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Measurement of Variation in Water Equivalent Path Length
https://repo.qst.go.jp/records/59510
https://repo.qst.go.jp/records/5951079b93cc1-cf55-4a3d-b2bc-6e3db1a75977
Item type | 会議発表用資料 / Presentation(1) | |||||
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公開日 | 2002-12-26 | |||||
タイトル | ||||||
タイトル | Measurement of Variation in Water Equivalent Path Length | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
資源タイプ | conference object | |||||
アクセス権 | ||||||
アクセス権 | metadata only access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
著者 |
Minohara, Shinichi
× Minohara, Shinichi× Kanai, Tatsuaki× Endo, Masahiro× Katou, Hirotoshi× Miyamoto, Tadaaki× Tsujii, Hirohiko× 蓑原 伸一× 金井 達明× 遠藤 真広× 加藤 博敏× 宮本 忠昭× 辻井 博彦 |
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抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | Purpose: To propose a method for estimating uncertainties of the range calculation in particle radiotherapy associated with organ motion along with patient respiration. Methods and Materials: A set of sequential CT images every 0.2 seconds was reconstructed from continuous x ray projection data accumulated by the dynamic scanning mode in helical CT scanner. At the same time of CT data acquisition, respiratory signal of patient and on off signal of x ray on CT scanner were recorded. From these data, the timing of each CT image was related with the phase of respiration waveform. These CT images were analyzed in our treatment planning system that included the function converting from CT number to water equivalent path lengt(WEL). A set of CT images of the patient with liver cancer at upper right lobe was analyzed. The geometrical sizes of the liver and WELs from body surface to iso center were measured in each CT image. Results: WEL variations of depth from body surface to iso center were 6.2mm and 18.9mm at anterior posterior and posterior anterior direction, respectively. Liver size was changed to 35.2mm. However these variations were shown to be considerably reduced by gated irradiation. Conclusion: The proposed method using sequential CT images with respiration waveform was shown to be useful to evaluate the uncertainties of the range calculation associated with patient breathing. The variation of the depth along the beam path was presented in WEL rather than geometrical length. |
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会議概要(会議名, 開催地, 会期, 主催者等) | ||||||
内容記述タイプ | Other | |||||
内容記述 | The 3rd Korea-Japan joint meeting on medical physics | |||||
発表年月日 | ||||||
日付 | 2002-09-28 | |||||
日付タイプ | Issued |