Stereotactic Body Radiation Therapy in Treating Patients With Metastatic Breast Cancer, Non-small Cell Lung Cancer, or Prostate Cancer

Inclusion Criteria: * Metastatic breast cancer (MBC) OR metastatic non-small cell lung cancer (NSCLC) OR metastatic adenocarcinoma of the prostate; the sites of allowed metastases are: peripheral lung, central lung, mediastinal/cervical lymph node, liver, spinal/paraspinal, osseous, and abdominal-pelvic * NOTE: after the required number of evaluable patients have been accrued for a given dose level, the accrual for that metastatic location will be temporarily suspended while the safety of that dose level is assessed; a patient can only be entered onto the trial if all of their metastatic locations are open to accrual (e.g. if central lung is temporarily suspended for safety assessment and the patient has a central lung metastases, regardless of other metastases, they cannot enroll until the safety of dose to central lung is determined) * Primary tumor site without progression at registration * All metastases not resected must be amenable to SBRT * The patient must meet ONE of the three following criteria: * 3-4 radiographically distinct metastases of any distribution in the allowed anatomical sites OR * 2 radiographically distinct metastases that must be anatomically close (i.e., with less than or equal to 5 cm of normal tissue between them) OR * 3 or 4 distinct metastasis, 2 or 3 to be treated with SBRT and the other (s) having been surgically removed * Evaluation by a radiation oncologist within 45 days prior to study registration * Evaluation by a medical oncolo…