调强放射治疗射野和剂量的验证

目的：为确保调强放射治疗的精确，利用自制和专用设备对每个射野的位置、形状和野内剂量分布进行验证。方法：用自制的位置验证标记球，贴在病人体表的某个固定位置，和病人一起进行CT扫描，设计计划时将此标记球设为位置验证靶区进行射野位置验证。利用加速器自带的射野影像系统（EPID）和治疗计划系统（TPS）的DRR图比对进行射野形状验证。利用Matrixx二维电离室矩阵和OnmiPro软件进行每个射野的剂量验证。结果：射野位置验证在统一调整系统后，误差结果满意。射野形状验证以3mm为标准，调整前的吻合率约为75％。剂量验证通过率大于等于95％的射野占77％。结论：通过81例鼻咽癌调强放疗的实验证明，利用上述三种方法对调强计划进行验证，可以及时纠正误差，确保计划准确执行。

Field Shape and Dose Verification of Intensity Modulated Radiotherapy

Objective:To insure the accuracy of intensity modulated radiotherapy,the field shape and dose of radiotherapy is verified with special hardware and device.Methods:To verify the field shape,a special marker is used and assumed as verification target.EPID and DRR picture is used to verify the shape of field.2D ionization Chamber array is used to verify the dose distribution.Results:After adjusting of system errors,the field verification results is satisfied.Take 3 mm as standard,the field shape verification results is 75%.Through Gamma method,the greater than 95% pass rate of approval is 77%.Conclusion:It has been found that three kinds of verifications can correct error and ensure the IMRT plan is executed properly.