国际生物医学工程杂志
國際生物醫學工程雜誌
국제생물의학공정잡지
International Journal of Biomedical Engineering
2015年
4期
214-217,后插6
,共5页
郭妍妍%蒋胜鹏%戴越%毕平%李小东
郭妍妍%蔣勝鵬%戴越%畢平%李小東
곽연연%장성붕%대월%필평%리소동
治疗计划系统%治疗床%精确性%衰减
治療計劃繫統%治療床%精確性%衰減
치료계화계통%치료상%정학성%쇠감
Treatment planning system%Treatment table%Accuracy%Attenuation
目的 研究医科达PRECISE加速器C型臂型治疗床及体位固定装置对治疗计划射野剂量传递精确性的影响,并探索一种消除该影响的方法.方法 将固体水和电离室进行CT扫描并将扫描图像传到治疗计划系统(TPS)中.在TPS中设置照射参数:选用6 MV的X射线、100 MU机器跳数,射野大小分别为5 cm×5 cm和10 cm×l0 cm,从机架角0°开始,在0°～180°区间内每隔5°为间隔定义射野入射方向进行等中心照射.按照TPS中设置的条件分别测量带有及无治疗床C型臂和体位固定装置时的绝对剂量,将测量结果进行记录并分析.在MatriXX二维电离室矩阵系统上执行同样的照射野计划,使用OmniPro I'mRT软件中"add constant value"功能,找出最合适的增加总剂量的系数因子.选取6例盆腔肿瘤患者剂量增加前后的调强放疗计划验证该因子能否消除治疗床及体位固定装置对治疗计划射野剂量的衰减.结果 放射治疗中加速器治疗床及体位固定装置对后斜野照射剂量衰减有一定的影响,在65°～70°和1 15°～125°两个入射范围对剂量的影响最大.根据实验分析结果,将计划的总剂量等比例向上归一,将总剂量增加2％,可弥补治疗床和体位固定装置对放疗剂量的衰减,提高总的射野通过率.结论 在设计治疗计划中照射野的入射方向时,应尽量使机架角度避开65°～70°和115°～125°及对侧的290°～295°和230°～245°两个入射范围.由于治疗床和体位固定装置对后斜野照射剂量衰减有影响,因此应在TPS中针对剂量衰减值进行相应的剂量补偿.
目的 研究醫科達PRECISE加速器C型臂型治療床及體位固定裝置對治療計劃射野劑量傳遞精確性的影響,併探索一種消除該影響的方法.方法 將固體水和電離室進行CT掃描併將掃描圖像傳到治療計劃繫統(TPS)中.在TPS中設置照射參數:選用6 MV的X射線、100 MU機器跳數,射野大小分彆為5 cm×5 cm和10 cm×l0 cm,從機架角0°開始,在0°～180°區間內每隔5°為間隔定義射野入射方嚮進行等中心照射.按照TPS中設置的條件分彆測量帶有及無治療床C型臂和體位固定裝置時的絕對劑量,將測量結果進行記錄併分析.在MatriXX二維電離室矩陣繫統上執行同樣的照射野計劃,使用OmniPro I'mRT軟件中"add constant value"功能,找齣最閤適的增加總劑量的繫數因子.選取6例盆腔腫瘤患者劑量增加前後的調彊放療計劃驗證該因子能否消除治療床及體位固定裝置對治療計劃射野劑量的衰減.結果 放射治療中加速器治療床及體位固定裝置對後斜野照射劑量衰減有一定的影響,在65°～70°和1 15°～125°兩箇入射範圍對劑量的影響最大.根據實驗分析結果,將計劃的總劑量等比例嚮上歸一,將總劑量增加2％,可瀰補治療床和體位固定裝置對放療劑量的衰減,提高總的射野通過率.結論 在設計治療計劃中照射野的入射方嚮時,應儘量使機架角度避開65°～70°和115°～125°及對側的290°～295°和230°～245°兩箇入射範圍.由于治療床和體位固定裝置對後斜野照射劑量衰減有影響,因此應在TPS中針對劑量衰減值進行相應的劑量補償.
목적 연구의과체PRECISE가속기C형비형치료상급체위고정장치대치료계화사야제량전체정학성적영향,병탐색일충소제해영향적방법.방법 장고체수화전리실진행CT소묘병장소묘도상전도치료계화계통(TPS)중.재TPS중설치조사삼수:선용6 MV적X사선、100 MU궤기도수,사야대소분별위5 cm×5 cm화10 cm×l0 cm,종궤가각0°개시,재0°～180°구간내매격5°위간격정의사야입사방향진행등중심조사.안조TPS중설치적조건분별측량대유급무치료상C형비화체위고정장치시적절대제량,장측량결과진행기록병분석.재MatriXX이유전리실구진계통상집행동양적조사야계화,사용OmniPro I'mRT연건중"add constant value"공능,조출최합괄적증가총제량적계수인자.선취6례분강종류환자제량증가전후적조강방료계화험증해인자능부소제치료상급체위고정장치대치료계화사야제량적쇠감.결과 방사치료중가속기치료상급체위고정장치대후사야조사제량쇠감유일정적영향,재65°～70°화1 15°～125°량개입사범위대제량적영향최대.근거실험분석결과,장계화적총제량등비례향상귀일,장총제량증가2％,가미보치료상화체위고정장치대방료제량적쇠감,제고총적사야통과솔.결론 재설계치료계화중조사야적입사방향시,응진량사궤가각도피개65°～70°화115°～125°급대측적290°～295°화230°～245°량개입사범위.유우치료상화체위고정장치대후사야조사제량쇠감유영향,인차응재TPS중침대제량쇠감치진행상응적제량보상.
Objective To investigate the influence of treatment table with C-arm and immobilization device in IMRT planning accuracy, and to explore methods to solve this problem.Methods The solid water slabs and the ionization chamber was scanned and images were transmitted to the treatment planning system (TPS).Beam parameters in the TPS were set with 6 MV beam and 100 MU exposures were used.Measurements were performed at two different sizes of 5 cm×5 cm and 10 cm×10 cm.The gantry was rotated through angles from 0° to 180° with measurements taken at 5° increments.The measure point was set at center of the ionization chamber' measure point, which was also the central point of planning.The center axis of Matrix was aligned with the center of couch and was irradiated in accordance with the same conditions.OmniPro-FmRT software was used to compare and analyze the dose distribution of the radiation field of measurement and the treatment planning system output.Using the function of add constant value to find the appropriate coefficient to improve the plan total dose.The dose distributions for each beam in IMRT plans which was increased or unincreased total dose were measured for 6 patients with pelvic tumor respectively.Results In radiation therapy, treatment couch and immobilization device may attenuate radiotherapy dose.The impact of the incident range from 65°-70° and 115°-125° were the largest.Increasing the total dose of the treatment plan by 2％ could compensate the attenuation of the treatment table and immobilization device.Conclusions In radiation therapy, the impact of the incident range from 65°-70°, 115°-125° and another side of 290°-295° and 230°-245° should be avoided.The attenuation should not be neglected in the TPS and dose should be compensated by adjusting beams' MU.
