一种新型加速器的乳腺癌固定野调强放射治疗中计划质量和执行效率评价

The plan quality and delivery efficiency of intensity modulated radiotherapy on a new designed linac for left side breast cancer

目的基于Halcyon加速器的乳腺癌固定野调强放射治疗(IMRT)计划质量和执行效率的研究。方法回顾分析基于Trilogy平台治疗完成的10例左侧乳腺癌IMRT计划,将靶区和危及器官导入Eclipse 15.1版本计划系统,重新设计基于Halcyon治疗平台的IMRT计划,比较两种计划靶区和危及器官受量、机器跳数、子野面积和执行时间差异。结果Halcyon左侧乳腺癌IMRT计划能够满足临床要求,靶区各剂量指标与Trilogy计划差异无统计学意义(P>0.05)。Halcyon计划中左肺的V10、V20、Dmean均低于Trilogy计划(Z=-2.22^-1.78,P<0.05),Halcyon计划心脏的V5为(27.80±7.66)%高于Trilogy计划的(23.18±8.19)%(Z=-0.71,P<0.05),Dmean为(7.03±1.80)Gy低于Trilogy计划的(7.11±2.40)Gy,但差异无统计学意义(P>0.05)。Halcyon计划的机器跳数为1 770.5±383.9,Trilogy计划的机器跳数为1 526.2±227.7,差异有统计学意义(Z=-1.44,P<0.05)。Halcyon计划执行时间为(3.01±0.28)min,Trilogy计划执行时间为(12.38±1.49)min,差异有统计学意义(Z=-3.42,P<0.05)。结论Halcyon加速器左侧乳腺癌IMRT在保证计划质量降低危及器官剂量的同时显著缩短了治疗时间。

Objective To analyze the dosimetric and delivery efficiency differences between IMRT plans based on Halcyon and Trilogy Accelerator for left side breast cancer.Methods A total of 10 patients with left side breast cancer based on the Trilogy platform were retrospectively analyzed.For each patient,plan based on Halcyon was redesigned using Eclipse Version 15.1 TPS.In order to evaluate plan quality,dose coverage of target and dose to organs at risk,monitor unit efficiency,segment size and delivery time were compared.Results Halcyon treatment platform could meet the clinical objective.Dose distribution of the target volume had no significant difference with the Trilogy plans(P>0.05).Volumes receiving 10 Gy,20 Gy and Dmean of the left lung were significantly reduced(Z=-2.22--1.78,P<0.05).V5 of heart for Halcyon and Trilogy was(27.80±7.66)%and(23.18±8.19)%,respectively(Z=-0.71,P<0.05),while Dmean was(7.03±1.8)Gy and(7.11±2.40)Gy,respectively(P>0.05).Halcyon increased the monitor unit from 1 526.2±227.7 by Trilogy to 1 770.5±383.9(Z=-0.71,P<0.05),but decreased the delivery time from(12.38±1.49)min by Trilogy to(3.01±0.28)min(Z=-3.42,P<0.05).Conclusion Halcyon treatment platform can meet the clinical requirements,reduce dose to normal tissue with high delivery efficiency.