[18a-Z12-1~11] 2.5 Medical application

[18a-Z12-4] Prompt X-ray imaging of therapeutic carbon-ion beams in a human head phantom

〇Mitsutaka Yamaguchi¹, Seiichi Yamamoto², Maki Kitano², Takashi Akagi³, Yuto Nagao¹, Naoki Kawachi¹ (1.QST Takasaki, 2.Nagoya Univ. (Med.), 3.Hyogo Ion Beam Med. C)

Keywords:particle- beam cancer therapy, prompt X-ray, secondary electron bremsstrahlung

Monte Carlo simulations were performed to evaluate whether the depth of arrival of three carbon ion beams with different energies in a human head phantom can be discriminated from the measurement of prompt X-rays (secondary electron bremsstrahlung) using an X-ray camera placed around the phantom. In addition, at the Hyogo Ion Beam Medical Center, carbon ion beams incident on a human head phantom was measured by an X-ray camera from the parietal (0°) and temporal region (90°) of the head, and the results were compared with the simulation ones. The obtained trajectory shapes were in good agreement with the simulations and the experiments, and the difference in the beam-trajectory length of approximately 2 cm could be clearly identified. The simulations also showed that the beam trajectories can be visualized and the differences in the beam-trajectory length can be discriminated in a wide range of placement of the camera (0-135° and 225-360°).