The aim of this study was to assess the interobserver variability of quantitative ¹⁸F-FDG PET/CT parameters used in assessments of treatment response across multiple sites and readers. Methods: Paired pre- and posttreatment ¹⁸F-FDG PET/CT images of 30 oncologic patients were distributed to 22 readers across 15 U.S. and international sites. One reader was aware of the full medical history (read_reference) of the patients, whereas the 21 other readers were unaware. The readers selected the single hottest tumor from each study, and made SUV measurements from this target lesion and the liver. Descriptive statistics, percentage changes in the measurements, and their agreements were obtained. Results: The intraclass correlation coefficient for the percentage change in SUV_max (%ΔSUV_max) of the hottest tumor was 0.894 (95% confidence interval [CI], 0.813–0.941), and the individual equivalence coefficient was 1.931 (95% CI, 0.568–6.449) when all reads were included (n = 638). When only the measurements that selected the same target tumor as the read_reference (n = 486) were included, the intraclass correlation coefficient for the %ΔSUV_max was 0.944 (95% CI, 0.841–0.989), and the individual equivalence coefficient was −0.688 (95% CI, −1.810 to −0.092). The absolute change in SUV_mean of liver corrected for lean body mass showed upper and lower limits of agreement (average bias ± 2 SDs) of 0.13 and −0.13 g/mL. Conclusion: The quantitative tumor SUV changes measured across multiple sites and readers show a high correlation. Selection of the same tumor target among readers further increased the degree of correlation.

这项研究的目的是评估用于评估多个部位和读者的治疗反应的定量¹⁸ F-FDG PET / CT参数在观察者之间的变异性。方法：将治疗前后的30例肿瘤患者的^18张F-FDG PET / CT图像配对分发给美国和国际15个站点的22位读者。一位读者知道患者的完整病史（阅读_参考资料），而其他21位读者则不知道。读者从每个研究中选择了最热的单个肿瘤，并从该目标病变和肝脏进行了SUV测量。获得了描述性统计数据，度量值的百分比变化及其一致性。结果：用于SUV的百分比变化的组内相关系数_最大值（％ΔSUV_最大最热肿瘤的）为0.894（95％置信区间[CI]，0.813-0.941），和单独的等价系数为1.931（95％CI，0.568- 6.449）（包括所有读取）（n = 638）。当仅测量所选择的相同的靶肿瘤作为读取_参考（Ñ = 486）都包括在内，对于％内相关系数ΔSUV_最大值是0.944（95％CI，0.841-0.989），和单独的等价系数为- 0.688（95％CI，-1.810至-0.092）。SUV的绝对变化_均值校正了瘦体重的肝脏样本显示出一致的上限和下限（平均偏差±2 SDs）为0.13和-0.13 g / mL。结论：跨多个站点测量的定量肿瘤SUV变化与读者显示出高度相关性。在读者中选择相同的肿瘤靶标进一步提高了相关程度。