This clinical trial studies the side effects of magnetic resonance (MR)-guided stereotactic body radiation therapy (SBRT) and to see how well it works in treating patients with solid tumors that have spread from where they first started (primary site) to other places in the body (metastatic). SBRT is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body. The total dose of radiation is divided into smaller doses given over 1-5 days. This type of radiation therapy helps spare normal tissue. During MR-guided SBRT, MR imaging is used to define and localize the area to be treated and provide more accurate delivery. This allows the treatment to be given over one day. MR-guided SBRT may be safe, tolerable, and/or effective in treating patients with metastatic solid tumors. Tumors in the central nervous system will not be treated on this study.