Department of Nuclear Medicine and PET Research, VU University Medical Center, Amsterdam, The Netherlands.
J Nucl Med. 2010 Nov;51(11):1684-90. doi: 10.2967/jnumed.110.079137. Epub 2010 Oct 18.
Quantification of tumor perfusion using radioactive water (H(2)(15)O) and PET is a promising method for monitoring treatment with antiangiogenic agents. However, use of dynamic H(2)(15)O scans together with a fully 3-dimensional clinical PET/CT scanner needs to be validated. The purpose of the present study was to assess validity and reproducibility of dynamic H(2)(15)O PET/CT scans for measuring tumor perfusion and validate the quantitative accuracy of parametric perfusion images.
Eleven patients with non-small cell lung cancer were included in this study. Patients underwent 2 dynamic H(2)(15)O (370 MBq) PET scans on the same day. During the first scan, arterial blood was withdrawn continuously. Input functions were derived from blood sampler data and the ascending aorta as seen in the images themselves (image-derived input function [IDIF]). Parametric perfusion images were computed using a basis function implementation of the standard single-tissue-compartment model. Volumes of interest (VOIs) were delineated on low-dose CT (LD-CT) and parametric perfusion images.
VOIs could be accurately delineated on both LD-CT and parametric perfusion images. These parametric perfusion images had excellent image quality and quantitative accuracy when compared with perfusion values determined by nonlinear regression. Good correlation between perfusion values derived from the blood sampler input function and IDIF was found (Pearson correlation coefficient, r = 0.964; P < 0.001). Test-retest variability of tumor perfusion was 16% and 20% when delineated on LD-CT and parametric perfusion images, respectively.
The use of ascending aorta IDIFs is an accurate alternative to arterial blood sampling for quantification of tumor perfusion. Image quality obtained with a clinical PET/CT scanner enables generation of accurate parametric perfusion images. VOIs delineated on LD-CT have the highest reproducibility, and changes of more than 16% in tumor perfusion are likely to represent treatment effects.
使用放射性水（H(2)(15)O）和正电子发射断层扫描（PET）对肿瘤灌注进行定量是监测抗血管生成药物治疗的一种很有前途的方法。然而，需要验证使用动态 H(2)(15)O 扫描和全三维临床 PET/CT 扫描仪的方法。本研究的目的是评估动态 H(2)(15)O PET/CT 扫描测量肿瘤灌注的有效性和可重复性，并验证参数灌注图像的定量准确性。
本研究纳入了 11 名非小细胞肺癌患者。患者在同一天接受了 2 次动态 H(2)(15)O（370MBq）PET 扫描。在第一次扫描过程中，连续抽取动脉血。输入函数是通过血液取样器数据和图像中可见的升主动脉（图像衍生输入函数[IDIF]）得出的。使用标准单组织室模型的基函数实现计算参数灌注图像。在低剂量 CT（LD-CT）和参数灌注图像上勾画感兴趣区（VOI）。
可以在 LD-CT 和参数灌注图像上准确地勾画 VOI。与通过非线性回归确定的灌注值相比，这些参数灌注图像具有出色的图像质量和定量准确性。从血液取样器输入函数和 IDIF 得出的灌注值之间存在良好的相关性（Pearson 相关系数 r = 0.964；P <0.001）。当在 LD-CT 和参数灌注图像上勾画时，肿瘤灌注的测试-重测变异性分别为 16%和 20%。
使用升主动脉 IDIF 是定量肿瘤灌注的一种准确替代动脉采血的方法。临床 PET/CT 扫描仪获得的图像质量能够生成准确的参数灌注图像。在 LD-CT 上勾画的 VOI 具有最高的可重复性，肿瘤灌注的变化超过 16%可能代表治疗效果。
