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[目的]探讨利用治疗计划系统修正加速器治疗床对放疗剂量的影响。[方法]利用治疗计划系统设计两套(无床结构和有床结构)治疗计划,两计划中心点(测量点)的位置和剂量一样,计算不同角度的MU值。将固体水置于等中心处,改变机架角度,输入相应的MU值进行照射并实际测量,最后计算两套计划的误差。[结果]在110°～140°范围内,剂量补偿无效;在140°～180°范围内,与无床结构的计划相比,有床结构的计划的剂量误差从-2.25%～-3.29%减小到0.85%～1.55%,两种方法的测量结果差异具有统计学意义(P<0.01)。[结论]将治疗床结构加入到治疗计划设计中能够对治疗床板的影响做出相应的剂量修正,对于滑轨则无效,因此布野应该尽量避开治疗床两侧的滑轨,如果无法避开,治疗时应移动滑轨。
[Objective] To investigate the effect of using a treatment planning system to correct accelerator radiotherapy dose on radiotherapy. [Methods] With the treatment planning system, two treatment plans (no bed structure and bed structure) were designed. The position and dose of the two planned central points (measurement points) were calculated and the MU values at different angles were calculated. Place solid water at the isocenter, change the gantry angle, enter the corresponding MU value for illumination and actually measure, and finally calculate the error for both sets of plans. [Result] The dose compensation was ineffective in the range of 110 ° -140 °. The planned dose error of the bed structure was from -2.25% to -3.29% in the range of 140 ° -180 ° compared with the plan without bed structure. Reduced to 0.85% ~ 1.55%, the difference between the two methods was statistically significant (P <0.01). [Conclusion] Addition of the treatment bed structure to the treatment plan design can make the corresponding dose correction for the influence of the treatment bed board, and is invalid for the sliding rails. Therefore, the cloth field should avoid the sliding rails on both sides of the treatment bed if it can not be avoided , Treatment should be moved slide.