ORLANDOTreatment of unre-sectable hepatocellular carcinoma (HCC) with 90-yttrium-embedded glass micro-spheres (TheraSphere, MDS Nordion) appears to be safe, effective, and less toxic than the alternative, transarterial che-moembolization (TACE).
The treatment delivers insoluble glass microspheres (22,000 to 73,000/mg) through a catheter to the hepatic artery via the femoral artery. Because of their small size (20 to 30 microns), they become trapped in the hepatic capillaries and exert a local radiotherapeutic effect, said Riad Salem, MD, William Beaumont Hospital, Royal Oaks, Michigan.
The first- and second-line options for unresectable HCC patients are few, Dr. Salem said at a poster session of the 38th Annual Meeting of the American Society of Clinical Oncology (abstract 553). Most are cirrhosis patients, with few qualifying for liver transplantation.
Dr. Salem presented data on a series of 36 patients selected for a planned maximum of two treatments per liver lobe under a compassionate use protocol. Pretreatment MAA (macroaggregated albumin) scans and hepatic artery angiograms were performed to rule out excessive shunting to lungs or aberrant vasculature to the intestine or stomach.
Among the 36 patients, 26 were male, with an age range between 29 and 86 years. Cirrhosis was present in 25 and hepatitis C antibody in 16. Tumors were unilobar in 27 (1.4 to 16 cm).
Hepatic lobes were treated sequentially, not less than 60 days apart. Each Thera-Sphere treatment was designed to deliver 125 to 150 Gy/kg to the liver. The beta radiation penetrates 2.5 to 3 mm, and has a half-life of 64.2 hours. "Most of the activity has dissipated after about 12 days," Dr. Salem noted.
Treatment was typically administered on an outpatient basis. Earlier experience had shown that trying to treat both lobes at once through the hepatic artery could lead to gastritis because of spherules traveling to the small bowel or stomach through small arteries. "We show that toxicities are much less when treatment is localized to the parenchyma, two treatments rather than one," Dr. Salem said.