@misc{oai:repo.qst.go.jp:00064214,
 author = {Sato, Tatsuhiko and Watanabe, Ritsuko and Sihver, Lembit and Kase, Yuki and Tsuruoka, Chizuru and Suzuki, Masao and Furusawa, Yoshiya and 鶴岡 千鶴 and 鈴木 雅雄 and 古澤 佳也},
 month = {Nov},
 note = {The particle transport simulation codes can be categorized into microscopic and macroscopic types, which are generally used for analyzing the particle motion in the sizes smaller and bigger than a human cell, respectively. However, it is very difficult to handle both the microscopic and macroscopic simulations at once, since it is impractical to perform the microscopic track-structure simulation directly in the macroscopic codes because of computational-time limitations. We therefore developed a mathematical model for calculating the microdosimetric quantity y around the trajectory of charged particles on the basis of track-structure simulation, and implement it in the macroscopic particle transport simulation code PHITS in order to estimate the probability density of y in macroscopic matters [1].
 As an example of the application of the improved PHITS, we calculated the biological dose for charged-particle therapy for various cell lines, using the code coupled to the microdosimetric kinetic (MK) model. In the MK model, the RBE of charged particles can be determined from the probability density of y in tumor, which can be calculated by the improved PHITS within reasonable computational time. It is found from the calculation that the biological doses vary with the cell line by approximately 8%, but their depth distributions were almost independent of the cell line.
 The difference of the concept of the microscopic and macroscopic simulations will be discussed at the meeting, together with the past and future applications of the microdosimetric function implemented in PHITS.
[1] T. Sato et al, Radiat. Res. 171, 107 (2009), MC2010; An international workshop in Monte Carlo computational methods in radiation track simulation and applications in physical, biological, and medical sciences.},
 title = {Development and applications of the microdosimetric function implemented in the macroscopic particle transport simulation code PHITS},
 year = {2010}
}