Nivolumab With or Without Stereotactic Radiosurgery in Treating Patients With Recurrent, Advanced, or Metastatic Chordoma

This phase I trial studies the side effects of nivolumab with or without stereotactic radiosurgery (SRS) in treating patients with chordoma that has come back or spread from where it started to other places in the body. Monoclonal antibodies, such as nivolumab, may interfere with the ability of tumor cells to grow and spread. Stereotactic radiosurgery is a specialized radiation therapy that delivers a single, high dose of radiation directly to the tumor and may cause less damage to normal tissue. It is not yet known whether giving nivolumab with or without stereotactic radiosurgery may work better in treating patients with chordoma.