Stereotactic body radiotherapy for oligometastatic disease: current evidence and future perspectives

Oligometastatic disease (OMD) represents an intermediate state between locoregionally advanced and widespread polymetastatic disease, where local therapy may alter disease progression and improve survival. Metastasis-directed therapy (MDT), particularly stereotactic body radiotherapy (SBRT), has been evaluated alongside systemic therapy, yet OMD definitions and criteria for selecting patients who benefit from local therapy remain inconsistent. This review summarizes recent clinical trials on SBRT for OMD across cancer types. The SABR-COMET trial suggested that MDT may improve survival in OMD across various malignancies. In non-small cell lung cancer (NSCLC), phase II and some phase III trials support local therapy's effectiveness, particularly in combination with systemic treatment, though optimal patient selection remains uncertain. In breast cancer, randomized data remain inconclusive, with NRG-BR002 failing to show a survival benefit, highlighting the need for better patient stratification. In prostate cancer, multiple phase II trials suggest that MDT prolongs androgen deprivation therapy (ADT)-free survival, but no phase III trials have confirmed these findings. Emerging data indicate that MDT may also benefit OMD patients with less common primary cancers, including pancreatic and renal cell carcinoma, though further phase III trials are needed. Ongoing research aims to refine patient selection and integrate MDT into clinical practice to optimize outcomes. Standardized OMD definitions, improved biomarkers, and better stratification criteria are crucial to maximizing the benefit of MDT. The results of ongoing phase III trials will be pivotal in determining its role in oligometastatic cancer management.