Alpha-Emitting Radionuclide or Beta-Emitting Radionuclide With Metastasis-Directed Stereotactic Body Radiotherapy for the Treatment of Recurrent, Oligometastatic Prostate Adenocarcinoma

This phase II trial compares the use of 225Ac-PSMA-617 to 177Lu-PSMA-617, along with stereotactic body radiotherapy for the treatment of prostate cancer that has come back after a period of improvement (recurrent) and that has spread from where it first started (primary site) to multiple other places in the body (oligometastatic). 225Ac-PSMA-617 and 177Lu-PSMA-617 are radioactive drugs. They bind to a protein called a PSMA receptor, which is found on some prostate tumor cells. 225Ac-PSMA-617 or 177Lu-PSMA-617 builds up in these cells and gives off either alpha or beta radiation that may kill them. It is a type of radioconjugate and a type of PSMA analog. Stereotactic body radiation therapy (SBRT) is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body (except the brain). The total dose of radiation is divided into smaller doses given over several days. This type of radiation therapy helps spare normal tissue. Giving 225Ac-PSMA-617 or 177Lu-PSMA-617 and metastasis directed stereotactic body radiotherapy may be effective in treating patients with recurrent, oligometastatic prostate cancer.