Added value of 18F-FDG total-body PET/CT dynamic imaging in the diagnosis of liver malignant tumors / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore the added value of time-activity curve (TAC) and target-to-background ratio (TBR) obtained by 18F-FDG total-body PET/CT dynamic imaging in the diagnosis of liver malignant tumors. Methods:From December 2019 to October 2021, 109 patients (65 males, 44 females; age (59.3±9.3) years) with hepatocellular carcinoma (HCC; n=27), intrahepatic cholangiocarcinoma (ICC; n=61) and colorectal cancer with liver metastasis (CRLM; n=21) who underwent 60 min 18F-FDG total-body PET/CT dynamic imaging in Zhongshan Hospital, Fudan University were retrospectively enrolled. Dynamic PET/CT images were divided into perfusion-weighted (PW) phase and metabolism-weighted (MW) phase. The arterial phase was defined as the 15 s after the abdominal aorta peak frame at PW. TACs at MW were divided into three types as Graph A, Graph B and Graph C. One-way analysis of variance was used to compare difference of TBR 30/60 among groups. ROC curve analysis was used to evaluate diagnostic effectiveness. Results:With hypervascularity as the diagnostic standard of HCC, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 66.7%(18/27), 75.6%(59/78), 48.6%(18/37) and 86.8%(59/68), respectively. With Graph B as the diagnostic standard of HCC, the sensitivity, specificity, PPV and NPV were 44.4%(12/27), 85.4%(70/82), 50.0%(12/24) and 82.4%(70/85), respectively. The TBR 30/60 of HCC, ICC and CRLM was 0.38±0.19, 0.49±0.18 and 0.64±0.20 respectively ( F=10.89, P<0.001). When the cut-off value of TBR 30/60 was 0.43, the AUC of distinguishing HCC from ICC and CRLM was 0.72, with the sensitivity and specificity of 70.5%(55/78) and 65.2%(15/23). When the cut-off value of TBR 30/60 was 0.64, the AUC of distinguishing ICC from CRLM was 0.71, with the sensitivity and specificity of 61.9%(13/21) and 82.5%(47/57). Conclusion:TAC graph types and TBR 30/60 obtained by total-body PET/CT dynamic imaging display potential value for differentiation between hepatic tumor types.