PO-519 Can PSA level and its change in time predict localization of proastate cancer relapse, assesed by PET-CT with 18F-Choline?

IntroductionPatients with prostate cancer after treatment are routinely monitored by Prostate Specific Antigen (PSA) level evaluation and occasionally referred to Positron Emission Tomography (PET-CT) for verification and assessment of relapse and/or metastases. The aim of our study was to evaluate the value of measurements of PSA level and its changes by quantitative PET parameter Standardised Uptake Values (SUV) in patients with recurrent prostate cancer.Material and methodsWe retrospectively collected PET-CT, performed using Discovery IQ scanner (GE Healthcare), 3 and 20 min after injection of 18F-choline (3 MBq/kg). Biopsy-proven prostate cancer patients undergoing a PET-CTscan due to the suspicion of recurrence after treatment were enrolled into the study and subgroup of subjects with recurrent disease, confirmed by positive PET-CT were analysed. Plasma levels of PSA at the time of PET-CT and PSA level change per month (ΔPSA) prior to the scan were analysed, together with SUVmax. Results are shown as median values and interquartile range.Results and discussionsThe study cohort included three subgroups, diagnosed by visual PET-CT evaluation: 27 patients with only local cancer recurrence (R), 110 with distant metastases (M) and 35 subjects with both local recurrence and metastases (R+M). PSA levels at the time of PET-CT were similar in R and M groups: 5,00 (2,98–10,30) ng/ml and 3,90 (1,27–14,08) ng/ml, but significantly (p