电离室矩阵用于加速器质量保证:X射线

Application of Ionization Chamber Array in Quality Assurance of Linear Accelerator:X Ray

目的:探讨利用二维电离室矩阵MatriXX进行医用直线加速器质量保证的方法及可靠性。方法:在点剂量的质量保证中,将MatriXX系统在特制水箱中测得的数据与0.6 cc电离室在标准水箱中的剂量测量值作比较,从而定出Ma-triXX的校准系数,以此来校准射线的输出量和能量。在面剂量的质量保证中,用MatriXX测量医用加速器射线野的对称性、平坦度以及辐射野的大小及中心轴偏离,将测量结果与RFA300三维水箱扫描结果及控制台显示数值进行比较分析。结果:用MatriXX加有机玻璃板可准确快捷地完成对射线输出量和能量的校准。用MatriXX所测射野的对称性和平坦度及射线野大小与RFA300水箱的测量数据一致。结论:MatriXX系统进行加速器的质量保证简便可靠。

Objective： To investigate the method and feasibility of 2D ionization chamber array MatriXX system in quality assurance of linear accelerator. Methods： The outputs and the energy levels irradiated for phonton beams measured by MatriXX in a water phantom specially designed were compared with the data acquired by 0.6 cc ionization chamber with the standard water phantom. The comparison fixed on a correction factor which was used to check the output and energy. The symmetry and flatness and field sizes of the photon beam measured by MatriXX system were compared with the data acquired by RFA300 3D scanner and the digit display of field size showed in the console. Results： The Output arid the energy level are calibrated accurately and quickly by MatriXX system. The symmetry, flatness and field sizes of the beam measured by MatriXX system are coincident with the data acquired by RFA300 3D scanner and the data showed in the console. Conclusions： The MatriXX system is very convenient and feasible in the quality assurance of linear accelerator.