CAJ | 학술논문

目的研究移动式术中放疗电子加速器(Mobetron)在手术室中的剂量分布特征,为制定相应防护措施与标准提供基础数据.方法对于常用的电子束能量9 MeV,在50、100、150和200 cm 4个高度平面,每个平面在每隔45°的8个方位上,距中心轴每隔50 cm处分别布放热释光剂量计.选择高度为100 cm的平面,对电子束能量为4、6、9、12 MeV的4个能量档位,进行对比测量.在10 Gy/min条件下出束10 Gy后测读热释光剂量计.结果 9 MeV时,在高度为100 cm的平面上,距中心参考点50、100、150和200 cm处的剂量当量平均值分别为169、756、395和241 μSv;在距中心参考点50 cm不同角度上的剂量与平均值最大相差9.1％.9 MeV时50、100、150和200 cm 4个高度平面各方向距中心轴100 cm处,平均剂量分别为527、756、570和141 μSv.而4、6、9和12MeV在100 cm高度平面90°上,距中心轴100 cm处的剂量分别为573、486、689和781 μSv.结论同一能量时,同一平面各角度上剂量都随距离增大呈幂指数衰减；同一高度平面,不同角度的剂量分布基本一致.不同高度平面上,100 cm平面的剂量最大.在不同能量档,剂量随能量的升高而增大.
목적 연구이동식술중방료전자가속기(Mobetron)재수술실중적제량분포특정,위제정상응방호조시여표준제공기출수거.방법 대우상용적전자속능량9 MeV,재50、100、150화200 cm 4개고도평면,매개평면재매격45°적8개방위상,거중심축매격50 cm처분별포방열석광제량계.선택고도위100 cm적평면,대전자속능량위4、6、9、12 MeV적4개능량당위,진행대비측량.재10 Gy/min조건하출속10 Gy후측독열석광제량계.결과 9 MeV시,재고도위100 cm적평면상,거중심삼고점50、100、150화200 cm처적제량당량평균치분별위169、756、395화241 μSv;재거중심삼고점50 cm불동각도상적제량여평균치최대상차9.1％.9 MeV시50、100、150화200 cm 4개고도평면각방향거중심축100 cm처,평균제량분별위527、756、570화141 μSv.이4、6、9화12MeV재100 cm고도평면90°상,거중심축100 cm처적제량분별위573、486、689화781 μSv.결론 동일능량시,동일평면각각도상제량도수거리증대정멱지수쇠감；동일고도평면,불동각도적제량분포기본일치.불동고도평면상,100 cm평면적제량최대.재불동능량당,제량수능량적승고이증대.
Objective To study the dose distribution characteristics formobile intra-operative radiotherapy accelerator (Mobetron) in an operating room,and to provide basic data for developing appropriate radiation protection measures and protection standard.Methods For most commonly used electron energy 9 MeV,TLD dosimeters were placed at 50,100,150 and 200 cm high plane,respectively.For each plane,the measurement points were selected at every 50 cm from the central axis at every 45° at eight different directions.Also different electron energies,such as 4,6,9 and 12 MeV,were taken into consideration at the plane at 100 cm height.After 10 Gy with a dose rate of 10 Gy/min were delivered,the TLD dosimeters were used to read out the data.Results For 9 MeV,at the phantom plane(100 cm high plane),the average doses were 169,756,395 and 241 μSv at 50,100,150 and 200 cm from the central axis,respectively.Themaximum deviation between the doses at 50 cm from the central axis in different angles and their average values were 9.1％.In the identical angle,the average doses of 50,100,150 and 200 cm high planes at the distance of 100 cm from central axis were 527,756,570 and 141 μSv,respecitvely.For the energies of 4,6,9 and 12 MeV,the average doses were 573,486,689 and 781 μSv at 100 cm from the central axis at 90° of 100 cm high plane.Conclusions For the same energy,the dose values at different directions were decreased by the minus exponential function law with the distance.The doses were uniformly distributed at different directions at the same distance from the central axis.The doses on the plane of 100 cm height were much higher than those at other heights,and the dose values were increased with the election energy.