DISEASE CHARACTERISTICS: Diagnosis of unresectable malignant primary or metastatic liver tumors Tumors are deemed unresectable based on the following factors: 1-10 liver tumors Bilobar liver tumors Location of 1 or more lesions near a major intrahepatic vascular structure (hepatic vein, portal vein, vena cava) Severe cirrhosis to preclude a major liver resection No unresectable extrahepatic disease Prior failure of other therapeutic modalities allowed No more than moderate ascites No hepatic encephalopathy