Stereotactic Body Radiotherapy for Oligometastases: An Opportunity for Cure?

Advances in radiation oncology have enabled the delivery of ablative doses of radiotherapy (RT) to a variety of anatomic sites with increased precision and minimal toxicity. Stereotactic body radiotherapy (SBRT) has emerged as an attractive alternative to surgical resection. In this review, we will discuss the following: the proposed state of limited metastatic disease (commonly referred to as oligometastases) and the growing role of SBRT in the management of these patients; potential challenges in selecting patients with limited metastases who are most likely to benefit from aggressive local interventions; some of the key nonrandomized studies that have demonstrated the feasibility and safety of SBRT to treat multiple metastatic sites; important questions including the safety of SBRT in combination with systemic therapies; and the existing randomized data to support treatment of limited metastases and the multiple ongoing randomized trials. Lastly, we will examine the interaction between SBRT and the immune system, and explore future applications that include combining SBRT with immunotherapy.