18F-Choline PET/CT in biochemically relapsed prostate cancer

120 Objectives To evaluate the diagnostic role of 18F-Choline (18FC) PET/CT and to correlate its detection rate with PSA levels in biochemically relapsed prostate cancer patients. Methods 285 patients already treated with radical purpose with biochemical relapse and negative/inconclusive conventional imaging were evaluated by 18FC PET/CT. After i.v. injection of 18FC (3 MBq/Kg/bw) an early acquisition of the pelvis was performed followed by a whole body acquisition after 55 min. Scans were analyzed visually and by SUV analysis. Patients were subdivided on the basis of the following PSA (ng/ml) ranges : group I: PSA 10 (38 pts). Histologic/cytologic findings or imaging and biochemical follow up were taken as gold standard. Results The overall detection rate of 18FC was 52% (149/285 pts), raising with the raising of PSA, (being respectively 29%, 66%, 69%, 81%, 87% for the different 5 PSA groups). 27% of the patients (40/149) showed local relapse only, mainly confined to the prostatic bed (87%), and in 13% involving the locoregional lymph-nodes too, the remaining 109 pts (73% of all) showed a distant relapse (associated or not with local relapse as well), with bone spread in 76% of the cases (83/109). Conclusions The good detection rates (for both local and distant relapse), also in patients with relatively low PSA levels, raising with the raising of PSA, could suggest 18FC PET/CT as a useful tool for the restaging of the disease