PATIENTS suffering from inoperable cancer of the liver usually die within an average of six months after diagnosis.1 This is particularly true of cancer metastatic to the liver, regardless of the type of therapy. Some beneficial results have been obtained by the surgical excision of the metastases in the liver. However, the overall results leave much to be desired, and 21 of 28 patients so treated have ultimately died from their cancers.2
The liver tolerates large doses of external irradiation, and such therapy sometimes can be beneficial in those patients with localized metastases. Unfortunately, metastases to the liver generally constitute a focus for the intrahepatic dissemination of additional metastases within the liver; consequently the liver is often studded with numerous metastatic deposits, making it impossible to deliver a cancerocidal dose of irradiation to the entire organ.
Metastases usually reach the liver via the portal system; less frequently via