Cost Effectiveness of External Beam Radiation Therapy versus Percutaneous Image-Guided Cryoablation for Palliation of Uncomplicated Bone Metastases.

PURPOSE

To evaluate the cost effectiveness of incorporating cryoablation in the treatment regimens for uncomplicated bone metastases using radiation therapy (RT) in single-fraction RT (SFRT) or multiple-fraction RT (MFRT) regimens.

MATERIALS AND METHODS

A Markov model was constructed using 1-month cycles over a lifetime horizon to compare the cost effectiveness of multiple strategies, including RT followed by RT (RT-RT) for recurrent pain, RT followed by cryoablation (RT-ablation), and cryoablation followed by RT (ablation-RT). RT-RT consisted of 8 Gy in 1 fraction/8 Gy in 1 fraction (SFRT-SFRT) and 30 Gy in 10 fractions/20 Gy in 5 fractions (MFRT-MFRT). Probabilities and utilities were extracted from a search of the medical literature. Costs were calculated from a payer perspective using 2017 Medicare reimbursement in an outpatient setting. Incremental cost effectiveness ratios (ICERs) were calculated using strategies evaluated for willingness-to-pay threshold of $100,000 per quality-adjusted life-year (QALY). To account for model uncertainty, one-way and probabilistic sensitivity analyses were performed.

RESULTS

In the base case analysis, SFRT-ablation was cost effective relative to SFRT-SFRT at $96,387/QALY. MFRT-ablation was cost effective relative to MFRT-MFRT at $85,576/QALY. Ablation-SFRT and ablation-MFRT were not cost effective with ICERs >$100,000/QALY. In one-way sensitivity analyses, results were highly sensitive to variation in multiple model parameters, including median survival (base: 9 months), with SFRT-SFRT favored at median survival ≤8.7 months. Probabilistic sensitivity analysis examining SFRT-based regimens showed that SFRT-ablation was preferred in 36.9% of simulations at WTP of $100,000/QALY.

CONCLUSIONS

Cryoablation is a potentially cost-effective alternative to reirradiation with RT for recurrent of pain following RT; however, no strategy incorporating initial cryoablation was cost effective.