@article{oai:repo.qst.go.jp:00048244,
 author = {早乙女, 直也 and 古川, 卓司 and 原, 洋介 and 水島, 康太 and 丹正, 亮平 and 皿谷, 有一 and 白井, 敏之 and 野田, 耕司 and 早乙女 直也 and 古川 卓司 and 原 洋介 and 水島 康太 and 丹正 亮平 and 皿谷 有一 and 白井 敏之 and 野田 耕司},
 issue = {A},
 journal = {Nuclear Instruments and Methods in Physics Research Section B},
 month = {Mar},
 note = {At National Institute of Radiological Sciences (NIRS), we have been commissioning a rotating-gantry system for carbon-ion radiotherapy. This rotating gantry can transport heavy ions at 430 MeV/u to an isocenter with irradiation angles of ±180  that can rotate around the patient so that the tumor can be irradiated from any direction. A three-dimensional pencil-beam scanning irradiation system equipped with the rotating gantry enables the optimal use of physical characteristics of carbon ions to provide accurate treatment. To ensure the treatment quality using such a complex system, the calibration of the primary dose monitor, output check, range check, dose rate check, machine safety check, and some mechanical tests should be performed efficiently. For this purpose, we have developed a measurement system dedicated for quality assurance (QA) of this gantry system: the Daily QA system. The system consists of an ionization chamber system and a scintillator system. The ionization chamber system is used for the calibration of the primary dose monitor, output check, and dose rate check, and the scintillator system is used for the range check, isocenter, and gantry angle. The performance of the Daily QA system was verified by a beam test. The stability of the output was within 0.5%, and the range was within 0.5 mm. The coincidence of the coordinates between the patient-positioning system and the irradiation system was verified using the Daily QA system. Our present findings verified that the new Daily QA system for a rotating gantry is capable of verifying the irradiation system with sufficient accuracy.},
 pages = {356--360},
 title = {Design and performance of daily quality assurance system for carbon ion therapy at NIRS},
 volume = {406},
 year = {2017}
}