最小机器跳数对宫颈癌调强计划的影响

发布时间：2018-05-13 10:17

本文选题：宫颈肿瘤/调强放射疗法 + 放疗计划　；参考：《实用医学杂志》2015年15期

【摘要】：目的:探讨宫颈癌术后调强放疗计划设计中最小机器跳数对计划质量的影响,为计划设计时最小机器跳数的设置提供参考。方法:运用Pinnacle治疗计划的DMPO优化方式对10例宫颈癌病例进行调强计划设计,最小机器跳数分别取4 MU、5 MU、6 MU、8 MU、10 MU、12 MU、15 MU,每个患者共得到7个计划,所有计划的最小子野面积均取5 cm2,计划的优化目标与约束条件与最小机器跳数为4 MU的计划保持一致。处方剂量为95%PTV 45 Gy,1.8 Gy/次。根据剂量体积直方图统计靶区V95%、V105%、V110%、Dmean、适形指数(CI)及均匀指数(HI),危及器官受照射体积占总体积的百分比(V30%、V40%),子野数量及机器跳数。将结果与最小机器跳数为4 MU的计划相比较。结果:随着最小机器跳数的增加,V95%小幅降低,V110%与Dmean小幅增加,而V105%、增加的幅度较大,适形度降低,均匀性变差。统计学比较显示当最小机器跳数低于10 MU时,V105%、V110%、Dmean、CI、HI的均P0.05,当最小机器跳数≥10 MU时,靶区的部分剂量学指标开始出现显著性差异。随着最小机器的增加,子野数目显著降低,机器跳数及危及器官剂量的变化均未出现显著性差异。结论:在使用Pinnacle3治疗计划系统设计宫颈癌调强计划时,最小机器跳数可适当提高,这样不会引起靶区及危及器官剂量的显著改变,同时可以达到减少子野数量的效果。
[Abstract]:Objective: to investigate the effect of minimum machine hops on planning quality in the planning of IMRT for cervical cancer, and to provide a reference for setting the minimum machine hops in the planning design. Methods: ten cases of cervical cancer were designed with DMPO optimization method of Pinnacle treatment plan. The minimum machine hops were 4 MU5 MU5 MU6 MU10 MU10 MU10 MU12 MU15 MU15, and 7 schemes were obtained for each patient. The minimum field area of all plans is 5 cm ~ 2, and the optimization objective and constraint conditions are consistent with the plan with minimum machine hops of 4 MU. The prescription dose was 95%PTV 45 Gym 1.8 Gy/. According to the dose volume histogram statistics, the target area V95 / V105and V110105is Dmean, conformal index (CI) and uniform index (HI), which endangers the percentage of the irradiated volume to the total volume of the organ, V30 and V40, the number of fields and the number of machine hops. The results are compared with the minimum machine hops of 4 MU. Results: with the increase of the minimum number of machine hops, the V _ (110)% and Dmean increased slightly with the increase of V _ (95)%, while the amplitude of increase of V _ (105) was larger, the conformability decreased, and the uniformity became worse. Statistical comparison showed that when the minimum number of machine hops was less than 10 MU, the average value of V105 and V110CIHI was 0.05, and when the minimum number of hops was more than 10 MU, there was a significant difference in some dosimetric indexes in the target area. With the increase of the minimum number of machines, the number of subfields decreased significantly, and there was no significant difference in the number of machine hops and the dose of endangered organs. Conclusion: in the design of cervical cancer intensity modulation plan with Pinnacle3 treatment planning system, the minimum number of machine hops can be increased properly, which will not cause significant changes in target area and organ dose, and can also reduce the number of subfields.
【作者单位】：大连市第三人民医院放疗科;
【分类号】：R737.33;R730.55

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