Applications of the microdosimetric function implemented in the macroscopic particle transport simulation code PHITS
Journal article, 2012

Purpose: Microdosimetric quantities such as lineal energy are generally considered to be better indices than linear energy transfer (LET) for expressing the relative biological effectiveness (RBE) of high charge and energy particles. To calculate their probability densities (PD) in macroscopic matter, it is necessary to integrate microdosimetric tools such as track-structure simulation codes with macroscopic particle transport simulation codes.
Methods: As an integration approach, the mathematical model for calculating the PD of microdosimetric quantities developed based on track-structure simulations was incorporated into the macroscopic particle transport simulation code PHITS (Particle and Heavy Ion Transport code System). The improved PHITS enables the PD in macroscopic matter to be calculated within a reasonable computation time, while taking their stochastic nature into account.
Applications: The microdosimetric function of PHITS was applied to biological dose estimation for charged-particle therapy and risk estimation for astronauts. The former application was performed in combination with the microdosimetric kinetic model, while the latter employed the radiation quality factor expressed as a function of lineal energy.
Conclusion: Owing to the unique features of the microdosimetric function, the improved PHITS has the potential to establish more sophisticated systems for radiological protection in space as well as for the treatment planning of charged-particle therapy.

LET

Radiotherapy

Microdosimetry

Radiation protection

RBE

Radiation physics

Author

Tatsuhiko Sato

Japan Atomic Energy Agency

Ritsuko Watanabe

Japan Atomic Energy Agency

Lembit Sihver

Subatomic, High Energy and Plasma Physics

Koji Niita

Research Organization for Information Science and Technology

International Journal of Radiation Biology

0955-3002 (ISSN) 13623095 (eISSN)

Vol. 88 1-2 143-150

Subject Categories

Subatomic Physics

Ecology

Radiology, Nuclear Medicine and Medical Imaging

DOI

10.3109/09553002.2011.611216

More information

Latest update

10/24/2022