Targeted Oligometastatic Radiation in Pediatric and Young Adult Patients With Soft Tissue and Bone Sarcoma

Stratum A Inclusion Criteria: * Patients must be aged \< 39 years at time of enrollment. * Patients must have a Karnofsky or Lansky performance score of 70 or greater or Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. * Patients must have newly diagnosed histologically or molecularly confirmed soft tissue or bone sarcoma at any site. * Patients must have metastatic disease that is measurable and this is defined as at least one lesion discontinuous from the primary that can be accurately measured in at least one dimension (longest diameter to be recorded) as \> 3mm with CT scan within 3 weeks from treatment start. Stratum B Inclusion Criteria: * Patients must have a Karnofsky or Lansky performance score of 70 or greater or ECOG performance status of 0-1. * Patients must have radiographic, histologic or molecular confirmation of progressive soft tissue or bone sarcoma at any site that was initially diagnosed at age \< 39 years. Progression includes progression at a new site or known sites of prior disease (e.g. recurrent). * Patients must have metastatic disease that is measurable and this is defined as at least one lesion discontinuous from the primary that can be accurately measured in at least one dimension (longest diameter to be recorded) as \> 3mm with CT scan * Radiation to at least one site is being recommended as part of second line therapy. Stratum A Exclusion Criteria: * Brain or intracranial metastases, including leptomeningeal disease * Clinical or radiologic evidence of spinal cord compression requiring emergent radiation treatment * Positive bone marrow biopsy for non-pelvic primary and greater than eight bone metastases. Presence of parenchymal lung metastases is considered as one metastasis, irrespective of how many lung nodules are present. * Evidence of any non-measurable metastatic disease including but not limited to leptomeningeal disease, malignant ascites and malignant pleural or pericardial effusions. * Pregnancy Stratum B Exclusion Criteria: * Brain or intracranial metastases, including leptomeningeal disease * Clinical or radiologic evidence of spinal cord compression requiring emergent radiation treatment * Evidence of any non-measurable metastatic disease including but not limited to leptomeningeal disease, malignant ascites and malignant pleural or pericardial effusions. * Pregnancy