二维半导体电离室矩阵在食管癌调强放射治疗剂量验证中的应用  

The application of two-dimensional semiconductor ionization chamber matrix in the dose verification of intensity modulated radiation therapy for esophageal cancer

作　　者：齐洪志[1] 杨玉刚[1] 郝洁[1] 许林[1] 尚革[1] QI Hong-zhi;YANG Yu-gang;HAO Jie(Cancer Center, The First Affiliated Hospital of Xinjiang Medical University, Urumchi 830054, China)

机构地区：[1]新疆医科大学第一附属医院肿瘤中心,新疆乌鲁木齐830054

出　　处：《中国医学装备》2017年第2期15-18,共4页China Medical Equipment

摘　　要：目的:探索Mapcheck二维半导体电离室矩阵在食管癌调强放射治疗(IMRT)剂量验证中的应用。方法:选取12例接受IMRT的食管癌患者,创建质量保证(QA)计划,并分别传入Mapcheck剂量验证系统和医用电子直线加速器。对12例患者的IMRT计划使用二维半导体电离室矩阵检测加速器剂量输出结果,并进行剂量结果分析。结果:采用业内普遍使用的计算网格3 mm,误差3%及阈值偏差10%的评判标准,实际测量的剂量分布与QA计划计算的剂量分布在对应的几何平面分布较为一致,在剂量偏差为3%、位移偏差3 mm和阈值偏差10%的条件下γ射线平均通过率为96.3%;剂量偏差5%、位移偏差5 mm的条件下γ射线平均通过率为99.9%。结论:二维半导体电离室矩阵操作相对简单,在测量要求和测量结果上完全能够满足临床需求,对指导放射治疗具有一定的意义。Objective: To explore the application of Mapcheck two-dimensional semiconductor ionization chamber matrix in the dose verification of intensity modulated radiation therapy (IMRT) for esophageal cancer. Methods: To select 12 esophageal cancer patients treated by IMRT and to create quality assurance (QA) plans for them, and introduce the Mapcheck dose verification system and the medical electron linear accelerator to the QA plans. To use the twodimensional semiconductor ionization chamber matrix to detect the dose output of accelerator for the 12 patientsand then analyze the dose results. Results: Grid 3 mm, 3% dose deviation and 10% deviation threshold were adoptedas criterion; at this criterion, the dose distribute of actual measured was consistency with QA plan on geometry planeand the Gamma-ray average passing rate was 96.3%; however, Gamma-ray average passing rate can achieve to 99.9%when dose deviation was 5% and displacement deviation was 5 mm. Conclusion: Two dimensional semicondu ctorionization chamber matrix operation is simpler than traditional operation, and it's measurement demand and measurement result can completely meet the clinical requirement, therefore, this operation is value and useful when guide clinical radiotherapy.

关 键 词：二维半导体电离室矩阵 剂量验证 质量保证 食管肿瘤 放射治疗 医用直线加速器 

分 类 号：R816.5[医药卫生—放射医学]