Radiation Therapy in Treating Patients With Liver Metastases

DISEASE CHARACTERISTICS: * Diagnosis of 1 of the following: * Histologically confirmed non-lymphoma liver metastases * New radiographic liver lesions most consistent with metastases in a patient with known, histologically proven non-lymphoma cancer AND a previously negative CT scan, MRI, or PET/CT scan of the liver * No more than 5 measurable lesions by contrast-enhanced liver CT scan, MRI, or PET/CT scan * Liver metastases ≤ 8 cm * Medically unfit for surgery OR lesions are surgically unresectable * All intrahepatic disease must be encompassed within the study radiation field * Extrahepatic disease outside the liver is allowed provided the hepatic disease is life-limiting * At least 1,000 cc of normal liver * No clinical ascites * No CNS metastases PATIENT CHARACTERISTICS: Performance status * Zubrod 0-1 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count ≥ 1,800/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 8 g/dL (transfusion allowed) Hepatic * No active hepatitis * No clinically significant liver failure * No underlying cirrhosis Renal * Not specified Cardiovascular * No congestive heart failure requiring hospitalization within the past 6 months * No unstable angina pectoris requiring hospitalization within the past 6 months * No transmural myocardial infarction within the past 6 months Pulmonary * No chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other malignancy within the past 3 years except non-melanomatous skin cancer or carcinoma in situ of the breast, oral cavity, cervix or primary liver metastasis * No acute bacterial or fungal infection requiring IV antibiotics PRIOR CONCURRENT THERAPY: Chemotherapy * At least 4 weeks since prior chemotherapy * No concurrent chemotherapy * No anthracyclines within 4 weeks after completion of study therapy (1 week for other chemotherapy) Radiotherapy * No prior radiotherapy to the region of study * No concurrent intensity-modulated radiotherapy Surgery * Prior liver resection or ablative therapy allowed Other * No concurrent warfarin or IV heparin