From the Department of Nuclear Medicine, University Hospital Würzburg, Würzburg.
Nuclear Medicine, Medical Faculty, University Hospital Augsburg, Augsburg, Germany.
Clin Nucl Med. 2023 Jun 1;48(6):483-488. doi: 10.1097/RLU.0000000000004629. Epub 2023 Mar 22.
We aimed to evaluate the interobserver agreement rates in patients scanned with C-X-C motif chemokine receptor 4 (CXCR4)-directed PET/CT, including the rate of patients eligible for CXCR4-targeted radioligand therapy (RLT) based on scan results.
Four independent observers reviewed 50 CXCR4-targeted [ 68 Ga]pentixafor PET/CT of patients with various solid cancers. On a visual level, the following items were assessed by each reader: overall scan impression, number of organ and lymph node (LN) metastases and number of affected organs and LN regions. For a quantitative investigation, readers had to choose a maximum of 3 target lesions, defined as largest in size and/or most intense uptake per organ compartment. Reference tissues were also quantified, including unaffected hepatic parenchyma and blood pool. Last, all observers had to decide whether patients were eligible for CXCR4-targeted RLT. Concordance rates were tested using intraclass correlation coefficients (ICCs). For interpretation, we applied the definition of Cicchetti (with 0.4-0.59 indicating fair; 0.6-0.74, good; 0.75-1, excellent agreement).
On a visual level, fair agreement was achieved for an overall scan impression (ICC, 0.58; 95% confidence interval, 0.45-0.71). Organ and LN involvement (ICC, ≥0.4) demonstrated fair, whereas CXCR4 density and number of LN and organ metastases showed good agreement rates (ICC, ≥0.65). Number of affected organs and affected LN areas, however, showed excellent concordance (ICC, ≥0.76). Quantification in LN and organ lesions also provided excellent agreement rates (ICC, ≥0.92), whereas quantified uptake in reference organs provided fair concordance (ICC, ≥0.54). Again, excellent agreement rates were observed when deciding on patients eligible for CXCR4-RLT (ICC, 0.91; 95% confidence interval, 0.85-0.95).
In patients scanned with CXCR4-targeted PET/CT, we observed fair to excellent agreement rates for both molecular imaging and therapy parameters, thereby favoring a more widespread adoption of [ 68 Ga]pentixafor in the clinic.
我们旨在评估接受 C-X-C 基序趋化因子受体 4（CXCR4）靶向 PET/CT 扫描的患者的观察者间一致性率，包括根据扫描结果确定适合 CXCR4 靶向放射性配体治疗（RLT）的患者比例。
四位独立观察者评估了 50 例接受各种实体瘤 CXCR4 靶向[68Ga]戊基托啡的 PET/CT 扫描的患者。每位观察者从视觉上评估以下项目：整体扫描印象、器官和淋巴结（LN）转移的数量以及受影响的器官和 LN 区域的数量。为了进行定量研究，读者必须从每个器官隔室中选择最大的 3 个靶病变，这些病变按大小和/或摄取的最大强度来定义。还对参考组织进行了量化，包括未受影响的肝实质和血池。最后，所有观察者都必须决定患者是否适合接受 CXCR4 靶向 RLT。一致性率通过组内相关系数（ICC）进行检验。对于解释，我们应用 Cicchetti 的定义（0.4-0.59 表示一般；0.6-0.74，良好；0.75-1，极好的一致性）。
在视觉水平上，整体扫描印象的一致性为一般（ICC，0.58；95%置信区间，0.45-0.71）。器官和 LN 受累（ICC，≥0.4）的一致性为一般，而 CXCR4 密度和 LN 和器官转移的数量则显示出良好的一致性率（ICC，≥0.65）。然而，受影响的器官和受影响的 LN 区域的数量具有极好的一致性（ICC，≥0.76）。LN 和器官病变的量化也提供了极好的一致性率（ICC，≥0.92），而参考器官的摄取量则具有一般的一致性（ICC，≥0.54）。再次，当决定适合 CXCR4-RLT 的患者时，观察到极好的一致性率（ICC，0.91；95%置信区间，0.85-0.95）。
在接受 CXCR4 靶向 PET/CT 扫描的患者中，我们观察到分子成像和治疗参数的一致性率从一般到极好，从而支持[68Ga]戊基托啡在临床中的更广泛应用。
