About Us


Department Department of Energy Sciences
Job title Coordinate Professor
Degree Doctor of Engineering
Room# / Phone Suzukakedai Campus G3-502, +81-45-924-5694
Affiliation / Phone National Institute of Radiological Sciences / +81-43-206-3170
E-mail matsufuji.n.aam.titech.ac.jp / matufujinirs.go.jp
Web page http://www.nirs.go.jp/index.html
Keywords Carbon ion RT, biological modeling, radiation quality, medical radiation physics

Research Highlights

Our laboratory scopes on physical and biophysical subjects related to carbon-ion and photon radiotherapy. Most of the studies are carried out at the National Institute of Radiological Sciences with HIMAC (Heavy Ion Accelerator in Chiba), the world’s first medically-dedicated heavy ion accelerator complex at where the carbon ion RT has been carried out since 1994. Some of the research activities are carried out under the collaboration with Kohno Laboratory. A part of the ongoing studies are:

  1. Radiation quality of therapeutic beams
    • In order to treat a deep-seated tumor, carbon ions are accelerated to 60 ~ 70 % of the light speed. When such high energetic ions collide with target nucleus, both are broken into fragment particles. Biological effect of such particles is considered to be dependent on the particle species; therefore, it is necessary to understand the radiation quality in good precision. From the viewpoint, we are now developing a real-time particle tracker which enables to identify a particle in the beam even by the difference of mass number and online monitoring of therapeutic beam.
    • Therapeutic X rays from latest linac is often energetic enough to cause a photo-nuclear reaction in a material. Protons and neutrons are emitted through the reaction and cause extra biological effect. These effects have been studied with developing a detector to detect the reaction.
  2. Biological effect of radiations
    • Formation of bubbles by radiations in a super-heated bubble detector is considered to be analogous with the inactivation process of cells. In order to seek the possibility to apply the detector for the estimation of biological effectiveness at the point of interest in the irradiation field, a model for the bubble formation as well as for the estimation of biological effect has been investigated.
    • Biological effect by radiations is modulated by various factors. Among them, effects by radiation quality, repair kinetics and oxic status have been investigated through in-vitro biological experiment and model analysis.