不同模体材料对加速器绝对剂量校准的影响与分析  

Influence and Analysis of Different Phantom materials on Absolute Dose Calibration of Accelerator

作　　者：于得全[1] 高宏[1] 邵秋菊[1] 梁军[1] 

机构地区：[1]第四军医大学唐都医院放疗科,西安710038

出　　处：《医疗卫生装备》2012年第9期113-114,共2页Chinese Medical Equipment Journal

摘　　要：目的:探讨使用不同的模体材料如水、固体水校准加速器绝对剂量时对校准结果的影响程度,分析固体水模在不同能量挡时代替水模体的可行性。方法:分别采用水及PTW固体水测量Varian 21EX各个能量挡,测量探头板测量点深度为0.7 cm;6、9 MeV电子线测量深度为1 cm,需放置0.3 cm的固体水;12、16、20 MeV电子线测量深度为2 cm,需放置1.3 cm的固体水;6 MV X线测量深度为5 cm,需放置4.3 cm的固体水;15 MV X线测量深度为10 cm,需放置9.3 cm的固体水。结果:6、9、12、16、20 MeV电子线测量模体为固体水时比水分别小5.6%、2.8%、1.9%、0.7%、0.1%,6、15 MV X线测量模体为固体水时与水的差别分别为3.7%、3.6%。结论:校准12、16、20 MeV电子线及6、15 MV X线时固体水模可代替水模体,差别较小;6、9 MeV电子线因测量深度较浅,加之固体水是多个小单位固体水的叠加,测量差别较大,不易代替水测量。Objective To explore the use of different phantom materials, such as water and solid water, for the calibration of the accelerator absolute dose, and the feasibility of the replacement of water phantom by the solid water phantom with different energy levels. Methods PTW water and solids water were used to measure Varian 21EX with different energy levels. The point depth of the probe board was 0.7 era, and the measurement depth of 6,9 MeV electron beam was 1 era, when 0.3 cm solid water was needed; the measurement depth of 12,16 and 20 MeV beam was 2 cm, when 1.3 cm solid water was needed; the measurement depth of 6 MV X beam was 5 cm, when 4.3 cm solid water was needed; the measurement depth of 15 MV X beam was 10 era, when 9.3 em solid water was needed. Results The replacement of water phantom by solid water phantom resulted in 5.6%, 2.8%, 19%, 0.7% and 0.1% decrease respectively for 6, 9, 12, 16 and 20 MeV electron beams, and in 3.7% and 3.6% respectively for 6 and 15 MV X beams. Conclusion The water phantom can be replaced by the solid water phantom for 12, 16 and 20 MeV electron beams and 6, 15 MV X because of the little difference, while can not for 6 and 9 MeV electron beams for the significant difference.[Chirlese Medical Equipment Journal ,2012,33（9） ： 113-114]

关 键 词：模体材料 绝对剂量 校准 

分 类 号：R318.6[医药卫生—生物医学工程] TH774[医药卫生—基础医学]