MONTE CARLO SIMULATION OF HIGH ENERGY PHOTON IMAGING

高能光子成像的蒙特卡罗模拟

• 批准号: 6377075
• 负责人: YUNI K DEWARAJA
• 金额: $ 13.25万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6377075
• 关键词: bioimaging /biomedical imaging; computer simulation; iodine; mathematical model; neoplasm /cancer radioimmunotherapy; radionuclides; single photon emission computed tomography; technology /technique development

The long term objective of this work is to quantify uptake of high energy radionuclides such as I-131. Quantification of I-131 for internal dosimetry has gained renewed interest due to the recent success of radioimmunotherapy (RIT) in treating B-cell non-Hodgkin's lymphoma here at the University of Michigan and at other institutions. The latest data from the phase II RIT trial using I-131 labeled anti-B1 MoAb at this university shows the response rate to be 100 percent, with 71 percent of the responses being complete. We propose the use of Monte Carlo simulation for developing accurate SPECT quantification of I-131. A verified, fast, versatile Monte Carlo code suitable for simulating SPECT imaging of higher energy photon emitters is not presently available. We will carry out extensive verification tests to establish such a code which will then be applied to assess and solve significant problems in quantification such as scatter, penetration, attenuation and effects of object shape, size and background activity. We propose to build on the existing SIMIND and SKEPTIC Monte Carlo codes that are well established for low energy photons, and which have recently been expanded to include collimator scatter and penetration which is essential for accurate modeling of higher energy photons. Preliminary data comparing I-131 simulation results of SIMIND and SKEPTIC with measurements for simple geometries appear promising but their accuracy in modeling realistic imaging situations will be tested by the proposed research. The codes will also be verified for positron SPECT (511 keV photons) which is gaining interest as a low cost alternative to PET. We will improve and expand the two codes to include realistic simulation or backscatter photons, exact modeling of collimator hole shape and effects such as Doppler broadening. The more promising of the two codes will be parallelized in order to achieve significant speed-up, which is especially important when simulating tomographic acquisitions. Scatter- penetration correction is a pre-requisite for accurate quantification, and a main aspect of the present work will be Monte Carlo evaluation of scatter and collimator penetration in I-131 SPECT and assessment of compensation techniques that are based on spectral analysis. Fulfilling all aims of the proposed work will allow for accurate quantification which is necessary to predict response to therapy and for determining maximum activity to be administered. Apart from quantification, this work will have applications in the design of future imaging systems for high energy photons.

这项工作的长期目标是量化高摄取 能量放射性核素，例如I-131。 I-131的量化 由于最近的成功，内部剂量法已获得了新的兴趣 放射免疫疗法（RIT）治疗B细胞非霍奇金淋巴瘤 在密歇根大学和其他机构。 这 使用I-131标记为抗B1摩押的II期RIT试验中的最新数据 在这所大学，回应率为100％，有71 响应的百分比是完整的。 我们建议使用蒙特 Carlo模拟以开发I-131的精确频谱定量。 经过验证，快速，多功能的蒙特卡洛代码，适合模拟 较高能量光子发射器的SPECT成像目前不是 可用的。 我们将进行广泛的验证测试以建立 这样的代码然后将用于评估和解决大量的代码 量化的问题，例如散射，渗透，衰减和 物体形状，大小和背景活动的影响。 我们建议 建立在现有的模拟和怀疑论者的蒙特卡洛代码上 为低能光子建立，最近已经建立 扩展到包括准直仪散射和穿透性 对于较高能量光子的准确建模必不可少的。初步的 比较Simind和怀疑论I-131模拟结果的数据与 简单几何形状的测量似乎很有希望，但其准确性 在建模现实的成像情况时，将由提出的 研究。 这些代码也将用于正电子SPECT（511 KEV） 光子）正在获得兴趣作为宠物的低成本替代品。 我们将改进和扩展两个代码以包括现实的模拟 或反向散射光子，准确的准孔孔形状的确切建模和 诸如多普勒拓宽之类的效果。 这两个代码更有希望 将平行以实现大幅加速，即 在模拟层析成像采集时尤其重要。分散- 穿透性校正是准确定量的先决条件， 当前工作的一个主要方面将是蒙特卡洛评估 I-131 SPECT中的散射和准直仪穿透和评估 基于光谱分析的补偿技术。充实 拟议工作的所有目标都将允许准确量化 这是预测对治疗的反应和确定的必要条件 要进行的最大活动。 除了量化， 工作将在未来成像系统的设计中应用 高能光子。

项目成果

A 3-dimensional absorbed dose calculation method based on quantitative SPECT for radionuclide therapy: evaluation for (131)I using monte carlo simulation.

• 发表时间: 2002-08
• 期刊: Journal of nuclear medicine : official publication, Society of Nuclear Medicine
• 作者: M. Ljungberg;K. Sjögreen;Xiaowei Liu;E. Frey;Y. Dewaraja;S. Strand

A parallel Monte Carlo code for planar and SPECT imaging: implementation, verification and applications in (131)I SPECT.

用于平面和 SPECT 成像的并行蒙特卡罗代码：(131)I SPECT 中的实现、验证和应用。

• DOI: 10.1016/s0169-2607(01)00121-3
• 发表时间: 2002
• 期刊: Computer methods and programs in biomedicine
• 影响因子: 6.1
• 作者: Dewaraja,YuniK;Ljungberg,Michael;Majumdar,Amitava;Bose,Abhijit;Koral,KennethF
• 通讯作者: Koral,KennethF