Medical Radiology and Radiation Safety. 2026. Vol. 71. № 4

DOI:10.33266/1024-6177-2026-71-4-145-148

M.V. Yakovlev

FORMATION OF A PROTON BEAM FOR RADIATION THERAPY

Central Research Institute of Mechanical Engineering, Korolev, Russia

Contact person:  M.V. Yakovlev, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

ABSTRACT

Purpose: To develop and substantiate new techniques for forming a proton beam for radiation therapy that ensure a uniform distribution of the absorbed dose within the clinical target volume (CTV) while reducing the radiation burden on healthy tissues. Special attention is paid to methods that do not require reconfiguration of accelerator systems and are, consequently, suitable for real-time use.

Methods: The study considers two main approaches. The first is based on scanning the clinical target volume with the Bragg peak using a rotating disk made of tissue-equivalent material with an annular groove of variable depth (Patent No. 2823897) or using a combination of two absorbing filters for a “pencil” proton beam (Patent No. 2837979). The second method (Patent No. 2823905) consists of converting a monoenergetic beam into a beam of complex spectral composition by passing protons through a set of filters of varying thicknesses, fixed as segments on a rotating disk. The thickness and width of the filters are selected proportionally to the difference in proton ranges and the amplitudes of the histogram columns of the desired spectrum.

Results: Thus, the proposed techniques allow for:

‒ Scanning the CTV with the Bragg peak in depth without the need for accelerator retuning.

‒ Reproducing both uniform and complex absorbed dose distributions (by varying the groove profile and disk rotation speed).

‒ Converting a monoenergetic proton beam into a beam with an arbitrary spectral composition, reproducing the histogram of a given spectrum in terms of mean particle energy and relative quantity.

‒ Reducing the dose burden on healthy tissues compared to the passive scattering method and reducing the volume of pre-calculations.

Conclusions: The developed techniques for Bragg peak scanning and forming a complex spectral composition of the beam are effective, require no modification of accelerator systems, and can be used in real-time during radiation therapy sessions, as well as for experimental testing of treatment procedures. Their application helps improve irradiation accuracy and reduce undesirable radiation effects on surrounding healthy tissues.

Keywords:   proton beam, radiation therapy, clinical volume, absorbed dose, scanning technique, proton spectrum conversion

For citation:  Yakovlev MV. Formation of a Proton Beam for Radiation Therapy. Medical Radiology and Radiation Safety. 2026;71(4):145–148. DOI:10.33266/1024-6177-2026-71-4-145-148

References

1.Lebedeva Zh.S. Formirovaniye Doznykh Raspredeleniy v Protonnoy Onkooftal’mologii = Formation of Dose Distributions in Proton Onco-Ophthalmology. Candidate’s Thesis. Physical and Mathematical Sciences. St. Petersburg Publ., 2015, 134 p. (In Russ.).

2.Stroom J., Heijmen B. Safety Margins for Geometric Uncertainties in Radiotherapy and the ICRU-62 Report. Radiother. Oncol. 2002;64:75. 

3.Tsiklotron TS-80: Novyye Perspektivy v Oblasti Yadernoy Meditsiny = The C-80 Cyclotron: New Prospects in Nuclear Medicine. URL: https://www.atomic-energy.ru/SMI/2017/03/31/74329.

4.Shilobreyev B.A., Lazurik V.T., Yakovlev M.V. Granichnyye Effekty v Elementakh Bortovoy Apparatury Kosmicheskikh Apparatov pri Deystvii Potokov Ioniziruyushchego Izlucheniya = Boundary Effects in Elements of Onboard Equipment of Spacecraft Exposed to Ionizing Radiation Fluxes. Moscow, Fizmatlit Publ., 2017. 152 p. (In Russ.). ISBN 978-5-9221-1755-5.

5.Yakovlev M.V., Yakovleva A.D. Sposob Opredeleniya Kharakteristik Poley Ioniziruyushchego Izlucheniya = Method for Determining Characteristics of Ionizing Radiation Fields. Patent No.2823897. Bulletin No.22. Published July 30, 2024 (In Russ.).

6.Yakovlev M.V. Ustroystvo dlya Kontrolya Raspredeleniya Pogloshchennoy Dozy Ioniziruyushchego Izlucheniya = Device for Monitoring the Distribution of the Absorbed Dose of Ionizing Radiation. Patent No.2837979: Bulletin No.10. Published April 7, 2025 (In Russ.).

7.Yakovlev M.V., Yakovleva A.D. Sposob Opredeleniya Pogloshchennoy Dozy v Tonkikh Sloyakh Veshchestva pri Obluchenii Elektronami s Energiyey 0,1–10,0 MeV = Method for Determining the Absorbed Dose in thin Layers of Matter when Irradiated with Electrons with an Energy of 0.1–10.0 MeV. Patent No.2823905. Bulletin No.22. Published July 30, 2024 (In Russ.).

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Conflict of interest.The authors declare no conflict of interest.

Financing.  The study had no sponsorship.

Contribution. The article was prepared by one author.

Article received: 20.03.2026. Accepted for publication: 25.04.2026.