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Optimization of raster scanning irradiation taken account of exposure during beam spot transition
https://repo.qst.go.jp/records/68722
https://repo.qst.go.jp/records/68722d625455a-3610-4108-b51f-182c0c74507f
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-10-17 | |||||
| タイトル | ||||||
| タイトル | Optimization of raster scanning irradiation taken account of exposure during beam spot transition | |||||
| 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 |
Inaniwa, Taku
× Inaniwa, Taku× 稲庭 拓 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | In order to make the most use of the merits of heavy-ions in a cancer treatment,at present, the raster scanning is an ieal irradiation technique at least for static tumor.Therefore,a project to construct new treatment rooms dedicated to this irradiation technique has been started at Heavy Ion Medical Accelerator in Chiba(HIMAC) since this April. In this new irradiation facility,we intend to treat not only the static tumor but also the moving tumor in cooperation with the gated irradiation(GI)and rescanning(RS)method.In our scanning scheme 'raster scanning',contrary to the strict sense of spot scanning irradiation,the beam delivery is not switched-off during the transitiontime from one spot to the next.Therefore,in this scheme,a'transition-exposure',which means the undesired dose deposition during the beam spot transition,is unavoidable.This effect can be neglected if the beam intensity is quite low e.g.10^6^particles/s and the magnetic scanning velocity is about 5-10mm/ms.However,the beam intensity as high as ~10^8^particles/s is required to shorten the treatment time,e.g.5min,and reduce the stress put on a patient due to prolonged fixation,especially in the treatment of a moving tumor with GI and RS.In this case,the transition-exposure cannot be neglected and will make a severe distortion on the dose distribution in a tumore molume.To overcome this problem, we have developed the optimization method that includes the effect of the transition-exposure in optimization calculation of spot beam distribution,and showed the effectiveness of this method with computer simulation.Our optimization caluclation is based on the limted-memory BFGS algorithm(L-BFGS).The transition-exposure depends on the magnetic scanning velocity(each x-andy-direction)and beam intensity and modeled to be deposited between two successive beam spots in our optimization calculation.With the optimized spot beam distribution,flat biological dose distribution over the target volume could be achieved through our simulation for several targets with different shapes and/or sizes. The details of our simulation results will be presented in the meeting. | |||||
| 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 | PTCOG45 | |||||
| 発表年月日 | ||||||
| 日付 | 2006-10-11 | |||||
| 日付タイプ | Issued | |||||
