Quantitative SPECT for Targeted Radionuclide Therapy

近年来，在SPECT成像中已经有了许多进展， 重建和补偿方法以及成像系统。然而，这项工作的大部分已经 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）剂量测定和治疗计划的关键步骤。中的错误 定量成像方法可导致功效降低或不良副作用的发生率增加。 TRT剂量测定最常用的定量方法是共轭视图平面成像， 20多年前开创的方法。该项目的目标是开发、优化和评估， 用于在体内估计的实用的和临床上可实施的定量成像方法 累积活动（即，在一个区域或器官中发生的放射性衰变的数量， 时间）。该方法将基于在一个或多个SPECT扫描上执行的平面和一个或多个SPECT扫描的组合。 SPECT/CT系统，并使用定量SPECT重建和平面处理进行处理 技术.具体而言，用于ln-111和1-131光子发射的SPECT重建算法， 考虑到散射、衰减、部分容积效应以及准直器穿透和散射， 开发平面成像方法，包括横向以及AP成像采集和器官 将检查基于SPECT扫描的重叠校正，以改善器官和肿瘤描绘， 放射性定量蒙特卡罗模拟、物理体模和患者数据将用于 优化和验证方法。一群数学幻象，基于 患者研究，将开发和用于模拟各种解剖结构和药代动力学。成像 参数和采集技术将根据其对估计的影响进行评估， 剂量学参数定量成像是剂量测定计算的关键输入， TRT治疗计划。本提案中所述的工作将制定和验证以下方法： 以实际和临床可实施的方式改进定量。如果成功，该项目将使 制定更准确的治疗计划，有可能获得更好的治疗效果， 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.