In the modern era, what is the role of beta-emitting bone-targeted radiopharmaceutical therapy?

Since the approval of Radium-223 dichloride (Xofigo), I have been using it as the preferred radiopharmaceutical for patients with mCRPC. While use of Samarium-153 and Strontium-89 improves pain control, Radium-223 is an alpha-emitter and is the only FDA approved radiopharmaceutical that has been sho...