Yttrium-90 microspheres: Radiation therapy for unresectable liver cancer

Hepatocellular carcinoma (HCC) constitutes a difficult health challenge because of its poor prognosis and limited treatment options. Most available therapies are used only for palliation. The use of yttrium-90 microspheres is a new intraarterial therapy consisting of beta-irradiating microspheres measuring 20-30 μm in diameter that can be delivered directly to the tumors. ⁹⁰Y microspheres, which carry the radiation, are selectively taken up by the tumors, thus preserving normal liver. In several studies to date, ⁹⁰Y microspheres have proved to have a low toxicity profile and have generally been well tolerated by patients. Other than transient elevation in liver enzyme levels and mild fatigue and fever, no substantial treatment-related toxicities have been observed. Gastrointestinal toxicities occur in a limited number of cases and are preventable with proper knowledge of visceral arterial anatomy. The effect on survival is also promising, with median survival rates of 23 months (95% confidence interval = 14, 44) and 11 months (95% confidence interval = 6, 26) for patients with Okuda stage I and stage II disease, respectively. On the basis of these data, intraarterial delivery of ⁹⁰Y microspheres offers a new alternative in the treatment of unresectable HCC.