脑转移瘤局部病灶加量容积旋转调强放疗海马体剂量学研究

发布时间：2018-04-02 13:09

本文选题：快速容积旋转调强　切入点：脑转移瘤　出处：《中华肿瘤防治杂志》2017年06期

【摘要】：目的在脑转移瘤放射治疗中,对海马体的保护得到了越来越多的重视和研究。本研究探讨容积旋转调强放疗在脑转移瘤局部病灶加量对海马体保护的剂量学特点。方法随机选取2013-12-01-2015-12-01在秦皇岛市第一医院放疗科治疗的15例脑转移患者,每例患者分别设计两种治疗计划,剂量体积约束条件相同,容积旋转调强放疗(volume-modulated arc therapy,VMAT)计划使用2个全弧,固定野调强放疗(fixed-field intensity modulated radiation therapy,ff-IMRT)计划使用9个共面射野。在处方剂量要求相同情况下,比较两种计划的靶区和海马体的剂量学参数、机器跳数差异。结果靶区剂量学参数中,VMAT计划的计划靶区体积(planning tumor volume,PTV)适形指数(0.82±0.07)好于ff-IMRT计划(0.78±0.08),t=2.457,P=0.028;对于海马体,左侧海马体最大值两计划差异无统计学意义,t=-1.175,P=0.260;VMAT计划的左侧海马体平均值为(1 186.43±1 358.29)cGy,右侧海马体最大值为(1 209.14±498.22)cGy,右侧海马体平均值为(738.16±422.70)cGy,双侧海马体最大值为(2 037.12±1 771.21)cGy,双侧海马体平均值为(940.68±765.00)cGy,低于ff-IMRT计划,差异有统计学意义,P0.05;对于正常组织(全身减计划靶体积,即B-P),VMAT计划的V5(36.69±15.39)%,V15(18.61±9.87)%,V20(13.09±7.45)%小于ff-IMRT计划,差异有统计学意义,P0.05,其他正常组织指标无差异;VMAT计划的机器跳数(426±74)显著低于ff-IMRT计划(1 122±317),t=-8.446,P0.001。结论 VMAT在脑转移瘤局部病灶加量与ff-IMRT相比,明显的减少了海马体的受量和机器跳数,靶区适形度较好,并部分减少了周围正常组织的低剂量区受量,具有一定的剂量学优势。
[Abstract]:Objective in radiotherapy of brain metastases, more and more attention has been paid to the protection of hippocampus.The purpose of this study was to investigate the dose characteristics of volume rotation intensity modulated radiotherapy (VIMRT) in the protection of hippocampal body from brain metastases.Methods Fifteen patients with brain metastases were randomly selected from the Department of radiotherapy, first Hospital of Qinhuangdao City, 2013-12-01-2015-12-01. Two treatment plans were designed for each patient with the same dose and volume constraint conditions. Volume rotated intensity modulated radiotherapy (VRT) volume-modulated arc therapeutic therapy (VMATT) was used for two full arcs.Fixed-field intensity modulated radiation therapy was planned to use nine coplanar fields.Under the same prescription dose requirement, the difference of dosimetry parameters and machine hops between the target area and the hippocampus of the two plans were compared.Results in the dosimetric parameters of the target area, the planning volume of tumor volume in the target area was 0.82 卤0.07, which was better than that in the ff-IMRT plan (0.78 卤0.08), and that in the hippocampal body was 0.78 卤0.08, 2.457 and 0.028, respectively, and the conformability index of the target area was 0.82 卤0.07, which was better than that of the ff-IMRT plan (0.78 卤0.08).The mean value of hippocampal body was 940.68 卤765.00 cGy, which was lower than that of ff-IMRT plan.Conclusion compared with ff-IMRT, the dosage of VMAT in brain metastases can significantly reduce the hippocampal receptivity and the number of machine jumps, the conformal degree of the target area is better, and partly reduce the low dose area of the surrounding normal tissue, so it has some dosimetric advantages.
【作者单位】：秦皇岛市第一医院放疗科;中南大学湘雅医院肿瘤科;
【分类号】：R730.55

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