Department of Nuclear Medicine, Pomeranian Medical University, Szczecin, Poland.
Nucl Med Rev Cent East Eur. 2022;25(1):37-46. doi: 10.5603/NMR.a2022.0008.
99mTc-hydrazinonicotinyl-Tyr3-octreotide ([99mTc]-HYNIC-TOC [Tektrotyd]) is a radiopharmaceutical used for the diagnosis of lesions with overexpression of somatostatin receptors. The purpose of this study was to optimize the method and estimate normal ranges for standardized uptake values of Tektrotyd in healthy livers.
An analysis of standardized uptake value (SUVs) normal ranges was performed for images acquired in a selected "healthy group" of 42 patients evaluated for neuroendocrin tumors. The "pathological group" comprised 20 patients with liver lesions detected by scintigraphic imaging. Normal ranges for radiopharmaceutical uptake values were estimated based on the quantitative analysis of images acquired with a GE Healthcare NM/CT 850 gamma camera.
The method for healthy liver segmentation in single photon emission computed tomography/computed tomography (SPECT/CT) was optimized. The normal range of SUVs for the liver was: standardized uptake value body weight (SUVbw) max [5.2-14.0] g/mL and standardized uptake value lean body mass (SUVlbm) [3.5-9.5] g/mL. The relative standard error (relative SE) of activity concentration estimated in the phantom study for the largest hot spheres was: ϕ = 37 mm - 5.9%, ϕ = 28 mm - 7.1%, ϕ = 22 mm - 11.4%, and ϕ = 17 mm - 22%.
Segmentation in the mid-coronal computed tomography (CT) image, at one-fourth of the height of the liver measured from the top, with a medium-sized volume of interest (VOI) outlined on a given transverse SPECT slice was regarded as the optimal method for estimating normal ranges for standardized uptake values. It is necessary to standardize quantification methods in the SPECT/CT studies. Our work is a step forward in obtaining standardization of SPECT/CT SUV calculation methods. Calculations for radiopharmaceutical uptake in tumors with volumes smaller than 5 mL are biased with a significant measurement error.
99mTc-肼基烟酰基-Tyr3-奥曲肽([99mTc]-HYNIC-TOC[Tektrotyd])是一种放射性药物，用于诊断过度表达生长抑素受体的病变。本研究旨在优化方法并估计健康肝脏中 Tektrotyd 标准化摄取值的正常范围。
对 42 例神经内分泌肿瘤患者进行评估的选定“健康组”的图像进行标准化摄取值(SUVs)正常范围分析。“病变组”包括 20 例通过闪烁成像检测到的肝脏病变患者。根据使用 GE Healthcare NM/CT 850 伽马相机获得的图像进行定量分析，估算放射性药物摄取值的正常范围。
优化了单光子发射计算机断层扫描/计算机断层扫描(SPECT/CT)中健康肝脏的分割方法。健康肝脏 SUVs 的正常范围为：标准化摄取值体重(SUVbw)max[5.2-14.0]g/mL和标准化摄取值去脂体重(SUVlbm)[3.5-9.5]g/mL。在体模研究中，最大热球的活性浓度估计的相对标准误差(相对 SE)为：ϕ=37mm-5.9%，ϕ=28mm-7.1%，ϕ=22mm-11.4%，和ϕ=17mm-22%。
在从中冠状 CT(CT)图像的四分之一处，在从顶部测量肝脏高度的四分之一处，在给定的横向 SPECT 切片上画出中等大小的感兴趣区(VOI)，被认为是估计标准化摄取值正常范围的最佳方法。需要对 SPECT/CT 研究中的定量方法进行标准化。我们的工作是在获得 SPECT/CT SUV 计算方法标准化方面迈出的一步。对于体积小于 5 毫升的肿瘤，放射性药物摄取的计算存在偏差，测量误差很大。
