P-0238 - Cost effectiveness of Selective Internal Radiation Therapy (SIRT) using yttrium-90 resin microspheres for the treatment of patients with inoperable...

Date 28 June 2014
Event World GI 2014
Session Poster Session
Topics Bioethics, Legal, and Economic Issues
Colon Cancer
Rectal Cancer
Surgery and/or Radiotherapy of Cancer
Presenter Maurizio Cosimelli
Citation Annals of Oncology (2014) 25 (suppl_2): ii14-ii104. 10.1093/annonc/mdu165
Authors M. Cosimelli1, R. Golfieri2
  • 1Regina Elena National Cancer Institute, Rome/IT
  • 2Sant Orsola-Malpighi Hospital, Bologna/IT

Abstract

Introduction

Treatment options for chemotherapy-refractory metastatic colorectal cancer (mCRC) are limited. Selective internal radiation therapy (SIRT) using yttrium-90 (90Y)-labelled resin microspheres (SIR-Spheres; Sirtex, Sydney, Australia) has been shown to be a well-tolerated, effective and cost-effective treatment in patients with inoperable liver-dominant chemotherapy-refractory mCRC. The aim of this analysis was to assess the sensitivity of the cost-effectiveness of SIRT compared to best supportive care (BSC) from the perspective of the National Health Service in Italy.

Methods

Survival data from a comparative retrospective cohort study of 90Y-resin microspheres vs. BSC in chemotherapy-refractory mCRC were analysed and used in a state-transition cost-effectiveness model, using Quality Adjusted Life Years (QALYs) gained as the measure of effectiveness. The model included costs for treatment acquisition, pre-treatment work-up and delivery of microspheres, and chemotherapy. Additionally, costs of managing AEs and a cost of death were included. Utility data were taken from a recent NICE economic evaluation in mCRC. A wide range of sensitivity analyses were performed on utility, overall survival and costs. The one-way sensitivity analysis varied each parameter between its lower and upper bound and investigated the effect on the cost per QALY. The probabilistic analysis simultaneously sampled each parameter from its appropriate distribution (beta for utilities, normal for costs and multivariate normal for survival curve parameters) for 1,000 simulations and investigated the uncertainty around the cost per QALY. The scenario analysis explored alternative parametric curves for overall survival, alternative sources for utility values and alternative assumptions for the proportion of time spent in the pre- and post-progression health states.

Results

The results show an increase in overall survival for patients receiving SIRT compared to BSC by a mean of 1.15 life years (2.12 vs. 0.98 years), with a corresponding increase in quality adjusted life years (1.52 vs. 0.70). The associated costs for SIRT and BSC are €39,973 vs. €15,347, respectively. The additional costs are due to the SIRT treatment and the cost associated with extension to life. The cost per QALY is €29,850. Sensitivity analyses show that the model is robust to changes in parameters. Scenario analysis results demonstrate that the cost per QALY is not sensitive to alternative assumptions for survival curves, utilities or progression, varying only between €28,657 and €31,148. The one-way sensitivity analysis found that the parameters that had the biggest effect are those relating to the curve used to model overall survival. The probabilistic sensitivity analysis found that the probability of 90Y-resin microspheres being cost effective at a willingness-to-pay threshold of €50,000/QALY is 98%.

Conclusion

This analysis demonstrated that the use of 90Y-resin microspheres is a cost-effective option in the treatment of patients with chemotherapy-refractory liver-dominant mCRC in Italy. The results are robust to a wide range of sensitivity analyses, which ensures the predictability of the results.