PSMA PET/CT is a new type of PET/CT scan that measures prostate specific membrane antigen (PSMA). It is used to locate cancerous lesions and approved for both initial staging of recently diagnosed prostate cancer, as well as the evaluation of possible local recurrence or metastatic disease in patients with previous treatment. The radioactive tracer is injected and attaches to PSMA proteins. The PSMA PET scan is a test that can help your doctor learn if and where prostate cancer has spread outside your prostate gland, including to your lymph nodes, other organs, or bones.