Quantitative SPECT for Targeted Radionuclide Therapy

近年来，SPECT成像取得了许多进展，包括在 重建和补偿方法，以及成像系统。然而，这些工作中的大部分都是 旨在改进诊断程序。定量成像信息的收集是一种 靶向放射性核素治疗(TRT)剂量学和治疗计划的关键步骤。中的错误 定量成像方法可能导致疗效降低或不良副作用发生率增加。 TRT剂量测定最常用的定量方法是共轭视图平面成像，即 这种方法是20多年前首创的。该项目的目标是开发、优化和评估， 用于体内评估的实用和临床可实施的定量成像方法 累积活度(即，在一个区域或器官中发生的放射性衰变的次数 时间)。这些方法将基于平面扫描和一次或多次SPECT扫描的组合 SPECT/CT系统，使用定量SPECT重建和平面处理进行处理 技巧。具体地说，针对Ln-111和1-131光子发射的SPECT重建算法 考虑到散射、衰减、部分体积效应以及准直器的穿透和散射 发展起来的。结合侧位和AP成像采集和器官的平面成像方法 将检查基于SPECT扫描的重叠校正，以改善器官和肿瘤的勾画，并 放射性定量。蒙特卡罗模拟、物理模型和患者数据将用于 优化和验证方法。一群数学幻影，基于以下结果 患者研究，将被开发并用于模拟各种解剖和药代动力学。成像 参数和获取技术将根据它们对估计的影响进行评估 剂量学参数。定量成像是剂量计算的关键输入，而剂量计算对于 TRT治疗计划。本提案中描述的工作将开发和验证以下方法 以实用和临床可实施的方式改进量化。如果成功，这个项目将允许 开发更准确的治疗计划，有可能获得更大的治疗效果和更少的治疗 不良反应。它还将为临床研究提供有价值的方法学改进 了解TRT剂量-反应关系。

In recent years there have been a number of advances in SPECT imaging including improvements in reconstruction and compensation methods, and imaging systems. However, much of this work has been targeted at improvement of diagnostic procedures. The collection of quantitative imaging information is a critical step in dosimetry and treatment planning for targeted radionuclide therapy (TRT). Errors in the quantitative imaging methods can result in reduced efficacy or increased incidence of adverse side effects. The most commonly used quantitation methodology for TRT dosimetry is conjugate-view planar imaging, a method pioneered more than 20 years ago. The goal of this project is to develop, optimize, and evaluate, practical and clinically implementable quantitative imaging methods for use in estimating in vivo the cumulated activity (i.e., the number of radioactive decays that occur in a region or organ integrated over time). The methods will be Dased on combinations of planar and one or more SPECT scans performed on a SPECT/CT system and processed using quantitative SPECT reconstruction and planar processing techniques. Specifically, SPECT reconstruction algorithms for ln-111 and 1-131 photon emissions that account for scatter, attenuation, partial volume effects, and collimator penetration and scatter will be developed. Planar imaging methods that incorporate lateral as well as AP imaging acquisition and organ overlap correction based on SPECT scans will be examined to improve organ and tumor delineation and radioactivity quantitation. Monte Carlo simulations, physical phantoms, and patient data will be used to optimize and validate the methodologies. A population of mathematical phantoms, based on the results of patient studies, will be developed and used to model various anatomies and pharmacokinetics. The imaging parameters and acquisition techniques will be evaluated in terms of their influence on the estimation of dosimetric parameters. Quantitative imaging is a critical input to dosimetry calculations that are essential to TRT treatment planning. The work described in this proposal will develop and validate methodologies for improving quantitation in a practical and clinically implementable manner. If successful, this project will allow the development of more accurate treatment plans with the potential for greater therapeutic effect and fewer adverse reactions. It will also provide valuable methodological improvements for clinical studies trying to understand TRT dose-response relationships.