カナイ　タカユキ   KANAI Takayuki   金井　貴幸    所属   医学部 医学科（東京女子医科大学病院）    職種   講師
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Error on the stopping power ratio of ERKODENT's mouthpiece for head and neck carbon ion radiotherapy treatment.
掲載誌名	正式名：Journal of applied clinical medical physics 略　 称：J Appl Clin Med Phys ISSNコード：15269914/15269914
掲載区分	国外
巻・号・頁	24(5),pp.e13987
著者・共著者	Lee Sung Hyun, Kanai Takayuki, Souda Hikaru, Miyasaka Yuya, Chai Hongbo, Ono Takuya, Yamazawa Yoshifumi, Suzuki Koji, Sato Azusa, Katsumata Masashi, Iwai Takeo
担当区分	2nd著者
発行年月	2023/05
概要	The errors on the stopping power ratio (SPR) of mouthpiece samples from ERKODENT were evaluated. Erkoflex and Erkoloc-pro from ERKODENT and samples that combined Erkoflex and Erkoloc-pro were computed tomography (CT)-scanned using head and neck (HN) protocol at the East Japan Heavy Ion Center (EJHIC), and the values were averaged to obtain the CT number. The integral depth dose of the Bragg curve with and without these samples was measured for 292.1, 180.9, and 118.8 MeV/u of the carbon-ion pencil beam using an ionization chamber with concentric electrodes at the horizontal port of the EJHIC. The average value of the water equivalent length (WEL) of each sample was obtained from the difference between the range of the Bragg curve and the thickness of the sample. To calculate the difference between the theoretical and measured values, the theoretical CT number and SPR value of the sample were calculated using the stoichiometric calibration method. Compared with the Hounsfield unit (HU)-SPR calibration curve used at the EJHIC, the SPR error on each measured and theoretical value was calculated. The WEL value of the mouthpiece sample had an error of approximately 3.5% in the HU-SPR calibration curve. From this error, it was evaluated that for a mouthpiece with a thickness of 10 mm, a beam range error of approximately 0.4 mm can occur, and for a mouthpiece with a thickness of 30 mm, a beam range error of approximately 1 mm can occur. For a beam passing through the mouthpiece in HN treatment, it would be practical to consider a mouthpiece margin of 1 mm to avoid beam range errors if ions pass through the mouthpiece.
DOI	10.1002/acm2.13987
PMID	37018016