Radiation Therapy in Metastatic Soft Tissue Sarcoma: From Palliation to Ablation

SIMPLE SUMMARY: In the United States, over 13,000 patients are diagnosed with soft tissue sarcoma annually leading to over 5000 deaths per year despite aggressive treatments including radiotherapy, surgery, and chemotherapy. Although the majority of patients present with localized disease, unfortunately many will develop metastatic disease, which is generally not curable. There is growing evidence that local ablative therapies may be beneficial in patients with a variety of metastatic malignancies. In this review article, we explore the evolving role of radiotherapy in patients with metastatic soft tissue sarcoma. In particular, we review the growing role of ablative radiotherapy for oligometastatic disease, local control of the primary site, and palliation. ABSTRACT: The management of patients with metastatic cancer is rapidly changing. Historically, radiotherapy was utilized for the treatment of localized disease or for palliation. While systemic therapy remains the mainstay of management for patients with metastatic cancer, radiotherapy is becoming increasingly important not only to palliate symptoms, but also to ablate oligometastatic or oligoprogressive disease and improve local control in the primary site. There is emerging evidence in multiple solid malignancies that patients with low volume metastatic disease that undergo local ablative therapy to metastatic sites may have improved progression free survival and potentially overall survival. In addition, there is increasing evidence that select patients with metastatic disease may benefit from aggressive treatment of the primary site. Patients with metastatic soft tissue sarcoma have a poor overall prognosis. However, there may be opportunities in patients with low volume metastatic soft tissue sarcoma to improve outcomes with local therapy including surgery, ablation, embolization, and radiation therapy. Stereotactic body radiation therapy (SBRT) offers a safe, convenient, precise, and non-invasive option for ablation of sites of metastases. In this review article, we explore the limited yet evolving role of radiotherapy to metastatic and primary sites for local control and palliation, particularly in the oligometastatic setting.