We describe a randomized, non-blinded Phase II interventional study to assess the safety and efficacy of stereotactic ablative radiotherapy (SABR) for hormone-sensitive oligometastatic prostate adenocarcinoma, and to describe the biology of the oligometastatic state using immunologic, cellular, molecular, and functional imaging correlates. | A phase II randomized trial of Observation versus stereotactic ablative RadiatIon for OLigometastatic prostate CancEr ORIOLE