Hepatic vein tumor thrombus as a risk factor for excessive pulmonary deposition of microspheres during TheraSphere therapy for unresectable hepatocellular carcinoma.

Purpose: To evaluate the impact of identifiable hepatic vein tumor thrombus on the ability to safely deliver TheraSphere (yttrium 90-containing glass microspheres) for the treatment of hepatocellular carcinoma (HCC).
Materials and Methods: A retrospective review was performed of 87 patients (71 men, 16 women; mean age, 64.5 years; age range, 25-83 y) referred for TheraSphere therapy for HCC during a 2-year period between April 2005 and May 2007. Evaluation included contrast-enhanced computed tomography or magnetic resonance imaging, selective mesenteric angiography, and radionuclide perfusion scintigraphy to measure the arteriovenous shunting through the tumor.
Results: Of the 87 patients, 83 underwent angiography and perfusion scintigraphy; 53 were ultimately treated with 65 glass microsphere infusions. Twelve of 83 were identified as having tumor thrombus in a hepatic vein or extending into the inferior vena cava. The mean lung shunt for the patients with hepatic vein tumor thrombus was 30% (range, 11%-60%), compared with 8.2% (range, 3%-23%) for patients without identifiable tumor thrombus. Two of the 12 patients were treated with reduced doses of glass microspheres, and the remaining 10 were offered alternative therapies.
Conclusions: The presence of hepatic vein tumor thrombus is a risk factor for an increased lung shunt that may prohibit delivery of a therapeutic dose of TheraSphere to hepatic tumor.