目的:本研究旨在评估早期30分钟动态2-脱氧-2-[18F]氟-D-葡萄糖(18F-FDG)正电子发射断层扫描(PET)扫描方案的临床可行性与标准的65分钟动态FDG-PET扫描作为参考。
方法:在这项前瞻性研究中,分析了146例181个肺部病变(包括146个经组织学证实的病变)的动态18F-FDGPET图像。对于注射后65分钟采集的扫描数据,使用特定的时间划分协议将动态图像重建为28帧。通过使用内部Matlab软件应用不可逆的两组织区室模型,获得基于两个不同采集持续时间[前30分钟(Ki-30分钟)和65分钟(Ki-65分钟)]的Ki图像和定量参数Ki。比较两种采集持续时间的Ki图像质量(包括视觉评分分析和检测到的病变数量)和Ki值(包括Ki的准确性,通过Wilcoxon秩和检验对肺部病变的鉴别诊断和PD-L1状态的预测),斯皮尔曼等级相关分析,接收机工作特性(ROC)曲线,还有德隆测试.显著测试水平(α)设置为0.05。
结果:根据视觉评分分析,Ki-30min图像的质量与Ki-65min图像的质量无明显差异(P>0.05)。就Ki值而言,在181个病灶中,Ki-65min在统计学上高于Ki-30min(0.027±0.017ml/g/minvs.0.026±0.018ml/g/min,P<0.05),Ki-65min与Ki-30min有很高的相关性(r=0.977,P<0.05)。在肺部病变的鉴别诊断中,对146个组织学证实的病变进行ROC分析,Ki-65min的曲线下面积(AUC),Ki-30分钟,和SUVmax分别为0.816、0.816和0.709。根据德隆测试,Ki-65min和Ki-30min的诊断准确率差异无统计学意义(P>0.05),而Ki-65min和Ki-30min的诊断准确率均显著高于SUVmax(P<0.05)。在有明确PD-L1表达结果的73个(NSCLC)病变中,Ki-65分钟,Ki-30分钟,PD-L1阳性和SUVmax明显高于PD-L1阴性(P<0.05)。预测PD-L1阳性在Ki-65min之间没有发现显著差异,Ki-30分钟,和SUVmax(AUC分别为0.704、0.695和0.737,P>0.05),根据结果进行ROC分析和Delong检验。
结论:这项研究表明,早期30分钟动态FDG-PET采集似乎足以提供具有高质量和准确Ki值的定量图像,用于评估肺部病变和预测PD-L1表达。对于难以长时间采集的患者,可以考虑缩短早期30分钟采集时间的方案,以提高临床采集的效率。
OBJECTIVE: This study aimed to evaluate the clinical feasibility of early 30-minute dynamic 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) positron emission tomography (PET) scanning protocol for patients with lung lesions in comparison to the standard 65-minute dynamic FDG-PET scanning as a reference.
METHODS: Dynamic 18F-FDG PET images of 146 patients with 181 lung lesions (including 146 lesions confirmed by histology) were analyzed in this prospective study. Dynamic images were reconstructed into 28 frames with a specific temporal division protocol for the scan data acquired 65 min post-injection. Ki images and quantitative parameters Ki based on two different acquisition durations [the first 30 min (Ki-30 min) and 65 min (Ki-65 min)] were obtained by applying the irreversible two-tissue compartment model using in-house Matlab software. The two acquisition durations were compared for Ki image quality (including visual score analysis and number of lesions detected) and Ki value (including accuracy of Ki, the value of differential diagnosis of lung lesions and prediction of PD-L1 status) by Wilcoxon\'s rank sum test, Spearman\'s rank correlation analysis, receiver operating characteristic (ROC) curve, and the DeLong test. The significant testing level (alpha) was set to 0.05.
RESULTS: The quality of the Ki-30 min images was not significantly different from the Ki-65 min images based on visual score analysis (P > 0.05). In terms of Ki value, among 181 lesions, Ki-65 min was statistically higher than Ki-30 min (0.027 ± 0.017 ml/g/min vs. 0.026 ± 0.018 ml/g/min, P < 0.05), while a very high correlation was obtained between Ki-65 min and Ki-30 min (r = 0.977, P < 0.05). In the differential diagnosis of lung lesions, ROC analysis was performed on 146 histologically confirmed lesions, the area under the curve (AUC) of Ki-65 min, Ki-30 min, and SUVmax was 0.816, 0.816, and 0.709, respectively. According to the Delong test, no significant differences in the diagnostic accuracies were found between Ki-65 min and Ki-30 min (P > 0.05), while the diagnostic accuracies of Ki-65 min and Ki-30 min were both significantly higher than that of SUVmax (P < 0.05). In 73 (NSCLC) lesions with definite PD-L1 expression results, the Ki-65 min, Ki-30 min, and SUVmax in PD-L1 positivity were significantly higher than that in PD-L1 negativity (P < 0.05). And no significant differences in predicting PD-L1 positivity were found among Ki-65 min, Ki-30 min, and SUVmax (AUC = 0.704, 0.695, and 0.737, respectively, P > 0.05), according to the results of ROC analysis and Delong test.
CONCLUSIONS: This study indicates that an early 30-minute dynamic FDG-PET acquisition appears to be sufficient to provide quantitative images with good-quality and accurate Ki values for the assessment of lung lesions and prediction of PD-L1 expression. Protocols with a shortened early 30-minute acquisition time may be considered for patients who have difficulty with prolonged acquisitions to improve the efficiency of clinical acquisitions.