The objective of the proposed study is to evaluate a molecular image directed, three-dimensional (3D) ultrasound guided biopsy system in human patients. Prior studies have shown that Positron Emission Tomography (PET)/Computed Tomography (CT) imaging with the PET molecular imaging agent, FACBC (a synthetic amino acid), is more sensitive than the FDA-approved prostate specific membrane antigen single-photon emission computed tomography (SPECT) radiotracer in prostate cancer detection. FACBC images showed higher focal uptake in tumor foci than in normal prostate and thus could be ideal information to direct targeted biopsy of the prostate. This targeted biopsy system has a unique feature that PET/CT images can be registered with 3D ultrasound images, as a result, a suspicious PET lesion is superimposed over the real-time ultrasound data; and the fused image is then used to direct biopsy needles to tumor targets.