脑胶质瘤光子调强放疗与质子调强放疗计划剂量学对比研究

Dosimetric comparison of intensity-modulated photon radiotherapy planning and intensity-modulated proton radiotherapy planning for glioma

目的比较脑胶质瘤光子调强放疗(IMRT)计划与质子调强放疗(IMPT)计划的剂量学差异。方法回顾性分析2020年11月至2022年4月中国科学技术大学附属第一医院离子医学中心接受IMRT治疗的15例脑胶质瘤患者的临床资料。在治疗计划系统中分别为每例患者图像设计IMRT及IMPT计划, 比较两种计划靶体积(PTV)、靶区适合度指数(CI)、靶区剂量均匀性指数(HI)、危及器官的最大剂量(Dmax)及平均剂量(Dmean)差异。结果 IMRT计划组PTV1、PTV2的Dmax、Dmean、CI及HI与IMPT计划组比较, 差异均无统计学意义(均P>0.05)。与IMRT计划组相比, IMPT计划组脑干Dmean[6.92 GyE(0.09 GyE, 12.58 GyE)比24.41 GyE(2.59 GyE, 34.18 GyE)]、左侧视神经Dmax[0.78 GyE(0.04 GyE, 25.18 GyE)比20.42 GyE(6.38 GyE, 37.17 GyE)]、左侧视神经Dmean[0.10 GyE(0.01 GyE, 11.63 GyE)比9.74 GyE (2.99 GyE, 20.87 GyE)]、右侧视神经Dmean[1.57 GyE(0.13 GyE, 14.90 GyE)比14.08 GyE(2.66 GyE, 23.67 GyE)]、左侧晶体Dmax[0 GyE(0 GyE, 2.91 GyE)比4.84 GyE(1.42 GyE, 5.48 GyE)]、左侧晶体Dmean [0 GyE(0 GyE, 1.73 GyE)比3.84 GyE(1.25 GyE, 4.30 GyE)]、右侧晶体Dmax[0.25 GyE(0.04 GyE, 4.55 GyE)比4.28 GyE(1.58 GyE, 5.84 GyE)]、右侧晶体Dmean[0.16 GyE(0.01 GyE, 1.95 GyE)比3.73 GyE(1.04 GyE, 4.86 GyE)]、垂体Dmax[6.97 GyE(0.18 GyE, 39.70 GyE)比36.60 GyE(2.74 GyE, 45.19 GyE)]、垂体Dmean[1.36 GyE(0.06 GyE, 13.85 GyE)比24.74 GyE(2.42 GyE, 32.80 GyE)]、海马Dmax[5.10 GyE(0.24 GyE, 26.52 GyE)比35.83 GyE(5.03 GyE, 46.11 GyE)]、海马Dmean[0.36 GyE(0.04 GyE, 25.65 GyE)比18.79 GyE(2.37 GyE, 28.10 GyE)]均低, 差异均有统计学意义(均P<0.05)。IMPT计划组与IMRT计划组脑干Dmax[51.98 GyE(0.66 GyE, 53.43 GyE)比53.29 GyE(3.87 GyE, 53.48 GyE)]、右侧视神经Dmax [9.60 GyE(0.01 GyE, 43.32 GyE)比25.37 GyE(3.45 GyE, 41.25 GyE)]比较, 差异均无统计学意义(均P>0.05)。结论在脑胶质瘤放疗中, IMRT与IMPT计划均能满足放疗临床剂量要求, IMPT计划能更好保护周围危及器官, 减少海马、脑干、视神经、晶体、垂体的照射剂量。

Objective To compare the dosimetric difference between intensity-modulated photon radiaotherapy(IMRT)planning and intensity-modulated proton radiotherapy(IMPT)planning for glioma.Methods The clinical data of 15 glioma patients who underwent IMRT in ion medical center of the First Affiliated Hospital of USTC from November 2020 to April 2022 were retrospectively analyzed.IMRT planning and IMPT planning were designed for the image of each patient in the therapy planning system.Main dosimetric parameters were compared including plan target volume(PTV),coverage index(CI),dose homogeneity index(HI),and maximal dose(Dmax)and mean dose(Dmean)of organs at risk between both plans.Results There were no significant differences between IMRT planning and IMPT planning in terms of Dmax and Dmean of PTV1 and PTV2,CI and HI(all P>0.05).Compared with IMRT planning,brainstem Dmean[6.92 GyE(0.09 GyE,12.58 GyE)vs.24.41 GyE(2.59 GyE,34.18 GyE)],left optic nerve Dmax[0.78 GyE(0.04 GyE,25.18 GyE)vs.20.42 GyE(6.38 GyE,37.17 GyE)],left optic nerve Dmean[0.10 GyE(0.01 GyE,11.63 GyE)vs.9.74 GyE(2.99 GyE,20.87 GyE)],right optic nerve Dmean[1.57 GyE(0.13 GyE,14.90 GyE)vs.14.08 GyE(2.66 GyE,23.67 GyE)],left len Dmax[0 GyE(0 GyE,2.91 GyE)vs.4.84 GyE(1.42 GyE,5.48 GyE)],left len Dmean[0 GyE(0 GyE,1.73 GyE)vs.3.84 GyE(1.25 GyE,4.30 GyE)],right len Dmax[0.25 GyE(0.04 GyE,4.55 GyE)vs.4.28 GyE(1.58 GyE,5.84 GyE)],right len Dmean[0.16 GyE(0.01 GyE,1.95 GyE)vs.3.73 GyE(1.04 GyE,4.86 GyE)],pituitary Dmax[6.97 GyE(0.18 GyE,39.70 GyE)vs.36.60 GyE(2.74 GyE,45.19 GyE)],pituitary Dmean[1.36 GyE(0.06 GyE,13.85 GyE)vs.24.74 GyE(2.42 GyE,32.80 GyE)],hippocampus Dmax[5.10 GyE(0.24 GyE,26.52 GyE)vs.35.83 GyE(5.03 GyE,46.11 GyE)],hippocampus Dmean[0.36 GyE(0.04 GyE,25.65 GyE)vs.18.79 GyE(2.37 GyE,28.10 GyE)]in IMPT planning were lower,and the differences were statistically significant(all P<0.05).There were no statistical differences in brainstem Dmax[51.98 GyE(0.66 GyE,53.43 GyE)vs.53.29 GyE(3.87 GyE,53.48 GyE)],right optic nerve Dmax[9.60 GyE(0.01 GyE,43.32 GyE)vs.25.37 GyE(3.45 GyE,41.25 GyE)]of both plans(all P>0.05).Conclusion In the radiotherapy for glioma,IMRT and IMPT can meet the dose demand in clinic.Furthermore,IMPT planning can protect organs at risk and reduce radiation dose in hippocampus,brainstem,optic nerve,lens and pituitary.