Creation of waterproof, TLD probes for dose measurements to validate image-based radiopharmaceutical therapy dosimetry workflow.
Creation of waterproof, TLD probes for dose measurements to validate image-based radiopharmaceutical therapy dosimetry workflow.
复制标题
创建用于剂量测量的防水 TLD 探头，以验证基于图像的放射性药物治疗剂量测定工作流程。
DOI：
10.1088/2057-1976/accf22
复制
发表时间：
2023
影响因子：
1.4
通讯作者：
Bednarz,BryanP
中科院分区：
文献类型：
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作者：
Adam,DavidP;Hammer,Clifford;Malyshev,JuliaZiege;Culberson,WesleyS;Bradshaw,TylerJ;Grudzinski,JosephJ;Harari,PaulM;Bednarz,BryanP
基于核医学图像的体素水平剂量测量提供了放射药物治疗(RPT)治疗的患者特定个性化。正在出现的临床证据表明，与MIRD相比，使用体素水平剂量测量可以提高患者的治疗精度。体素水平剂量学需要对患者体内的活动浓度进行绝对量化，但SPECT/CT扫描仪的图像不是定量的，需要使用核医学模体进行校准。虽然模式化研究可以验证扫描仪恢复放射性浓度的能力，但这些研究只提供了感兴趣的真实指标：吸收剂量的替代指标。使用热释光剂量计(TLD)进行测量是一种通用且准确的测量吸收剂量的方法。在这项工作中，制造了一种TLD探头，可以安装在目前可用的核医学模体中，用于测量RPT试剂的吸收剂量。然后，将748MBq的I-131注入一个16ml的中空源球中，放置在6.4 L Jaszczak体模中，另外还有6个TLD探针，每个探针含有4个TLD-100 1×1×1 mm TLD-100(LiF：Mg，Ti)微立方体。该模型随后接受了符合I-131标准SPECT/CT成像方案的SPECT/CT扫描。然后将SPECT/CT图像输入到基于蒙特卡洛的RPT剂量测量平台RAPID中，并估计体模中的三维剂量分布。此外，使用体模的风格化表示创建了GEANT4基准测试场景(表示为“理想化”)。6种探针测定结果的一致性较好，−为5.5%~0.9%。计算了测量的GEANT4情景和理想化的GEANT4情景之间的差异，范围为−4.3%和−20.5%。这项工作表明，TLD测量与RAPID之间有很好的一致性。此外，它还介绍了一种新的TLD探头，该探头可以很容易地引入临床核医学工作流程，为RPT治疗提供基于图像的剂量测量的质量保证。
Voxel-level dosimetry based on nuclear medicine images offers patient-specific personalization of radiopharmaceutical therapy (RPT) treatments. Clinical evidence is emerging demonstrating improvements in treatment precision in patients when voxel-level dosimetry is used compared to MIRD. Voxel-level dosimetry requires absolute quantification of activity concentrations in the patient, but images from SPECT/CT scanners are not quantitative and require calibration using nuclear medicine phantoms. While phantom studies can validate a scanner's ability to recover activity concentrations, these studies provide only a surrogate for the true metric of interest: absorbed doses. Measurements using thermoluminescent dosimeters (TLDs) are a versatile and accurate method of measuring absorbed dose. In this work, a TLD probe was manufactured that can fit into currently available nuclear medicine phantoms for the measurement of absorbed dose of RPT agents. Next, 748 MBq of I-131 was administered to a 16 ml hollow source sphere placed in a 6.4 L Jaszczak phantom in addition to six TLD probes, each holding 4 TLD-100 1× 1× 1 mm TLD-100 (LiF: Mg, Ti) microcubes. The phantom then underwent a SPECT/CT scan in accordance with a standard SPECT/CT imaging protocol for I-131. The SPECT/CT images were then input into a Monte Carlo based RPT dosimetry platform named RAPID and a three dimensional dose distribution in the phantom was estimated. Additionally, a GEANT4 benchmarking scenario (denoted'idealized') was created using a stylized representation of the phantom. There was good agreement for all six probes, the differences between measurement and RAPID ranged between− 5.5% and 0.9%. The difference between the measured and the idealized GEANT4 scenario was calculated and ranged from− 4.3% and− 20.5%. This work demonstrates good agreement between TLD measurements and RAPID. In addition, it introduces a novel TLD probe that can be easily introduced into clinical nuclear medicine workflows to provide QA of image-based dosimetry for RPT treatments.