Prostate-specific membrane antigen in prostate cancer imaging and treatment

Despite the prevalence of prostate cancer (PC), conventional imaging such as computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy have significant limitations in identifying the disease, leading to problems with diagnosis and management. Prostate-specific membrane antigen (PSMA) is a membrane-bound protein that is heavily expressed on PC cells. Radiolabeled antibodies and small molecule inhibitors of PSMA have allowed for imaging with positron emission tomography (PET). These novel PET agents have been studied in a variety of clinical scenarios. Compared to conventional imaging, they are better able to detect localized disease and regional lymph nodes, reveal disease at the time of biochemical recurrence, and identify oligometastatic sites for targeted radiation therapy. While PSMA-PET appears superior to conventional imaging, it also has limitations with sensitivity in certain settings. Additionally, current reports on PSMA-PET imaging in PC are largely retrospective reviews. Well-designed prospective clinical trials should be conducted in order to understand the true potential of this novel imaging modality.