (BCR) following radical prostatectomy (RP) should if possible be added at a prostate-specific antigen (PSA) level of <1-2 ng/mL. The value of positron emission tomography combined with computed tomography (PET/CT) at such low PSA values is not defined. The purpose was to determine what proportion of a well-defined cohort of hormone-naïve patients who were candidates for early salvage radiotherapy had (18)F-choline PET/CT findings suggesting metastases.

Methods: Patients with untreated BCR following RP, PSA <2 ng/mL, and Gleason score ≥7 or PSA doubling time ≤6 months underwent (18)F-choline PET/CT. Focal choline uptake in lymph nodes or skeletal sites was recorded.

Results: PET/CT indicated metastases in 16 (28 %) of 58 patients. In five (9 %) patients, the scans suggested bone metastases, and in 11 (19 %) patients, the scans suggested regional lymph node metastases only. For patients with PSA levels <1.0 ng/mL, the PET/CT scans indicated metastatic recurrence in 25 %.

Conclusions: (18)F-choline PET/CT may be valuable for selecting patients with BCR following RP for SRT or experimental treatment of oligometastases, even at low PSA values.