摘要
目的 比较质子调强放疗(IMPT)、光子调强放疗(IMRT)、光子容积旋转调强放疗(VMAT)计划在颅脑内肿瘤患者放疗中剂量学优势.方法 选取山东省肿瘤医院质子中心2022-07-26-2022-11-08收治的10例颅脑内肿瘤患者分别设计IMPT、IMRT、VMAT计划,统计有代表性的剂量学数据:靶区适形度指数(CI),靶区均匀性指数(HI),梯度指数(GI),靶区最大点剂量、平均剂量,颅脑内平均剂量,2 Gy剂量对应体积(V2 Gy),5 Gy剂量对应体积(V5 Gy),10 Gy剂量对应体积(V10 Gy)以及脑干最大点剂量.结果 IMPT计划靶区平均剂量为(51.57±0.49)GyE,低于IMRT[(52.30±0.31)Gy]和 VMAT 计划[(52.38±0.35)Gy],Z 值分别为-3.161 和-3.180,均 P=0.001.IMPT 计划靶区覆盖率为(99.39±1.53)％,优于 IMRT[(99.30±0.76)％]和 VMAT 计划[(98.75±1.19)％],Z 值分别为 2.190 和 2.608,P 值分别为 0.029 和 0.009.VMAT 计划 CI 为 0.88±0.03,高于 IMRT(0.85±0.07)和 IMPT 计划(0.47±0.18),Z 值分别为-3.515 和-3.742,均 P＜0.001.IMPT 计划 V2 Gy为(492.16±172.51)cm3,优于 IMRT[(1 052.14±349.8)cm3]和 VMAT 计划[(1 165.9±320.12)cm3],Z 值分别为-3.213 和-3.515,P 值分别为 0.001 和＜0.001;V5 Gy 为(391.53±156.04)cm3,优于 IMRT[(826.00±318.16)cm3]和 VMAT 计划[(802.19±341.54)cm3],Z 值分别为-2.986 和-2.910,P 值分别为 0.003 和 0.004;V10 Gy 为(286.98±150.47)cm3,优于 IMRT 计划[(520.42±281.48)cm3],Z=-2.079,P=0.038.结论 光子IMRT、VMAT和质子IMPT技术均能满足临床要求.相比于光子,质子放疗有更少的低剂量区.但对于靠近靶区的危及器官,IMPT相比于IMRT和VMAT在控制最大点剂量方面无明显优势.
Abstract
Objective To compare the dosimetric advantages of intensity modulated proton therapy(IMPT),intensity mod-ulated radiation therapy(IMRT),and volume modulated arc therapy(VMAT)plans in radiotherapy for patients with intracranial tumors.Methods Ten patients with intracranial tumors admitted to the Proton Center of Shandong Cancer Hospital from July 26,2022 to November 8,2022 were selected to design IMPT,IMRT,and VMAT plans respectively.Representative dosimetry data were calculated:target conformability index(CI),target homogeneity index(HI),gradi-ent index(GI),maximum target dose,average dose,average intracerebral dose,V2 Gy,V5 Gy,V10 Gy,and the maximum dose received by the brainstem.Results The average dose of the IMPT program target area was(51.57±0.49)GyE,which was lower than that of IMRT[(52.30±0.31)Gy]and VMAT plan[(52.38±0.35)Gy],with Z values of-3.161 and-3.180,respectively,both P=0.001.The coverage rate of the IMPT program target area was(99.39±1.53)％,which was superior to IMRT[(99.30±0.76)％]and VMAT plan[(98.75±1.19)％],with Z values of 2.190 and 2.608,and P values of 0.029 and 0.009,respectively.The CI of VMAT plan was 0.88±0.03,higher than that of IMRT(0.85±0.07)and IMPT plan(0.47±0.18),with Z values of-3.515 and-3.742,respectively,both P＜0.001.The V2 Gy of the IMPT plan was(492.16±172.51)cm3,which was superior to the IMRT[(1 052.14±349.8)cm3]and the VMAT plan[(1 165.9±320.12)cm3].the Z values were-3.213 and-3.515,respectively,and the P values were 0.001 and＜0.001,respectively.V5 Gy was(391.53±156.04)cm3,which was superior to the IMRT[(826.00±318.16)cm3]and VMAT plan[(802.19±341.54)cm3],with Z values of-2.986 and-2.910,and P val-ues of 0.003 and 0.004,respectively.V10 Gy was(286.98±150.47)cm3,which was superior to the IMRT plan[(520.42±281.48)cm3],Z=-2.079,P=0.038.Conclusions IMRT,VMAT and IMPT can meet the clinical requirements.Proton radiotherapy has fewer low-dose regions than photons.However,for the endangered organs close to the target,IMPT has no obvious advantage over IMRT and VMAT in controlling the maximum point dose.
基金项目
国家自然科学基金(82172072)
山东省自然科学基金(ZR2020LZL001)
山东省自然科学基金(ZR2022QH188)
山东省泰山学者青年专家项目(tsqn201909140)
NETL
NSTL
万方数据