Correlation of 11C-choline PET and PSA values in patients with prostate cancer and biochemical relapse after primary treatments

5073 Background: 11C-choline PET has demonstrated promising results in the evaluation of suspected recurrence after a primary treatment in prostate cancer (PC) patients (pts). However in pts with asymptomatic biochemical relapse (BR), the timing of PET scan is a subject of controversy. Most authors argue against performing PET scan for rising PSA values <5 ng/ml. Aim of our study was to evaluate if there is a PSA cut-off that significatively correlates to 11C-choline PET positivity. Methods: 68 pts with rising PSA after primary treatment underwent 11C-choline PET. Median age was 68 yrs (range 43–84). Median PSA at the time of PET scan was 2.91 ng/ml (range 0.12- 71.60). Primary treatments were: 27 (40%) radical prostatectomy (RP), 22 (32%) external-beam radiation therapy (EBRT), 13 (19%) RP + adjuvant EBRT, 6 (9%) hormonal therapy. Results: 11C-choline PET was positive in 39/68 pts (57%) and negative in 29/68 (43%). Median PSA values were 1.18 ng/ml (range 0.12–6.47) and 5.14 ng/ml (range 1.33–71.60) in p...