Very high-energy electrons as radiotherapy opportunity

• Published in: European physical journal plus 2024-08, Vol.139 (8), p.728, Article 728
• Main Authors: Fischer, Jade, Whitmore, Lucy, Desrosiers, Colleen, Sheehy, Suzie, Bazalova-Carter, Magdalena
• Format: Article
• Language: English
• Subjects: Applied and Technical Physics; Atomic; Atoms & subatomic particles; Complex Systems; Condensed Matter Physics; Drug overdose; Electron beams; Electrons; Energy; Focus Point on Advances in Radiation Therapy; High energy electrons; Mathematical and Computational Physics; Molecular; Optical and Plasma Physics; Patients; Pencil beams; Photon beams; Physics; Physics and Astronomy; Radiation dosage; Radiation therapy; Review; Theoretical; Tumors; X-rays
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-024-05455-x

The use of very high-energy electrons (VHEEs) with energies in the range of 100-250 MeV has recently garnered significant attention for use in radiotherapy. VHEE beams manifest distinctive dosimetric characteristics, including increased depth penetration, narrow penumbra, and insensitivity to inhomogeneities compared to clinically used 6-20 MeV electrons. These attributes increase the applicability of electron therapy to include deep-seated tumors with dose distributions similar to state-of-the-art photon beam therapy. The advantages of VHEEs are amplified by their potential use in ultrahigh dose rate (UHDR) regimes which may lead to increased tissue sparing through the FLASH effect and the potential application of pencil beam scanning technology for ultrafast conformal dose delivery. As the use of VHEEs nears clinical implementation, the aim of this review is to encapsulate the current knowledge of VHEEs, including the description of accelerator technology, dose calculations and measurements, and treatment planning and determine areas of interest for future work. Through a comprehensive analysis of these topics, this review covers exciting potential of VHEEs in modern radiotherapy practice. Additionally, a discussion of special methods of beam delivery, focused VHEEs and spatially fractionated radiotherapy, is also included to further evaluate tissue sparing potential beyond the use of UHDR radiotherapy.