目的:研究在胸部肿瘤放疗过程中采用多程放疗的剂量学优势,并对多程放疗计划的划分阶段进行探索.方法:选取2022年5月至2023年10月在某院接受过胸部放疗且在放疗过程中修改过治疗计划的患者18例.所有患者采用Vari an Eclipse 15.6计划系统进行计划设计,采用容积旋转调强放疗(volume modulated arc therapy,VMAT)技术在Halcyon加速器上进行治疗.比较首程计划与二程计划的计划靶区和危及器官的剂量学参数,同时采用3％/2mm的标准对患者首程治疗过程中每个治疗野的穿射剂量一致性进行分析.结果:首程计划与二程计划靶区的适形性指数和均匀性指数相近,差异无统计学意义(P均＞0.05),二程计划靶区的体积明显缩小,差异有统计学意义(P＜0.05).修改治疗计划后,双肺的V5、V20、Dmean和心脏的V30均显著降低,差异有统计学意义(P＜0.05).随着治疗次数的增加,穿射剂量一致性逐渐下降,多数患者在首程放疗中断时穿射剂量一致性平均值为80.8％.结论:胸部肿瘤多程放疗能明显降低肺等危及器官的受照射剂量,穿射剂量一致性检测结果降低到80％附近时是修改治疗计划的最佳时机.
Dosimetric study of multi-stage radiotherapy for thoracic tumors
Objective To study the dosimetric advantages of multi-stage radiotherapy for thoracic tumors and the staging of multi-stage radiotherapy plan.Methods Totally 18 thoracic tumor patients who underwent thoracic radiotherapy and therapy plan modification during radiotherapy from May 2022 to October 2023 at some hospital were selected,who had the plan designed with Varian Eclipse 15.6 planning system and the radiotherapy performed with volume modulated arc therapy(V M AT)technique and Halcyon accelterator.The first-stage radiotherapy plan was compared with the second-stage plan in terms of the dosime-tric parameters of the planning target volume(PTV)and organs at risk(OARs),and consistency analysis was carried out for the penetration dose of each treatment field during the first therapy stage using the 3％/2 mm criterion.Results There were no significant differences between the two plans in conformity index(CI)and homogeneity index(HI)of the target volume(all P＞0.05),while the PTV of the second-stage plan was decreased significantly(P＜0.05).The V5,V20 andDmeanof the both lungs and the V30 of the heart were all lowered statistically after the plans were modified(P＜0.05).The penetration dose consistency decreased gradually with the increased times of treatment,and most of the patients had a mean penetration dose consistency of 80.8％at the time of interruption of the first-stage radiotherapy.Conclusions Multi-stage radiotherapy for thoracic tumors can reduce the radiation dose to OARs such as the lung,and it's the optimal timing for modifying the radiothe-rapy plan when the results of the penetration dose consistency are reduced to around 80％.[Chinese Medical Equipment Journal,2025,46(1):44-48]
multi-stage radiotherapythoracic tumordosimetric parameterconsistency of penetration doseHalcyon acce-lerator
万方数据
维普
