Helium 4He nuclei based radiotherapy

• Published in: Applied radiation and isotopes Vol. 225; p. 112068
• Main Authors: Knake, Natalia, Prokopowicz, Rafał, Gryziński, Michał A., Kocik, Janusz
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2025
• Subjects: Alpha particles; BNCT; Dosimetry; Nuclear medicine; Nuclear physics; Radiobiology; Radiotherapy; Nuclear medicine; BNCT; Radiobiology; Alpha particles; Dosimetry; Radiotherapy; Nuclear physics
• ISSN: 0969-8043; 1872-9800; 1872-9800
• DOI: 10.1016/j.apradiso.2025.112068

Due to their advantageous physical and biological properties, 4He nuclei are the subject of growing interest in medicine. Low-energy 4He nuclei (α particles) are currently used in internal radiotherapy (IR) in the form of an implant in Diffusing Alpha-Emitters Radiation Therapy (DaRT) or radiopharmaceutical in Alpha – emitters based Radiopharmaceutical Therapy (αRT) and in binary therapy such as Boron Neutron Capture Therapy (BNCT) in a form of stable compound introduced into the body as a potential source of α particles in reaction with neutrons. High energy 4He ions were not used clinically since the 1990s. However, their application in external beam radiotherapy was extensively investigated and the first patient treatment was performed after a long time in 2021. The major challenging in dosimetry and treatment planning in radiation therapy with use of α particles is in vivo dose distribution monitoring in a body to get adequate information on biological response in cancerous and healthy tissues. The α particles, and in the case of BNCT also accompanying 7Li nuclei, cannot be measured directly, therefore suitable indirectly methods for imaging their distribution and concentration in tissues are emerging. Moreover, physical dose distribution imaging system shall be related to the specified biological response to allow real therapeutic effect determining and treatment plan establishment. Therefore, radiobiological parameters for weighting absorbed dose models taking into account synergic effects of different types of radiation in therapy are emerging. In the article general overview of used currently in clinics or being subject of pre-clinical studies 4He nuclei based therapies with particular emphasis on adequate methods of therapeutical dose imaging during therapy, was performed. •Due to their properties, α particles provide high therapeutic effect.•Low energy α particles have high LET, RBE and are less dependent on hypoxia.•Low-energy 4He nuclei (α particles) are used in internal radiotherapy and in BNCT.•Using of high energy α particles in external radiotherapy is also considered.•Adequate in vivo dose imaging system is emerging in α particles therapy.