[15p-D311-1~14] 2.4 Medical application

[15p-D311-11] Simultaneous imaging of prompt gamma photons and prompt X-rays during irradiation of proton beams

〇Seiichi Yamamoto¹, Tomohiro Yamashita², Yusuke Kobashi², Takuya yabe³, Mitsutaka Yamaguchi³, Naoki Kawachi³, Key Kamada⁴, Akira Yoshikawa⁴, Takashi Akagi⁵, Jun Kataoka¹ (1.Waseda Univ, 2.Kobe Proton Center, 3.QST Takasaki, 4.Tohoku University, 5.Ion Beam Medical Center)

Keywords:gamma rays, X-rays, Proton beam

Although both prompt gamma photon and prompt X-ray imaging are promising methods for observing a beam shape and estimating the range of the beam from outside a subject, the images using these two methods have not been compared under realistic conditions. To clarify the imaging capability of prompt gamma photon and prompt X-ray imaging, simultaneous imaging with these methods was conducted during irradiation by proton beams at clinical dose level. After a phantom was set on the bed of a proton therapy system, proton pencil beams and patient planning beamwere irradiated to the phantom. Prompt gamma photons and prompt X-rays emitted from the phantom were simultaneously imaged by a developed gamma camera and an X-ray camera during irradiation with proton beams to the phantom. For all of the tested beams, we could obtain the beam shapes of prompt gamma photons and prompt X-rays images. The ranges could also be estimated for all the beams. Although both methods had advantages and disadvantages, we confirmed that both methods are promising for beam imaging and also for future clinical use in proton therapy.