PCN117 - Selective Internal Radiotherapy (SIRT) Using Resin Yttrium-90 Microspheres for Chemotherapy-Refractory Metastatic Colorectal Cancer: A UK Cost-Effectiveness Analysis

Abstract

Treatment options for chemotherapy-refractory liver metastases resulting from colorectal cancer are limited. The safety and efficacy of SIRT using resin yttrium-90 microspheres was studied in this population. The objective of this analysis was to assess the cost-effectiveness of SIRT compared to best supportive care (BSC) from the perspective of the UK NHS. A state-transition model was constructed, based on survival curves from a retrospective cohort study of yttrium-90 resin microspheres (SIR-Spheres; Sirtex, Sydney, Australia) vs. BSC in chemotherapy-refractory mCRC. The model included costs for treatment acquisition, pre-treatment work-up and delivery of microspheres, and chemotherapy received in addition to, instead of, or after, SIRT. In addition, costs of managing AEs and a cost of death were included. Costs were microcosted using NHS reference costs and the British National Formulary 64. Utility data were taken from a recent NICE economic evaluation in metastatic colorectal cancer. The results showed an increase in survival for patients receiving SIRT compared to BSC (2.09 vs. 0.97 years), with a corresponding increase in quality adjusted life years (1.50 vs 0.69). The associated costs were £35,487 vs.£12,730 for SIRT and BSC, respectively. The additional costs were due to the SIRT treatment and the cost associated with extension to life. The cost per QALY was £28,216 (cost per life year £20,323). The results were robust to alternative assumptions tested in scenario analyses; survival functions, utilities or the time spent pre- and post-progression. However, one-way sensitivity analysis showed results were most sensitive to the parameters for the survival functions. Data shown here were also consistent with published clinical studies. The analysis demonstrates that SIRT using resin yttrium-90 microspheres has the potential of being a cost-effective option in the treatment of patients with chemotherapy-refractory liver metastases resulting from colorectal cancer.