Metastasis-directed radiotherapy (MDRT) for men with de novo, oligometastatic prostate cancer treated with long-term androgen deprivation therapy in the STAMPEDE trial (METANOVA): protocol for a multicentre, phase II randomised controlled trial in the USA

Introduction: Prostate cancer (PCa) is the most commonly diagnosed cancer in men worldwide. A rising proportion of men present with de novo metastatic disease, a state associated with poor survival outcomes and limited curative treatment options. Within this group, a subset of patients exhibit oligometastatic disease, defined by a limited number of metastases, which may represent a distinct clinical entity with potential for long-term disease control. Emerging evidence suggests that metastasis-directed radiotherapy (MDRT), including stereotactic body radiation therapy (SBRT), may improve progression-free survival in this population. However, current evidence is largely limited to phase II trials in the metachronous setting and retrospective studies in the synchronous setting. Furthermore, predictive biomarkers of treatment response in these patients remain undefined. We aim to evaluate, within a large randomised multicentre phase II trial, the efficacy and biological impact of MDRT in men with de novo oligometastatic PCa.