Stereotactic Body Radiotherapy for Oligometastatic Cancer: Evidence, Patient Selection, and Clinical Decision-Making

Abstract

Background: Oligometastatic disease represents an intermediate biological state between localized cancer and widely disseminated metastases. Increasing evidence suggests that aggressive local treatment directed at limited metastatic deposits may improve disease control in selected patients. Stereotactic body radiotherapy (SBRT), which delivers highly conformal ablative radiation doses over a small number of fractions, has emerged as a key modality for metastasis-directed therapy. However, important questions remain regarding optimal patient selection, integration with systemic therapy, and the strength of existing clinical evidence. Methods: A narrative review of the current literature was performed focusing on prospective trials, randomized studies, and major clinical series evaluating SBRT in oligometastatic disease. Particular emphasis was placed on landmark trials including SABR-COMET, ORIOLE, STOMP, and studies evaluating local consolidative therapy in oligometastatic non-small cell lung cancer. Evidence relating to site-specific outcomes, treatment planning considerations, and emerging systemic therapy combinations was also examined. Results: Prospective clinical trials have demonstrated encouraging outcomes with SBRT in carefully selected patients with limited metastatic disease. Randomized phase II studies such as SABR-COMET have reported improvements in overall survival and progression-free survival when ablative radiotherapy is delivered to all metastatic sites. In oligometastatic prostate cancer, metastasis-directed therapy has been shown to delay disease progression and postpone initiation of systemic treatment. Similar benefits have been observed in selected patients with oligometastatic non-small cell lung cancer receiving local consolidative therapy after systemic treatment. Nevertheless, the available evidence remains heterogeneous, and most trials are limited by small sample sizes and varying definitions of oligometastatic disease. Conclusions: SBRT represents an important component of the evolving management of oligometastatic cancer. While early clinical trials support its use in carefully selected patients, optimal patient selection, treatment sequencing, and integration with modern systemic therapies remain active areas of investigation. Ongoing randomized trials and translational research are expected to further clarify the role of SBRT within multimodality treatment strategies for metastatic cancer.