90Y PET-based dosimetry after selective internal radiotherapy treatments
90Y PET-based dosimetry after selective internal radiotherapy treatments
复制标题
DOI：
10.1097/mnm.0b013e3283524220
复制
发表时间：
2012-06-01
影响因子：
1.5
通讯作者：
Bagni, Oreste
中科院分区：
文献类型：
--
作者：
D'Arienzo, Marco;Chiaramida, Paola;Bagni, Oreste
目的Y-90的衰变有一个小的分支到Zr-89的O+第一激发态，其去激发到基态之后是β（+）-β（-）发射，该发射最近被用于选择性内照射（SIRT）治疗后的生物分布评估。本研究的目的是证明Y-90 PET成像的可行性，放射性栓塞后的剂量评估与Y-90 micropheres.Methods活动量化验证通过初步的幻影研究使用圆柱体体模组成的6个插入不同的体积填充有校准的安装Y-90 micropheres. Methods。使用配备锗酸铋（BGO）晶体的GE Discovery ST PET/CT扫描仪进行图像采集。图像重建采用有序子集期望最大化方法。研究了对象大小和迭代次数对剂量评估和体积恢复的影响。然后对一名接受肝脏SIRT治疗的患者（一个病灶）进行微球剂量分布评估。剂量计算采用我们部门开发的基于MATLAB的代码进行。执行专用Monte Carlo计算，以评价Y-90源的剂量S值。来自Y-90 PET采集的活性分布与体素S-值进行卷积，以获得三维吸收剂量分布和剂量体积histograms.Results剂量学研究进行了有序子集的期望最大化算法，三次迭代，在确定吸收剂量在最大插入的准确性为7.62%的体模。剂量差异随着插入件尺寸减小而增大。患者的初步结果提供了高分辨率的吸收剂量分布图。肿瘤区域的平均剂量为139.3戈伊，最大剂量高达237.9戈伊。健康肝脏的吸收剂量低于耐受剂量35戈伊（33.8戈伊）。一个明确的吸收剂量和肿瘤反应之间的相关性，观察在F-18-氟脱氧葡萄糖PET收购6个月后treatment.Conclusion根据我们的经验，Y-90 PET是一个有前途的和可靠的技术微球剂量评估，并可能铺平了道路，为患者特定的PET为基础的剂量测定肝SIRT治疗后。Nucl Med Commun 33：633-640（c）2012 Wolters Kluwer Health垂直栏Lippincott威廉姆斯& Wilkins。
Objectives The decay of Y-90 has a minor branch to the O+ first excited state of Zr-89, the de-excitation of which to the fundamental state is followed by a beta(+)-beta(-) emission that has been used recently for biodistribution assessment after selective internal radiotherapy (SIRT) treatments. The purpose of the present study is to demonstrate the feasibility of Y-90 PET imaging for dose assessment after radioembolization with Y-90 microspheres.Methods Activity quantification was validated through preliminary phantom studies using a cylindrical body phantom composed of six inserts of different volumes filled with a calibrated a mount of Y-90 microspheres. A GE Discovery ST PET/CT scanner provided with bismuth germinate (BGO) crystals was used for image acquisition. Images were reconstructed with an ordered subset expectation-maximization method. The effect of object size and the effect of the number of iterations on dose evaluation and volume recovery were investigated. Microsphere dose distribution was then evaluated on one patient (one lesion) who underwent liver SIRT treatment Dose calculations were made with a MATLAB-based code developed in our department. Dedicated Monte Carlo calculations were executed to evaluate dose S-values for the Y-90 source. The activity distribution derived from Y-90 PET acquisitions was convolved with the voxel S-values to obtain a three-dimensional absorbed dose distribution and dose-volume histograms.Results Dosimetry studies carried out on the body phantom with ordered subset expectation-maximization algorithm, three iterations, provided an accuracy of 7.62% in determining the absorbed dose in the largest insert. The dose difference increases as the insert size reduces. Preliminary results on a patient provided a high-resolution absorbed dose distribution map. An average dose of 139.3 Gy was evaluated for the tumor area, with a maximum dose as high as 237.9 Gy. The absorbed dose to the healthy liver was below the tolerance dose of 35 Gy (33.8 Gy). A clear correlation between absorbed dose and tumor response was observed at F-18-fluorodeoxyglucose PET acquired 6 months after treatment.Conclusion According to our experience, Y-90 PET is a promising and reliable technique for microsphere dose assessment and might pave the way for a patient-specific PET-based dosimetry after liver SIRT treatments. Nucl Med Commun 33:633-640 (c) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.