Conformal Radiation Therapy in Treating Patients With Metastatic Cancer Outside the Brain

DISEASE CHARACTERISTICS: * Pathologically confirmed cancer * No active disease at the primary site as assessed by physical examination, clinical evaluation, or site-specific imaging * Measurable metastatic disease meeting the following criteria: * Four or fewer sites of extracranial lesions \< 5 cm in size * If metastatic site(s) is within the lung, the following criteria must be met: * No more than two metastases in the proximal bronchial tree area (defined as 2 cm from the trachea or mainstem bronchi) * Carbon monoxide diffusing capacity (DLCO) \> 30% predicted and forced expiratory volume 1 (FEV1) \> 1.2 L (in patients with more than one metastatic site in the lungs) * If metastatic site(s) is within 2 cm of either kidney, creatinine level must be \< 1.5 times upper limit of normal (ULN) * If metastatic site(s) is within 2 cm of the liver, bilirubin level must be \< 1.5 times ULN * Patients with metastatic disease that meets any of the following criteria are excluded: * Proposed site(s) of treatment has been previously treated with radiotherapy * Metastatic site(s) requires emergent treatment (e.g., spinal cord compression, cauda equina, airway compromise, or life-threatening end-organ dysfunction) * Disease that is untreated or previously treated and progressive in the brain * Pathologic fracture or impending pathologic fracture at the metastatic site * Metastatic site(s) of a disease histology that is known to be sensitive to low doses of…