(UroToday.com) Beginning with the introduction of docetaxel for metastatic castration-resistant prostate cancer (mCRPC) in 2004, there has been a dramatic and rapid proliferation of systemic therapy options in advanced prostate cancer including a number of novel hormonal therapies (including abiraterone acetate and enzalutamide), second-line chemotherapy (cabazitaxel), bone-targeting agents (radium-223) and other targeted agents (including olaparib, rucaparib, and pembrolizumab), each of which has proven survival benefits. However, despite these many treatments, mCRPC remains a fatal condition and thus, there is ongoing need and interest to develop further therapies. One of the approaches gaining the most interest is so-called “theranostics” – in prostate cancer, this approach leverages molecularly targeting cancer cells using prostate-specific membrane antigen (PSMA)-targeting radioligands. As PSMA is highly expressed in prostate cancer and mCRPC lesions, the combination of PSMA-617 with the beta-emitter lutetium allows for the targeted delivery of ß-particle radiation to PSMA-expressing cells and the surrounding microenvironment.