School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Institute of Nuclear Medical Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Phys Med Biol. 2022 Mar 17;67(6). doi: 10.1088/1361-6560/ac58dd.
This paper describes the development and validation of a GPU-accelerated Monte Carlo (MC) dose computing module dedicated to organ dose calculations of individual patients undergoing nuclear medicine (NM) internal radiation exposures involving PET/CT examination.. This new module extends the more-than-10-years-long ARCHER project that developed a GPU-accelerated MC dose engine by adding dedicated NM source-definition features. To validate the code, we compared dose distributions from the point ion source, includingF,C,O, andGa, calculated for a water phantom against a well-tested MC code, GATE. To demonstrate the clinical utility and advantage of ARCHER-NM, one set ofF-FDG PET/CT data for an adult male NM patient is calculated using the new code. Radiosensitive organs in the CT dataset are segmented using a CNN-based tool called DeepViewer. The PET image intensity maps are converted to radioactivity distributions to allow for MC radiation transport dose calculations at the voxel level. The dose rate maps and corresponding statistical uncertainties were calculated at the acquisition time of PET image.The water-phantom results show excellent agreement, suggesting that the radiation physics module in the new NM code is adequate. The dose rate results of theF-FDG PET imaging patient show that ARCHER-NM's results agree very well with those of the GATE within -2.45% to 2.58% (for a total of 28 organs considered in this study). Most impressively, ARCHER-NM obtains such results in 22 s while it takes GATE about 180 min for the same number of 5 × 10simulated decay events.This is the first study presenting GPU-accelerated patient-specific MC internal radiation dose rate calculations for clinically realisticF-FDG PET/CT imaging case involving autosegmentation of whole-body PET/CT images. This study suggests that the proposed computing tools-ARCHER-NM- are accurate and fast enough for routine internal dosimetry in NM clinics.
本文描述了一个 GPU 加速的蒙特卡罗（MC）剂量计算模块的开发和验证，该模块专门用于进行接受核医学（NM）内照射的个体患者的器官剂量计算，涉及 PET/CT 检查。这个新模块扩展了超过 10 年历史的 ARCHER 项目，该项目通过添加专门的 NM 源定义功能，开发了一个 GPU 加速的 MC 剂量引擎。为了验证代码，我们比较了从点离子源（包括 F、C、O 和 Ga）计算的水模体的剂量分布，结果与经过充分验证的 MC 代码 GATE 一致。为了展示 ARCHER-NM 的临床实用性和优势，我们使用新代码计算了一组成人男性 NM 患者的 F-FDG PET/CT 数据。使用基于 CNN 的工具 DeepViewer 对 CT 数据集的敏感器官进行分割。将 PET 图像强度图转换为放射性分布，以便在体素水平进行 MC 辐射输运剂量计算。在 PET 图像采集时间计算剂量率图和相应的统计不确定性。水模体结果显示出极好的一致性，表明新 NM 代码中的辐射物理模块是充分的。F-FDG PET 成像患者的剂量率结果表明，ARCHER-NM 的结果与 GATE 的结果在 -2.45%到 2.58%之间非常吻合（在这项研究中总共考虑了 28 个器官）。最令人印象深刻的是，ARCHER-NM 在 22 秒内获得了这些结果，而 GATE 则需要大约 180 分钟才能获得相同数量的 5×10 个模拟衰变事件。这是第一个提出用于临床现实的 F-FDG PET/CT 成像案例的 GPU 加速患者特定 MC 内部辐射剂量率计算的研究，该案例涉及对全身 PET/CT 图像的自动分割。这项研究表明，所提出的计算工具——ARCHER-NM——足够准确和快速，可用于 NM 临床实践中的常规内部剂量测定。
