Cost-effectiveness analysis of a randomized study with stereotactic radiosurgery (SRS) alone versus SRS plus whole brain radiation therapy (WBRT) for patients with brain metastasis

Abstract

6624 Background: This paper illustrates the incremental cost-effectiveness ratio (ICER) and cost-utility comparison of SRS alone versus SRS plus WBRT for brain metastasis. Methods: A decision analysis model, including subsequent treatment for recurrences, was developed and populated with data from patients randomized to either SRS alone (SA) versus SRS plus WBRT (SW), using costs from the healthcare institution perspective and outcomes based on actual life years saved (LYS) and quality-adjusted-life-years (QALYs). Utilities were captured through a time-trade -off methodology, utilizing three time horizons: 10 years, 5 years, and 1 year. Tornado diagrams and one-way sensitivity analyses were conducted to determine robustness of the model. Results: Fifty-eight patients were included in the final analysis, with 31 patients in the SA arm and 27 patients in the SW arm. The average cost of the SA arm is $119,000 versus $74,000 for the SW arm. The average effectiveness for the SA arm was 1.64 LYS versus 0.60 LYS for the SW arm. The ICER for total costs per LYS and QALYs were: $43,986 per LYS; $42,136 per QALY (10year); $43, 719 per QALY (5year); $44,686 (1year) for the SA arm. The surgical cost per LYS was $7,131 for the SA arm, and the radiation cost per LYS analysis was dominated. Tornado diagrams revealed that the following variables had the highest impact on the ICER: probability of being alive with SA in recursive partitioning analysis (RPA) class 2 and no recurrence; probability of no recurrence in RPA class 2 with SA; probability of being alive with SA in RPA class 2 and being treated for recurrence; probability of no recurrence in RPA class 1 with SA; and probability of being alive with no recurrence in RPA class 1 with SA. One-way sensitivity analysis exhibited a wide range variation for the first three of the above mentioned probabilities, with the final two having less variation. Conclusions: Compared to other interventions in the $50,000 to $100,000 per QALY cost-effectiveness range from an economic perspective, the application of SA, with subsequent surgical management of recurrences, is shown to be a reasonable treatment modality for brain metastasis. No significant financial relationships to disclose.