Cost-effectiveness of proton therapy compared with photon therapy for breast cancer in women in Belgium

Proton therapy reduces radiation exposure to the heart, lungs, and controlateral breast compared with conventional photon-based radiotherapy for breast cancer. However, its clinical benefit – particularly relative to photon deep inspiration breath-hold (DIBH) remains uncertain, and its high cost raises questions about cost-effectiveness. In an economic evaluation using a state-transition microsimulation analysis with 1 million patients in Belgium, proton therapy was not cost-effective (willingness-to-pay threshold EUR 45,000 per QALY) compared with photon therapy under base case assumptions. In the most favorable cost scenarion, it was cost-effective for only 3.6% of patients when compared with free breathing, and was not cost-effective for any patients when compared with DIBH. The authors conclude that these findings suggest that under current cost conditions, proton therapy appears unlikely to be cost-effective for most patients with breast cancer, particularly when DIBH is an option.