Calibration Test of PET Scanners in a Multi-Centre Clinical Trial on Breast Cancer Therapy Monitoring Using 18F-FLT
Calibration Test of PET Scanners in a Multi-Centre Clinical Trial on Breast Cancer Therapy Monitoring Using 18F-FLT
复制标题
使用 18F-FLT 监测乳腺癌治疗的多中心临床试验中 PET 扫描仪的校准测试
作者：
F. Bouchet;L. Geworski;B. Knoop;L. Ferrer;Alina Barriolo;C. Millardet;M. Fourcade;A. Martineau;A. Belly;Francis Djoumessi;K. Tendero;Laurent Keros;Frederic Montoya;C. Mesleard;Anne;F. Lacoeuille;O. Couturier
使用PET的多中心试验需要分析在不同系统上获得的图像。我们设计了一项多中心试验，以评估18F-FLT-PET预测新诊断乳腺癌患者对新辅助化疗的反应的价值。对每个PET-CT及其外围设备进行校准检查，以评价结果的可靠性。材料与方法11个中心进行了调查。通过重复测量68 Ge认证源来评估剂量校准器。记录了与剂量校准器相关的时钟和PET系统固有时钟之间的差异。PET-CT的校准使用均匀圆柱体模进行评估，方法是将根据剂量校准器测量值计算的每单位体积放射性与在重建的滤波反投影（FBP）图像的15个连续切片上绘制的15个感兴趣区域（ROI）上测量的放射性进行比较。评价了基于15个ROI的活性浓度的重复性（ANOVA检验）及其准确度。结果剂量校准器测量结果无显著差异（差异中位数为−0.04%;最小值= −4.65%;最大值=+5.63%）。 在所有研究中心，时钟之间的不匹配均小于2 min，因此不需要对18 F的半衰期进行任何校正。对于所有PET系统，ANOVA显示，根据15个ROI估计的活性浓度之间无显著差异（差异中位数为-0.69%;最小值=-9.97%;最大值=+9.60%）。 结论11个中心之间在校准和交叉校准方面没有观察到重大差异。因此，从物理角度证实了我们的18F-FLT多中心临床试验的可靠性。这种类型的程序可能适用于涉及不同PET系统的任何临床试验。
A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results. Material and Methods 11 centres were investigated. Dose calibrators were assessed by repeated measurements of a 68Ge certified source. The differences between the clocks associated with the dose calibrators and inherent to the PET systems were registered. The calibration of PET-CT was assessed with an homogeneous cylindrical phantom by comparing the activities per unit of volume calculated from the dose calibrator measurements with that measured on 15 Regions of Interest (ROIs) drawn on 15 consecutive slices of reconstructed filtered back-projection (FBP) images. Both repeatability of activity concentration based upon the 15 ROIs (ANOVA-test) and its accuracy were evaluated. Results There was no significant difference for dose calibrator measurements (median of difference −0.04%; min = −4.65%; max = +5.63%). Mismatches between the clocks were less than 2 min in all sites and thus did not require any correction, regarding the half life of 18F. For all the PET systems, ANOVA revealed no significant difference between the activity concentrations estimated from the 15 ROIs (median of difference −0.69%; min = −9.97%; max = +9.60%). Conclusion No major difference between the 11 centres with respect to calibration and cross-calibration was observed. The reliability of our 18F-FLT multi-centre clinical trial was therefore confirmed from the physical point of view. This type of procedure may be useful for any clinical trial involving different PET systems.