标题： 基于两个二维平面测量的患者特异性人工智能生成三维剂量成像 显示英文标题

标题： Patient-specific AI for generation of 3D dosimetry imaging from two 2D-planar measurements

摘要： 在本工作中，我们探索了使用患者特定的强化学习从两个二维平面图像（前位和后位）生成三维活动图谱。 使用传统方法解决这个问题仍然不可行，并且在核医学中的剂量测定中具有特别的重要性，因为对于放射性药物如177Lu-PSMA的治疗后分布的方法通常是通过昂贵且耗时的三维SPECT获取或快速但仅限于二维的平面闪烁扫描进行的。 能够从平面闪烁扫描生成三维活动图谱为新的剂量测定应用打开了大门，消除了对SPECT的需求，并促进了多时间点剂量测定研究。 我们的解决方案包括生成一个患者特定的数据集，包含患者解剖结构内放射性药物可能的三维摄取图谱，随后采用一种人工智能方法（我们探索了3DUnet和扩散模型的使用）能够从二维平面图像生成三维活动图谱。 我们在模拟和实际平面采集中验证了我们的方法。 我们观察到使用患者特定的强化学习获得了更好的结果（MAE减少了约20%，SSIM增加了约5%），并且在结合扩散模型与患者特定训练时，器官分割和患者解剖结构更好，模拟的SSIM为0.89，与真实值相比，而与平面扫描后半小时进行的SPECT采集相比，SSIM为0.73。 我们认为，我们的方法可以为核医学剂量测定带来范式转变，仅使用平面闪烁扫描即可实现三维定量，而无需昂贵且耗时的SPECT，利用患者的治疗前信息。 显示英文摘要

摘要： In this work we explored the use of patient specific reinforced learning to generate 3D activity maps from two 2D planar images (anterior and posterior). The solution of this problem remains unachievable using conventional methodologies and is of particular interest for dosimetry in nuclear medicine where approaches for post-therapy distribution of radiopharmaceuticals such as 177Lu-PSMA are typically done via either expensive and long 3D SPECT acquisitions or fast, yet only 2D, planar scintigraphy. Being able to generate 3D activity maps from planar scintigraphy opens the gate for new dosimetry applications removing the need for SPECT and facilitating multi-time point dosimetry studies. Our solution comprises the generation of a patient specific dataset with possible 3D uptake maps of the radiopharmaceuticals withing the anatomy of the individual followed by an AI approach (we explored both the use of 3DUnet and diffusion models) able to generate 3D activity maps from 2D planar images. We have validated our method both in simulation and real planar acquisitions. We observed enhanced results using patient specific reinforcement learning (~20% reduction on MAE and ~5% increase in SSIM) and better organ delineation and patient anatomy especially when combining diffusion models with patient specific training yielding a SSIM=0.89 compared to the ground truth for simulations and 0.73 when compared to a SPECT acquisition performed half an hour after the planar. We believe that our methodology can set a change of paradigm for nuclear medicine dosimetry allowing for 3D quantification using only planar scintigraphy without the need of expensive and time-consuming SPECT leveraging the pre-therapy information of the patients.