基于Halcyon和Trilogy固定野调强计划质量和执行效率应用研究

he dosimetric and delivery efficiency between Halcyon-and Trilogy-based IMRT plans

目的基于Halcyon和Trilogy加速器的IMRT计划质量和执行效率差异分析研究。方法回顾分析基于Trilogy平台治疗完成的12例宫颈癌IMRT计划,将靶区和危及器官导入Eclipse15.1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、执行时间、子野面积差异以及Halcyon计划中近源端叶片与远源端叶片的子野面积差异。结果Halcyon平台计划能够满足临床要求,靶区各剂量指标与Trilogy平台计划相近。Halcyon计划中膀胱、直肠V30、Dmean,左侧股骨头V20、Dmean均低于Trilogy平台的IMRT计划(P=0.001~0.043)。Halcyon、Trilogy计划的机器跳数分别为(2316.7±209.7)、(1692.5±259.5)MU(P=0.000)。Halcyon、Trilogy计划执行时间分别为(3.01±0.28)、(12.38±1.49)min(P=0.000)。Halcyon近源端、远源端子野面积和Trilogy子野面积分别为(43.7±32.5)cm^2、(28.8±25.4)cm^2和(25.7±16.8)cm^2,Halcyon近源端子野与对应远源端子野面积比1.73±0.43,范围为0.71~6.28。结论Halcyon治疗平台能够满足临床要求,降低部分正常组织受量,执行效率更高,计划设计时应考虑近源端叶片与远源端叶片子野面积比。

Objective To compare the dosimetric and delivery efficiency between intensity-modulated radiation therapy (IMRT) plans based on Halcyon and Trilogy accelerator. Methods Clinical data of 12 patients with cervical cancer receiving Trilogy platform-based IMRT were retrospectively analyzed. The target area and organ at risk were introduced into the Eclipse version 15.1 TPS. The Halcyon-based IMRT was re-designed. The dose coverage of target area and organs at risk, monitor unit (MU) efficiency, delivery time and segment area and the differences between the proximal and distal segment area were statistically compared between two IMRT plans. Results The Halcyon treatment platform could meet the clinical objectives. Dose distribution of the target area was similar to that of the Trilogy plan (P >0.05). The volumes in the bladder and rectum receiving 30 Gy and the volumes in the left femoral head receiving 20 Gy of Halcyon plan and the mean dose (Dmean) of bladder, rectum and left femoral head were significantly lower compared with those of the Trilogy plan (P=0.001-0.043).The MUs of the Halcyon plan was 2 316.7±209.7, significantly higher than 1 692.5±259.5 of the Trilogy plan (P=0.000). The delivery time significantly differed between the Halcyon[(3.01±0.28) min] and Trilogy[(12.38±1.49) min](P=0.000).The average segment area of Halcyon plan for proximal and distal MLC was (43.7±32.5) cm^2 and (28.8±25.4) cm^2, the average segment area of Trilogy plan was (25.7±16.8) cm^2, the ratio of the proximal and distal segment area was 1.73±0.43, ranging from 0.71 to 6.28. Conclusions Halcyon treatment platform can meet the clinical requirements and reduce the dosage coverage of normal tissues with better delivery efficiency. The ratio of proximal and distal segment areas should be considered during the plan design.