Cost-effectiveness of using protons in breast cancer patients aiming at reducing cardiotoxicity: A risk-stratification analysis

Purpose Incidental exposure of heart to ionizing irradiation is associated with an increased risk of ischemic heart disease (IHD) in breast cancer patients after radiotherapy. Intensity-modulated proton radiation therapy (IMPT) offers a promise in limiting the mean heart dose (MHD) in breast irradiation to a negligible level. However, the uncertainty in cost-effectiveness hinders its use. This cost-effectiveness analysis aims to identify patients in appropriate risk groups as targets for IMPT. Methods A Markov decision model was designed to evaluate the cost-effectiveness of IMPT versus intensity-modulated photon-radiation therapy (IMRT) in reducing the irradiation-related IHD risk. Baseline evaluation was performed on 50-year-old women patient without preexisting cardiac risk factor (CRF). Stratified for preexisting cardiac risk and photon MHD, cost-effective scenarios under different proton cost and willingness-to-pay (WTP) were identified for 40-, 50- and 60-year-old patients. Results With baseline set-ups, incremental effectiveness (IE) ranged from 0.025 quality-adjusted life-year (QALY) to 0.135 QALY when photon MHD varied from 3 to 16 Gy; IE increased from 0.043 QALY to 0.964 QALY when preexisting cardiac risk increased from the baseline level to its 10 times. IMPT was not cost-effective to patients without preexisting CRF. At the WTP of China, once proton cost reduced to $20,000, IMPT would be cost-effective to ≤ 50-year-old women patients having preexisting cardiac risk of general-population level. Conclusion Patient’s preexisting cardiac risk level should be a main consideration for the clinical decision of using protons; protons may become cost-effective to general-level patients if a substantial decrease in proton cost occurs in the future.