钴-60治疗机射野剂量的测量分析  

Measurement and analysis of the field dose using cobalt-60 therapy unit

作　　者：苗利[1] 李新民[1] 

机构地区：[1]苏州大学医学部放射医学与防护学院放射卫生学教研室江苏省放射医学与防护重点实验室,江苏苏州215123

出　　处：《苏州大学学报（医学版）》2012年第2期170-173,共4页Suzhou University Journal of Medical Science

摘　　要：目的通过测量钴-60治疗机在射野内的输出剂量率及其分布,获得当前剂量率的大小,并分析剂量分布的均匀性包括射野平坦度和对称性,以此来指导临床肿瘤放射治疗和放射医学实验。方法用指形电离室剂量计在源皮距80 cm处对20 cm×20 cm射野Cross-Plane和In-Plane方向取点测量,通过数据分析来评估钴-60治疗机的剂量率和射野内剂量的均匀性。结果得到5个方形野内当前的平均剂量率,可提供给使用者作为参考数据。钴-60治疗机的平坦度与对称性标准要求偏差±3%以内,分析结果基本符合。结论该钴-60治疗机的射野剂量分布较均匀,对肿瘤治疗或者放射医学实验的影响较小。Objective Measuring the field dose rate of cobalt-60 therapy unit to obtain the current dose rate and analyse the uniformity, including flatness and symmetry, of the dose distribution. Then the data can be used as guidance in tumor radiation therapy and radiation medical experiment. Methods U- sing thimble chamber to measure dose rate of radiation field（20 cm×20 cm） at 80cm of source skin dis- tance, including Cross-Plane and In-Plane direction, and analyse the flatness and symmetry. Results Five current mean dose rates of five square fields were obtained as user＇ s reference data. According to the tolerant deviation （±3 % ）, the analysis results showed that the deviation accorded with the criterion basi- cally. Conclusion It can be thought that the dose distribution of radiation field is uniform. It has little influence on tumor therapy or radiation medical experiment.

关 键 词：钴-60治疗机 剂量率 平坦度 对称性 

分 类 号：R815.2[医药卫生—放射医学] R815.5[医药卫生—临床医学]