This study investigates the use of an investigational medication combined with ketoconazole and hydrocortisone for treating prostate cancer. Prostate cancer is a disease where cancer cells form in the tissues of the prostate. The study aims to explore how the energy from a radioactive compound can potentially kill cancer cells, especially in cases where the cancer has returned after surgery or radiation and has not responded to initial hormonal therapy.

Participants in the study will receive a combination of investigational medication, ketoconazole, and hydrocortisone. The investigational medication is a substance being tested to see if it can help treat prostate cancer more effectively. Ketoconazole and hydrocortisone are medications that help manage hormone levels and inflammation.

• Who can participate: Men with prostate cancer confirmed by diagnosis, treated with surgery or radiotherapy, and showing biochemical progression after castration can participate. They should be at high risk of systemic progression and must not have recently used blood or platelet transfusions, growth factors, or have active infections.
• Study details: Participants will be given an investigational medication alongside other medications. A placebo is not used in this study.