RecruitingPhase 2Radiation therapyUsing FAPI PET/MRI to Evaluate Prostate CancerThe goal of this clinical trial is to gain more information about how FAPI (fibroblast activation protein inhibitor) binds to certain type of cells in the tumor tissue. The main question it aims to answer is how this information can be used to better diagnose and track prostate cancer. Participants will undergo two PET/MRI scans during two research visits, each of which may last up to 2.5 hours.