新型国产二维矩阵剂量验证系统的临床测试

目的:对新型国产二维矩阵剂量验证系统在临床条件下进行测试，检验其是否能够满足临床使用需要。方法:参照GB15213-94对用来检测国产二维矩阵剂量验证系统的医用直线加速器进行检测调整，使其达到国家标准。使用新型国产二维矩阵剂量验证系统，对标准照射野下的绝对剂量重复性，标准照射野下的剂量线性，平坦度、对称性，真实病例放疗计划验证进行测试。结果:标准照射野下的绝对剂量重复性检测，其变异系数小于0.7%，符合测试要求；标准照射野下的剂量线性检测与电离室检测结果相比，无明显差异；平坦度检测±3%以内、对称性检测±2%以内，均满足临床使用要求；真实病例计划验证γ通过率均大于98%，完全满足临床放疗计划验证要求。结论:新型国产二维矩阵剂量验证系统具备点剂量、面剂量测量功能，能够对加速器基本剂量性能进行检测，达到临床使用要求；能够实现放疗计划系统的DICOM数据导入，与实际测量结果比较分析，达到临床计划验证要求。

Clinical testing of a novel domestic two-dimensional matrix dosimetric verification system

Abstract: Objective To test a new type of domestic two-dimensional (2D) matrix dosimetric verification system in the clinical condition for evaluating whether the system can meet the clinical requirements. Methods The medical linear accelerator which was used to test the domestic 2D matrix dosimetric verification system was firstly tested and adjusted according to GB15213-94, thus ensuring that the accelerator met the national standard. Then the new type of domestic 2D matrix dose verification system is used for testing the repeatability of absolute dose measurement and dose linearity in the standard radiation field, flatness and symmetry, and validating actual radiotherapy plans. Results The test on the repeatability of absolute dose measurement in the standard radiation field showed that the coefficient of variation was less than 0.7%, which was consistent with the test requirements. There was no significant difference in the test results of dose linearity in the standard radiation field between 2D matrix dosimetric verification system and ionization chamber. The test also revealed that both flatness (within ±3%) and symmetry (within ±2%) met the clinical requirements. Moreover, the validation of actual treatment plans showed that the gamma passing rates were all above 98%, which fully satisfied the clinical requirements. Conclusion The novel domestic 2D matrix dosimetric system can be used to not only measure point and planar doses for the evaluation of the basic dose performances of the accelerator, but also realize the import of the DICOM data exported from the treatment planning system which are then compared with actual measurements, thereby meeting the clinical plan verification requirements.