ABSTRACT
The potential use of yttrium-90 glass microspheres in the treatment of hepatocellular carcinoma was assessed in a pilot study of seven patients. The Y-90 microspheres were injected via a hepatic artery catheter. In this group of patients, no toxicity was observed for absorbed doses of between 5,000 and 10,000 cGy to the liver and up to 32,000 cGy to the tumor itself. Tumor response was seen only at the higher absorbed doses. The new Y-90 glass microspheres can safely deliver large doses of internal radiation to hepatic tumors as long as extrahepatic shunting can be excluded. Extrahepatic shunting will be the main limitation to this form of radiation therapy.
Subject(s)
Brachytherapy/methods , Carcinoma, Hepatocellular/radiotherapy , Liver Neoplasms/radiotherapy , Yttrium Radioisotopes/therapeutic use , Dose-Response Relationship, Radiation , Glass , Hepatic Artery , Humans , Microspheres , Pilot ProjectsABSTRACT
Urgent coronary revascularization for acute myocardial ischemia results in an increased mortality and morbidity. Deposition of activated platelets and leukocytes into the ischemic myocardium during reperfusion may augment perioperative ischemic injury. Dipyridamole reduces platelet activation and may reduce myocardial deposition and prevent ischemic injury during reperfusion. The effects of dipyridamole on myocardial platelet and leukocyte deposition were evaluated in a canine model of acute regional myocardial ischemia with reperfusion during cardioplegia on cardiopulmonary bypass. Eight dogs underwent left anterior descending (LAD) coronary artery ligation for 45 min followed by cardiopulmonary bypass and release of the ligature during 60 min of cold crystalloid cardioplegic arrest to simulate urgent revascularization. Four dogs were randomized to receive an infusion of dipyridamole perioperatively (50 mg/hr) and 4 dogs served as controls. Autologous platelets were labeled with 111In, leukocytes with 99mTc, and erythrocytes with 51Cr. The labeled cells were infused immediately after cross-clamp release and myocardial biopsies were obtained at 10, 20, 30, and 60 min of reperfusion. Platelets were deposited in the myocardium during reperfusion and four times more platelets were found in the LAD region than the circumflex region. Leukocyte deposition was similar in the LAD and circumflex regions. Dipyridamole reduced both platelet and leukocyte deposition and the reduction was greater in the LAD than in the circumflex region. Myocardial platelet and leukocyte deposition was found after regional ischemia, cardioplegia, and cardiopulmonary bypass. Dipyridamole reduced myocardial platelet and leukocyte deposition and may reduce perioperative ischemic injury.
