Cost-effectiveness of adding an electron-beam boost to tangential radiation therapy in patients with negative margins after conservative surgery for early-stage breast cancer

Purpose: Electron-beam boosts (EBB) are routinely added after conservative surgery and tangential radiation therapy (TRT) for early-stage breast cance r, We performed an incremental cost-utility analysis to evaluate their cost -effectiveness. Methods: A Markov model examined the impact of adding an EBB to TRT from a societal perspective. Outcomes were measured in quality-adjusted life years (QALYs), On the basis of the Lyon trial, the EBB was assumed to reduce loc al recurrences by approximately 2% at 10 years but to have no impact on sur vival. patients' utilities were used to adjust for quality of life. Given t he small absolute benefit of the EBB, baseline utilities were assumed to be the same with or without it, an assumption evaluated by Monte Carlo simula tion. Direct medical, time, and travel casts were considered. Results: Adding the EBB led to an additional cost of $2,008, an increase of 0.0065 QALYs and, therefore, an incremental cost-effectiveness ratio of ov er $300,000/QALY. In a sensitivity analysis, the ratio was moderately sensi tive to the efficacy and cost of the EBB and highly sensitive to patients' utilities for treatment without it, Even if patients do value a small risk reduction, the mean cost-effectiveness ratio estimated by the Monte Carlo s imulation remains high, at $70,859/QALY (95% confidence interval, $53,141 t o $105,182/QALY), Conclusion: On the basis of currently available data, the cost-effectivenes s ratio for the EBB is well above the commonly cited threshold for cost-eff ective care ($50,000/QALY). The EBB becomes cost-effective only if patients place an unexpectedly high value on the small absolute reduction in local recurrences achievable with it. (C) 2000 by American Society of Clinical On cology.