Theranostics in Metastatic Castrate Resistant Prostate Cancer

Despite advances in the treatment of localized prostate cancer, many patients progress to metastatic castration-resistant prostate cancer with limited median survival benefits, and significant morbidity. Therefore, efforts to explore new therapeutic modalities for metastatic castration-resistant prostate cancer are urgently needed. A theranostic approach in oncology is based on the principle of imaging a particular molecular target with a diagnostic radioisotope, and then substituting it with a therapeutic isotope to treat a patient who demonstrates sufficient target expression on diagnostic images. Radioisotope pairs are usually chosen in such a way that their physical and chemical properties are similar to ensure the therapeutic agent will be distributed in the same way as the diagnostic agent. This chapter outlines the most recent advances in the use of prostate specific membrane antigen (PSMA) in theranostics with emphasis on Lu-PSMA, Ac-PSMA and Ra-dicloride. The clinical utility of these radioisotopes along with their limitations and future perspectives are discussed.