Particle Therapy for Breast Cancer: Benefits and Challenges

Hadron therapy with protons and carbon ions is widely attracting interest as a potential competitor of conventional photon radiotherapy. Exquisite dose distribution of charged particles allows for a higher local control of the tumor and lower probability of damage to nearby healthy tissues. Heavy ions have presumed biological advantages rising from their high-linear energy transfer (LET) characteristics, including greater cell-killing effectiveness and reduced heterogeneity dependence of radiation response. Although these advantages are clear and supported by data, only 18.0% of proton and carbon ion radiotherapy (CIRT) facilities in Europe are treating breast cancers. This review summarizes the physical and radiobiological properties of charged particles, clinical use of particle beam for breast cancer, and suggested approaches to overcome technical and financial challenges.