Impact Of The F-18- Pet/Ct Scan In The Management Of Patients With High-Risk Or Intermediate-Risk Prostate Cancer At Initial Diagnosis Or At Recurrence.

87 Background: It is reported that a Fcholine Positron Emission Tomography (PET/CT) scan can change the management of the patients with prostate cancer up to 20% of the cases. The aim of this study was to evaluate the impact of 18FCholine PET/CT when its indication was taken by a multi-disciplinary staff in case of initial diagnosis or in case of recurrence. Methods: This retrospective study involved 84 patients between May 2013 and July 2014. After a selective approach 86 18F-PET/CT were performed consecutively: 37 (43%) for the initial staging and 49 (57%) in biochemical failure. The acquisition protocol included a pelvic dynamic scan after injection of 4 MBq/kg of 18FCholine followed by a whole-body scan. Mean age, PSA level and Gleason score were respectively in relapse and initial staging: 71 years (59-82), 4.9 (0.12-32.8), 7 (6-9) and 63 years (48-76), 16 (2.42-55) and 8 (6-10). Results: In initial diagnosis, prostate cancer was identified in all the patients on PET/CT. Local disease was seen in 23/37 scans (62.2%); loco-regional node involvement in 8 (21.6%) and metastatic disease in 6 (16.2%). PET/CT confirmed the therapeutic decision in 48.6% of cases and led to a therapeutic modification in 43.2% of cases,avoiding radical prostatectomy and lymphadenectomy in 25% of cases or modifying the extend of radiotherapy (25%) . In biochemical recurrence, PET/CT showed relapse in the prostatic area in 14 patients (28.6%); abnormal pelvic lymph nodes in 10 cases (20.4%) and distant metastases in 18 patients (36.7%). It failed to identify the cause of relapse in 7 cases (14.3%). PET/CT confirmed the therapeutic approach in 24.5% and led to a therapeutic change in 61.2% of cases The diagnostic performance of the FCholine PET/CT scan on nodes, according to the pathological results were: sensitivity 80 %, specificity 84.6%, positive predictive value 66.7% and negative predictive value 91.7 % Conclusions: A rigorous selection of the patients before the realization of a FCholine PET/CT scan in the management of a prostate cancer can increase the diagnostic performance and provide a better impact. In this study the treatment modification affected 54.8% of the patients.