Theranostics in Prostate Cancer.

Metastatic castration resistant prostate cancer (mCRPC) is a highly mortal disease, requiring safe and effective therapeutic agents to improve the patient outcome. Prostate-specific membrane antigen (PSMA) is over expressed in many prostate cancer cells, and act as target for molecular imaging (MI) and radionuclide therapy (RNT). The introduction of Gallium-68 (68Ga) PSMA- PET/CT in 2012 has changed the management of prostate cancer. In addition to its importance in identifying PSMA expression for selection of patients suitable for PSMA RNT, PSMA- PET/CT showed superior diagnostic accuracy to combined CT and bone scan. Lutetium-177 (177Lu) PSMA-617 is the most investigated PSMA radio ligand for RNT in prostatecancer, it is a radiolabelled small molecule, binds with high affinity to PSMA, enabling beta-particles emissions with short tissue penetration depth (mean range of 0.7 mm and maximum range of 2.1 mm in soft tissue). Since 2014 multiple studies showed a highly impressive therapeutic efficacy and safety of 177Lu-PSMA RNT. The evidence achieved by these studies paved the way to ongoing randomized clinical trials, and currently this therapy is being applied and clinically accepted in many centers worldwide. The aim of this article is to share the practical aspect of PSMA Theranostics for prostate cancer, including patient selection, therapy protocol and follow-up.