Dual Tracer 11C-Choline and FDG-PET in the Diagnosis of Biochemical Prostate Cancer Relapse After Radical Treatment

The purpose of this study was to evaluate a dual tracer 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) and C-11-choline positron emission tomography (PET) protocol in the detection of biochemical prostate cancer relapse. Seventy-three patients (median Prostate Specific Antigen (PSA) Test value 2.7 ng/ml (1.1-5.4)) after radical treatment. PET scans were performed by means of a ECAT-Exact HR+ in the first 18 patients and in a PET/computed tomography Biograph II in the remaining 55 patients. The sensitivity of C-11-choline and FDG was 60.6% and 31%. In PSA levels over 1.9 ng/ml, sensitivity increased to 80% and 40%, respectively. In the group receiving adjuvant hormone therapy, the diagnostic yields were 71.2% and 43%, respectively. While C-11-choline-PET could not differentiate well and poorly differentiated Gleason score patients, FDG-PET results were almost significant (p = 0.058). A PSA value higher than 1.9 ng/ml determines a significant increase in the diagnostic yield. Adjuvant hormonotherapy has no influence on the PET results. FDG has a better correlation with the Gleason score than C-11-choline.