Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands; and
Department of Pulmonary Diseases, VU University Medical Center, Amsterdam, The Netherlands.
J Nucl Med. 2014 Nov;55(11):1772-7. doi: 10.2967/jnumed.114.141846. Epub 2014 Oct 16.
(18)F-fluoroazomycinarabinoside ((18)F-FAZA) is a hypoxia-specific PET tracer. In future clinical applications of hypoxia imaging, such as early response monitoring or radiation therapy dose painting, accurate quantification of tracer uptake at the voxel level will be required. The aim of the present study was to assess the validity of parametric methods for the quantification of (18)F-FAZA studies.
Dynamic 70-min (18)F-FAZA scans were obtained from 9 non-small cell lung cancer patients. Arterial blood samples, collected at 7 time points, were used for preprocessing an image-derived input function derived from volumes of interest (VOIs) defined within the ascending aorta. Time-activity curves derived from various tumor VOIs were fitted using nonlinear regression analysis (NLR) to a reversible 2-tissue-compartment model, providing volumes of distribution (V(T)) as an outcome measure. Next, parametric images were generated by use of both Logan graphic analysis with various linear regression start times and spectral analysis with multiple sets of basis functions. The previously defined tumor VOIs were projected onto these parametric images, and the resulting V(T) were compared with those obtained from NLR. In addition, the results were compared with tumor-to-blood ratios (SUVr), which are more easily obtainable.
The highest correlations and correspondence with NLR-derived V(T) were found for Logan graphic analysis with a start time of 30 min after injection (R(2), 0.88; intraclass correlation coefficient [ICC], 0.93) and for spectral analysis-derived V(T) with a set of 30 basis functions with exponents ranging from 0.0175 to 1.9 (R(2), 0.79; ICC, 0.81). SUVr yielded similar correlations but showed significant bias at high V(T) (R(2), 0.85; ICC, 0.80).
Both Logan graphic analysis and spectral analysis yielded V(T) that showed high correlations with nonlinear regression analysis-derived V(T). SUVr showed bias at high V(T).
（18）F-氟代氮杂胞苷（（18）F-FAZA）是一种缺氧特异性 PET 示踪剂。在未来的缺氧成像临床应用中，例如早期反应监测或放射治疗剂量绘画，需要在体素水平上准确量化示踪剂摄取。本研究的目的是评估用于量化（18）F-FAZA 研究的参数方法的有效性。
从 9 名非小细胞肺癌患者中获得 70 分钟的动态（18）F-FAZA 扫描。采集的 7 个时间点的动脉血样用于预处理通过感兴趣区（VOI）定义的升主动脉内的图像衍生输入函数。使用非线性回归分析（NLR）对从各种肿瘤 VOI 获得的时间活动曲线进行拟合，提供分布体积（V（T））作为结果测量。接下来，使用 Logan 图形分析和多个线性回归起始时间以及具有多个基函数集的谱分析生成参数图像。将先前定义的肿瘤 VOI 投射到这些参数图像上，并将得到的 V（T）与 NLR 得到的 V（T）进行比较。此外，将结果与肿瘤与血液的比值（SUVr）进行比较，后者更容易获得。
与 NLR 衍生的 V（T）相关性最高和一致性最好的是注射后 30 分钟开始的 Logan 图形分析（R（2），0.88；组内相关系数[ICC]，0.93）和光谱分析衍生的 V（T）具有一组 30 个指数从 0.0175 到 1.9 的基函数（R（2），0.79；ICC，0.81）。SUVr 产生了类似的相关性，但在高 V（T）时显示出明显的偏差（R（2），0.85；ICC，0.80）。
Logan 图形分析和光谱分析都产生了与非线性回归分析衍生的 V（T）高度相关的 V（T）。SUVr 在高 V（T）时存在偏差。
