Figure 2.

Side-effect reduction thresholds for a range of added costs of MR-IGRT The two solid cost/QALY lines demonstrate the direct relationships between added cost of MR-IGRT and side-effect reduction needed to be cost-effective. As added costs of MR-IGRT increases, more side-effect reduction is needed to justify its use. The dotted lines represent the added costs of the two fractionation schedules determined by the cost assessment. SBRT’s added cost is $1,459 per patient and conventionally fractionated radiotherapy added cost is $10,129 per patient. The points where the dotted lines intersect the solid lines represent the minimum side-effect reductions MR-IGRT need to achieve to be cost-effective. For SBRT, the thresholds are 14% using $50,000/QALY and 7% using $100,000/QALY. For conventional fractionation, the thresholds are 94% using $50,000/QALY and 50% using $100,000/QALY. MR-IGRT, MRI-guided radiotherapy; QALY, quality adjusted life year; SBRT, stereotactic body radiotherapy.