The clinical data on the role of 11C-acetate PET in human tumors is being accumulated. Most clinical studies have investigated the role of 11C-acetate PET in detection of prostate cancer. 11C-acetate PET was found valuable in the detection of recurrent prostate cancer, both in the prostate bed, lymph nodes and distant metastases. The main advantage of 11C-acetate is that it does not show physiological accumulation in the urinary bladder as is the case with 18F -FDG and therefore may be appropriate for the detection of active pelvic disease.