MULTIPLE SCATTERING THEORY APPLIED TO ELECTRON DOSIMETRY

多重散射理论应用于电子剂量测定

• 批准号: 3182025
• 负责人: DAVID JETTE
• 金额: $ 33.7万
• 依托单位: LAWRENCE H. LANZL INST OF MED PHYSICS
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-02 至 1997-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3182025
• 关键词: computed axial tomography; diagnosis quality /standard; electron radiation; mathematical model; neoplasm /cancer radiation therapy; phantom model; radiation dosage

Electron beams are now in widespread use in the radiation treatment of cancer because their rapid dose falloff minimizes irradiation of critical healthy tissues beyond the treatment volume. Unfortunately, for treatment planning purposes it is not yet possible to routinely calculate the absorbed dose distribution accurately, particularly in the presence of tissue inhomogeneities and body curvature. The overall goal of the proposed research is to develop electron dose-calculation algorithms which are sufficiently accurate for the most complicated situations expected to be encountered clinically, yet practical in the sense of being able to be implemented in a computerized treatment planning system (short enough calculation time). Our goal is to achieve in these computer algorithms an accuracy of 5%, or preferably 3%, throughout the treatment volume. During these final four years of the research, theoretical models already developed from the basic laws of physics will be mathematically simplified for implementation as computer algorithms. Several theoretical models for certain physical processes, still required, will also be developed at this time. EGS4 Monte Carlo calculations, to check the accuracy of the theoretical models and their attendant algorithms, will continually be carried out. The developing set of computer algorithms, using CT-Scan data directly as input, will be experimentally verified for accuracy through a consulting relationship with a university radiotherapy department. This comparison between the predictions of the algorithms and experimental results, starting with relatively simple configurations of inhomogeneities and progressing to use of a complex anthropomorphic phantom, will be carried out throughout the four years of the project.

电子束现在广泛用于放射治疗， 癌症，因为它们的快速剂量下降最大限度地减少了辐射的关键 治疗体积以外的健康组织。不幸的是为了治疗 规划目的，目前还不可能定期计算 准确的吸收剂量分布，特别是在存在 组织不均匀性和身体弯曲。的总体目标 建议的研究是开发电子剂量计算算法， 对于预期的最复杂情况， 在临床上会遇到，但在能够 在计算机化治疗计划系统中实施（足够短 计算时间）。我们的目标是在这些计算机算法中实现 在整个治疗体积中，精度为5%，或优选为3%。 在这最后四年的研究中，理论模型已经 从物理学基本定律发展而来的理论将在数学上得到简化 用于实现为计算机算法。几种理论模型 某些物理过程，仍然需要，也将在此开发 时间EGS4蒙特卡罗计算，以检查 理论模型及其伴随的算法，将继续被 贯彻正在开发的一套计算机算法，使用CT扫描数据 直接作为输入，将通过实验验证准确性， 与大学放射治疗部门建立咨询关系。这 算法的预测和实验之间的比较 结果，从相对简单的非均匀性配置开始 并逐步使用一个复杂的拟人化的幻影，将是 在该项目的四年中进行。