Scott T. Tagawa, MD, FACP: PSMA [prostate-specific membrane antigen]-targeted radionuclide therapy means directing a radionuclide, which is either generally a beta or alpha emitter. People are familiar with alpha emitters, as in the approved radium-223, and may remember some beta emitters. Certainly, everyone’s familiar with iodine-131 for thyroid cancer. But in the older days, we used strontium and samarium to palliate painful bone metastasis. Lutetium-177 is an approved agent targeting somatostatin for GI [gastrointestinal] neuroendocrine tumors, and is one of the leading agents in a number of tumor types, including prostate cancer. We can target or aim these radionuclides against PSMA using either small molecules or antibodies. I’m not going to go into great details about these other than to say that they have different properties and kinetics. Both are given intravenously or systemically and wind up in the tumor. The small molecules wind up in some other PSMA-positive areas, and I do think that’s important to know in terms of the toxicity or adverse event profile.