Clinical and economic impact of multiple gated acquisition scan monitoring during anthracycline therapy

Abstract

The clinical and economic impacts of monitoring cardiac function in patients given doxorubicin have yet to be determined, especially in relation to patient age, cumulative doxorubicin dose, and the relative efficacies of doxorubicin-based vs alternative regimens. We developed a decision analysis model that includes these factors to estimate the incremental survival benefit and cost-effectiveness of using multiple gated acquisition scans to measure left-ventricular ejection fraction before and during doxorubicin chemotherapy. Probability distributions for the incidences of abnormal left-ventricular ejection fraction findings and congestive heart failure were derived from a retrospective review of 227 consecutive cases at The University of Michigan Medical Center and published findings. Multiple gated acquisition-scan monitoring minimally improved the probability of 5-year survival (<1.5% in the base--case scenario). For patients who received up to 350 mg m(-2) of doxorubicin, multiple gated acquisition-scan screening had an incremental cost of $425 402 per life saved for patients between the ages of 15--39. This incremental cost markedly decreased to $138 191, for patients between the ages of 40--59, and to $86 829 for patients older than 60 years. The small gain in 5-year survival probability secondary to multiple gated acquisition scan monitoring doubled for all age groups when the average cumulative dose for doxorubicin reached 500 mg m(-2). Variations in the cure rate differences between the doxorubicin and alternative regimens had insignificant effects on the improvement in 5-year survival rates from multiple gated acquisition-scan screening. The use of multiple gated acquisition scans for pretreatment screening appears to be more cost-effective for patients who are 40 years or older, when cumulative doxorubicin dose is 350 mg m(-2) or less.

Figure 1

Decision analysis tree for evaluating the effects of MUGA scan monitoring on 5-year survival probability for patients who are treated with doxorubicin based chemotherapy.

Figure 2

Improvement in 5-year survival rates with MUGA screening in patients given doxorubicin for two cumulative dose thresholds (⩽350 and 500 mg m⁻²).

Figure 3

Cost-effectiveness estimates for MUGA scan monitoring in patients given doxorubicin dose of ⩽350 mg m⁻² ($/life saved).

Figure 4

The benefit of MUGA scan monitoring in improving 5-year survival rates, with a cumulative doxorubicin (Dox) dose of ⩽350 mg m⁻², in terms of different 5-year disease-free survival (DFS) rates for Dox vs non-Dox therapy. (A) A cost-effectiveness model was used in which the response rates for the Dox regimen was maintained at 76% and the response for the alternative non-Dox regimen was dropped in decrements of 10%. (B) A cost-effectiveness model was used in which the response rate for the Dox regimen was maintained at 46% and the response for the alternative regimen was dropped in decrements of 10%.