To Evaluate the diagnostic performance of  18 F-choline PET-CT in staging prostate cancer (PC) and the use of esta Whether imaging modality changes the therapeutic decision in Patients with previously staged by conventional imaging. The secondary aim was to determine the prognostic factors associated with positive choline PET-CT findings in both detections of disseminated disease and changes in the therapeutic indication

Multicenter, retrospective, observational study of 269 patients with PC. Mean age was 69 ± 9.2 years. Of the 269 patients, 62 (23%) had high-risk localized PC (group 1), 118 (43.9%) biochemical failure after radical prostatectomy (group 2), and 89 (33.1%) biochemical failure after radiotherapy (group 3) . None of the patients showed clear evidence of distant disease on computed tomography or bone scans.

The following potential prognostic factors were assessed: PSA level at diagnosis; primary and secondary Gleason; Gleason score (GS); clinical and pathologic T and N stage; number of positive cylinders in the biopsy; presence of vascular or lymphatic invasion ; status of surgical margins; androgen deprivation therapy (ADT); time to biochemical recurrence; and PSA, PSA doubling time (PSADT), and PSA velocity (PSAV) at failure.

Results

The mean PSA by groups was group 1: 31.22 ng / ml, group 2: 2.52 ng / ml and group 3: 5.85 ng / ml. The tumor detection rate with 18 F-choline PET-CT was 74% (group 1: 85.5%, group 2: 55.1% and group 3: 91%).

Prognostic factors for positive 18 F-choline PETCT were identified only in group 2: PSA at failure and PSADT. 18 F-choline PETCT changed the therapeutic indication in 62.8% (group 1: 71%, group 2: 55.2% and group 3: 70.1%).

The prognostic factors for a change in treatment were identified only in group 1: secondary Gleason ≤ 4 and GS ≤ 7 and in group 2: PSA at failure, PSA nadir after surgery and pathologic stage N0. 18F-choline PET-CT identified lymph node and / or metastatic disease in 32.7% (group 1: 25.8%, group 2: 29.7% and group 3: 41.6%).

Prognostic factors for detecting lymph I was identified in the group 2: PSA failure ≥ 1.37 ng / ml and PSADT <4 months and in the group 3: PSADT <4.6 months and time to failure <5 years.

These findings support the clinical use of 18 F-choline PET-CT in-staging high-risk patients with a secondary Gleason ≤ 4 and GS ≤ 7, in restaging patients with biochemical recurrence after RP if PSA at failure ≥ 1.37 ng / ml or PSADT ≤ 4 months and in patients with biochemical failure after RT, if PSADT ≤ 4.6 months and time to failure <5 years, because it determines a change in the therapeutic indication.