基于磁场调制的质子放疗新方法及其调制机制

发布时间：2018-04-27 00:23

  本文选题：蒙特卡罗方法 + 粒子输运　； 参考：《强激光与粒子束》2017年12期

【摘要】：提出一种基于磁场调制的质子放射治疗新方法,探索肿瘤剂量、正常器官剂量与磁场调制方法之间的关联机制,研究磁场调制质子放疗在器官环绕型肿瘤(肿瘤被正常器官环绕或包围)治疗中的应用。基于蒙特卡罗粒子输运程序Geant4,分别建立了理想器官环绕结构(由若干平行六面体结构组成)和含胰腺肿瘤人体腹部解剖结构两种几何构型。分别对两种几何构型内部施加磁场,通过改变磁场强度和方向,调制质子束布拉格峰几何位置,利用质子径迹的磁致偏转效应使质子束绕开正常器官对肿瘤进行照射。对于理想器官环绕型构型,磁场调制质子放疗可在保证95%剂量覆盖肿瘤情况下将受质子照射正常器官体积控制在接近于零的极低水平。对于胰腺肿瘤解剖构型,磁场调制方法可使质子束在调制磁场作用下,绕过脊髓和肾脏照射肿瘤,并使肿瘤被95%剂量较好地覆盖。通过磁场调制,可对质子束布拉格峰几何位置和质子径迹弯曲程度进行调制,绕过正常器官对肿瘤进行照射,从而最大限度地减少正常器官的受照体积和剂量。
[Abstract]:A new method of proton radiation therapy based on magnetic field modulation is proposed to explore the mechanism of correlation between tumor dose, normal organ dose and magnetic field modulation. To study the application of magnetic field modulated proton radiotherapy in the treatment of organ surrounding tumor (tumor surrounded or surrounded by normal organ). Based on Monte Carlo particle transport program Geant4, two geometries, ideal organ encircling structure (composed of several parallel hexahedron structures) and human abdominal anatomic structure with pancreatic tumor, were established. By changing the intensity and direction of the magnetic field and modulating the geometric position of the proton beam Bragg peak, the proton beam can be irradiated by the magnetic deflection effect of the proton track around the normal organs. For ideal organ encircling configuration, magnetic field modulated proton radiotherapy can control the normal organ volume of protonic irradiation to close to zero when 95% dose is guaranteed to cover the tumor. For the anatomical configuration of pancreatic tumors, the magnetic field modulation method can make the proton beam bypass the spinal cord and kidney to irradiate the tumor under the action of modulated magnetic field, and make the tumor better covered by 95% dose. The geometric position of the Bragg peak of the proton beam and the degree of curve of the proton track can be modulated by the magnetic field modulation, and the tumor can be irradiated by bypassing the normal organ, thus minimizing the radiation volume and dose of the normal organ.
【作者单位】： 南京航空航天大学核科学与工程系;哈尔滨医科大学附属肿瘤医院放射物理科;
【基金】：国家自然科学基金项目(11475087)
【分类号】：R730.55
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本文编号：1808357