Functional Imaging, BC Cancer, Vancouver, British Columbia, Canada;
Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.
J Nucl Med. 2021 Dec;62(Suppl 3):36S-47S. doi: 10.2967/jnumed.121.262748.
In this work, we present details and initial results from a Lu dosimetry challenge that has been designed to collect data from the global nuclear medicine community aiming at identifying, understanding, and quantitatively characterizing the consequences of the various sources of variability in dosimetry. The challenge covers different approaches to performing dosimetry: planar, hybrid, and pure SPECT. It consists of 5 different and independent tasks to measure the variability of each step in the dosimetry workflow. Each task involves the calculation of absorbed doses to organs and tumors and was meant to be performed in sequential order. The order of the tasks is such that results from a previous one would not affect subsequent ones. Different sources of variability are removed as the participants advance through the challenge by giving them the data required to begin the calculations at different steps of the dosimetry workflow. Data from 2 patients after a therapeutic administration of Lu-DOTATATE were used for this study. The data are hosted in Deep Blue Data, a data repository service run by the University of Michigan. Participants submit results in standardized spreadsheets and with a short description summarizing their methods. In total, 178 participants have signed up for the challenge, and 119 submissions have been received. Sixty percent of submissions have used voxelized dose methods, with 47% of those using commercial software. In initial analysis, the volume of organs showed a variability of up to 49.8% whereas for lesions this was up to 176%. Variability in time-integrated activity was up to 192%. Mean absorbed doses varied up to 57.7%. Segmentation is the step that required the longest time to complete, with a median of 43 min. The median total time to perform the full calculation was 89 min. To advance dosimetry and encourage its routine use in radiopharmaceutical therapy applications, it is critical that dosimetry results be reproducible across centers. Our initial results provide insights into the variability associated with performing dose calculations. It is expected that this dataset, including results from future stages, will result in efforts to standardize and harmonize methods and procedures.
在这项工作中，我们介绍了 Lu 剂量学挑战的详细信息和初步结果，该挑战旨在从全球核医学社区收集数据，旨在确定、理解和定量描述剂量学中各种来源的变异性的后果。该挑战涵盖了进行剂量学的不同方法：平面、混合和纯 SPECT。它由 5 个不同且独立的任务组成，用于测量剂量学工作流程中每个步骤的变异性。每个任务都涉及器官和肿瘤吸收剂量的计算，旨在按顺序进行。任务的顺序是，参与者通过提供进行剂量学工作流程不同步骤计算所需的数据，从而在前一个任务的结果不会影响后续任务的情况下推进挑战。随着参与者通过挑战的进展，不同的变异性来源被消除，因为参与者通过挑战获得了进行剂量学工作流程不同步骤计算所需的数据。这项研究使用了 2 名接受 Lu-DOTATATE 治疗后患者的数据。数据托管在 Deep Blue Data 中，这是由密歇根大学运营的数据存储服务。参与者以标准化的电子表格提交结果，并以简短描述总结他们的方法。总共有 178 名参与者报名参加了这项挑战，收到了 119 份提交材料。60%的提交材料使用了体素剂量方法，其中 47%使用了商业软件。在初步分析中，器官体积的变异性高达 49.8%，而病变的变异性高达 176%。时间积分活性的变异性高达 192%。平均吸收剂量变化高达 57.7%。分割是完成时间最长的步骤，中位数为 43 分钟。完成全计算的中位数总时间为 89 分钟。为了推进剂量学并鼓励其在放射性药物治疗应用中的常规使用，剂量学结果在各个中心具有可重复性至关重要。我们的初步结果提供了有关执行剂量计算相关变异性的见解。预计该数据集，包括未来阶段的结果，将导致努力标准化和协调方法和程序。
