HCC Radioembolization with Yttrium-90 Glass Microspheres (TheraSphere)

Abstract

Intraarterial radioembolization (RE) using microspheres labelled with the high-energy beta-emitter yttrium-90 (90Y) is an innovative local therapy for hepatocellular carcinoma (HCC). This procedure allows the tumour to be irradiated with a dose higher than that allowed by whole-liver external beam radiation treatment. The TheraSphere (TheraSphere_BTG®) consist of glass microspheres labelled with 90Y as an integral component of glass. The mean diameter of glass sphere is 20–30 μm, and a high specific activity per sphere at calibration is 2500 Bq. The recommended TheraSphere® Dose to the hepatic lobe is 120 Gy (80–150 Gy). It is possible to choose 35 dose size options, between 3 GBq and 20 GBq in 0.5 GBq increments, a dosing flexibility and an individualized patient treatment. Yttrium-90 glass microspheres are indicated for the treatment in early-stage HCC to the downstaging or bridging to liver transplantation or in patients with intermediate to advanced HCC. BCLC B patients refractory to transarterial chemoembolization (TACE) or BCLC C patients with branch portal vein thrombosis (PVT). Considering the favourable tumour response and long-term outcomes, this treatment is an option for unresectable HCC.