Halcyon在早期鼻腔NK/T细胞淋巴瘤容积旋转调强计划中计划质量和执行效率研究

Radiotherapy plan quality and delivery efficiency for patients with early nasal cavity NK/T cell lymphoma treated by volumetric modulated arc therapy using Halcyon linac

目的基于Halcyon 2.0和VitalBeam加速器分析和评估早期鼻腔NK/T细胞淋巴瘤容积旋转调强(VMAT)计划质量和执行效率。方法回顾性分析2019-12-31-2021-03-03在郑州大学附属肿瘤医院行早期鼻腔NK/T细胞淋巴瘤VMAT计划的15例患者,在Eclipse 15.6计划系统中重新设计基于Halcyon、VitalBeam均整(FF)和无均整(FFF)治疗平台的VMAT计划,比较3种计划靶区和危及器官受量、机器跳数、执行时间和计划验证的差异。结果Halcyon早期鼻腔NK/T细胞淋巴瘤VMAT计划能够满足临床要求,靶区各剂量指标与VitalBeam平台相似。Halcyon计划中左晶体与右晶体的Dmax和Dmean均低于VitalBeam VMAT计划,其中Halcyon左、右晶体的Dmax与VitalBeam FF差异有统计学意义,均P<0.001,与VitalBeam FFF差异无统计学意义,均P>0.05;Halcyon左、右晶体的Dmean与VitalBeam FF和VitalBeam FFF差异均有统计学意义,P<0.05。Halcyon脑干与视交叉的Dmax和Dmean均低于VitalBeam VMAT计划,差异无统计学意义(脑干Dmax:F=0.022,P=0.978;脑干Dmean:F=0.533,P=0.591;视交叉Dmax:H=1.679,P=0.432;视交叉Dmean:F=0.942,P=0.398)。Halcyon计划的机器跳数高于VitalBeam FF和FFF平台,分别为487.13±49.05、432.19±50.30和466.83±72.89(F=3.388,P=0.043),其中Halcyon计划的机器跳数与VitalBeam FF差异有统计学意义,P=0.041。Halcyon、VitalBeam FF和FFF计划执行时间分别为(1.38±0.03)、(3.35±0.56)和(3.11±0.37)min(H=30.194,P<0.001),VitalBeam FF和FFF分别与Halcyon计划执行时间比较,差异均有统计学意义,均P<0.001。Halcyon和VitalBeam平台计划验证(2mm,3%)的γ通过率均>95%,满足临床要求。结论Halcyon加速器设计的VMAT治疗计划能满足临床要求,在早期鼻腔NK/T细胞淋巴瘤中减少了距离靶区较近晶体的受量,执行效率高,显著缩短了治疗时间。

Objective To analyze and evaluate the quality and delivery efficiency of volumetric modulated arc therapy(VMAT)plans for early nasal cavity NK/T cell lymphoma based on Halcyon and VitalBeam Accelerator.Methods A total of 15patients with early nasal cavity NK/T-cell lymphoma treated by VMAT radiotherapy at Affiliated Cancer Hospital of Zhengzhou University from December 12,2019to March 3,2021were randomly retrospectively selected for analysis.Three VMAT plans using Halcyon,VitalBeam FF and FFF linacs separately were redesigned using each patient's radiotherapy image data based on the treatment planning system(TPS)of Eclipse with the version 15.6.The difference in dose coverage of target and dose to organs at risk,monitor unit(MU)efficiency,delivery time,and verification passing rate of three plans were recorded and compared.Results The VMAT plan for early nasal cavity NK/T cell lymphoma based upon the Halcyon treatment platform could meet the clinical objectives.The dose indexes of the target volume in Halcyon plans was similar to those of VitalBeam plans.The max dose(Dmax)and mean dose(Dmean)of left and right lens in the Halcyon plan were lower than VMAT plan of VitalBeam platform,and the difference between Dmaxof Halcyon left and right lens and VitalBeam FF was statistically significant(both P<0.001);the difference between Dmaxof Halcyon left and right lens and VitalBeam FFF was not statistically significant(both P>0.05);the difference between Dmeanof Halcyon left and right lens and VitalBeam FF was statistically significant(both P<0.05)and the difference between Dmeanof Halcyon left and right lens and VitalBeam FFF was also statistically significant(both P<0.05).The Dmaxand Dmeanof the brainstem and optic chiasm in the Halcyon plan were lower compared with VitalBeam plan,the difference was not statistically significant(brainstem Dmax:F=0.022,P=0.978;brainstem Dmean:F=0.533,P=0.591;optic chiasm Dmax:H=1.679,P=0.432;optic chiasm Dmean:F=0.942,P=0.398).The MUs of the Halcyon plan was 487.13±49.05,which was significantly higher than 432.19±50.30of the VitalBeam FF plan and 466.83±72.89of the VitalBeam FFF plan(F=3.388.P=0.043).The delivery time significantly differed between the Halcyon[(1.38±0.03)min]with VitalBeam FF[(3.35±0.56)min],and VitalBeam FFF[(3.11±0.37)min](H=30.194.P<0.001).The average plan verification pass rate(2mm,3%)of Halcyon and VitalBeam plans were above 95%,meeting the clinical requirements.Conclusion The Halcyon plan can meet the clinical requirements,shorten treatment time and achieve a lower lens dose with high delivery efficiency in early nasal cavity NK/T-cell lymphoma.