The development of innovative approaches that would reduce the sensitivity of healthy tissues to irradiation while maintaining the efficacy of the treatment on the tumor is of crucial importance for the progress of the efficacy of radiotherapy. Recent methodological developments and innovations, such as scanned beams, ultra-high dose rates, and very high-energy electrons, which may be simultaneously available on new accelerators, would allow for possible radiobiological advantages of very short pulses of ultra-high dose rate (FLASH) therapy for radiation therapy to be considered. In particular, very high-energy electron (VHEE) radiotherapy, in the energy range of 100 to 250 MeV, first proposed in the 2000s, would be particularly interesting both from a ballistic and biological point of view for the establishment of this new type of irradiation technique. In this review, we examine and summarize the current knowledge on VHEE radiotherapy and provide a synthesis of the studies that have been published on various experimental and simulation works. We will also consider the potential for VHEE therapy to be translated into clinical contexts.

Triple-negative breast cancer (TNBC) cells frequently harbor defects in the homologous recombination pathway,¹ which plays a prime role in DNA double-strand breaks repair. In a context of homologous recombination deficiency, use of poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors indirectly increases the frequency of unrepaired double-strand break by affecting the base excision repair pathway after DNA-damaging stresses,² such as chemotherapy or radiotherapy. Preclinical studies have confirmed the radiosensitizing properties of PARP inhibitors in breast cancer murine models.³

Proton therapy for breast cancer treatment reduces cardiac radiation exposure. Left-sided breast cancer patients with indication for internal mammary chain (IMC) irradiation are most at risk of rad...