Comparison of therapeutic response using RECIST criteria: Y-90 SIR-Spheres and TheraSphere treatment of unresectable hepatocellular carcinoma

Objectives There are 2 commercially available devices Y-90 SIR-Spheres (Resin microsphere, SIRTex) and TheraSphere (glass microsphere, MDS Nordion) for treatment of unresectable hepatic tumors. The objective of this study was to compare the efficacy of these two devices in treatment of patients (pts) with unresectable hepatocellular carcinoma (HCC).

Methods 79 consecutive pts with unresectable HCC were treated. 26 pts (median age 68) underwent SIR-Spheres treatment, and 53 pts (median age 71) underwent TheraSphere treatment. Tc-99m MAA imaging was used to evaluate lung shunting and SPECT/CT was used for determination of the prescribed dose. The median activity of SIR-Spheres and TheraSphere delivered were 1.14 and 2.3 GBq, respectively. The response was assessed by CT and/or MRI using RECIST criteria.

Results For SIR-Spheres, 1 treatment (3.8%) had complete response (CR), 9 (34.6%) had partial response (PR), 6 (23.1%) had stable disease (SD), and 10 (38.5%) had progressive disease (PD). For TheraSphere the response rate of CR, PR, SD, and PD are 0, 16 (30.2%), 21 (39.6%), and 16 (30.2%), respectively. There was no significant response difference between pts treated with SIR-Spheres vs. pts treated with TheraSphere. 5 (19.2%) SIR-Spheres infusions only delivered 63-96% of prescribed dose due to stasis associated with macroembolization effect of the resin beads. But SD and PR were still observed in 1 and 2 infusions, respectively. All TheraSphere treatments featured completed infusions. There was no incidence of radiation hepatitis or treatment-induced liver failure for both device treatments.

Conclusions These results suggest both Y-90 SIR-Spheres and TheraSphere are useful devices in the treatment of patients with unresectable HCC. There was no significant response difference between these two devices. SIR-Spheres treatment is sometimes associated with stasis due to its macroembolization effect.