[13p-N206-1~6] 2.4 Medical application

[13p-N206-4] Experimental verification of numerical estimation of water equivalent thickness through the spectroscopy of secondary-electron bremsstrahlung for the trajectory of therapeutic particle beams

〇(M2)Ryota Satori¹, Mitsutaka Yamaguchi², Seiichi Yamamoto³, Makoto Sakai¹, Yuto Nagao², Naoki Kawachi², Wataru Kada¹, Tomihiro Kamiya¹ (1.Gunma Univ., 2.QST Takasaki, 3.Nagoya Univ.(Med.))

Keywords:particle-beam therapy, secondary-electron bremsstrahlung, attenuation correction

To establish an imaging method of therapeutic particle beam trajectories by measuring secondary-electron bremsstrahlung, an experimental verification of numerical estimation of water equivalent thickness was demonstrated. An acrylic target was irradiated with carbon beams, and the energy spectra of the secondary-electron bremsstrahlung emitted from the beam trajectories in the target were analyzed. As the thickness of the target side was increased, the number of counts decreased in the low energy region on the other hand did not change in the high energy region. This trend indicates that it is possible to estimate the water equivalent thickness from the spectrum shape.