AUTHOR=Wang Hao , Zhu Wenwei , Ren Shuhua , Kong Yanyan , Huang Qi , Zhao Jun , Guan Yihui , Jia Huliang , Chen Jinhong , Lu Lu , Xie Fang , Qin Lunxiu 

TITLE=68Ga-FAPI-04 Versus 18F-FDG PET/CT in the Detection of Hepatocellular Carcinoma

JOURNAL=Frontiers in Oncology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2021.693640

DOI=10.3389/fonc.2021.693640

ISSN=2234-943X

ABSTRACT=<sec><title>Background</title><p>Fibroblast activation protein (FAP) is commonly expressed in activated stromal fibroblasts in various epithelial tumours. Recently, <sup>68</sup>Ga-FAPI-04 has been used for tumour imaging in positron emission tomography/computed tomography (PET/CT). This study aimed to compare the diagnostic performances of <sup>68</sup>Ga-FAPI-04 PET/CT and <sup>18</sup>F-FDG PET/CT in hepatocellular carcinoma (HCC), and to assess factors associated with <sup>68</sup>Ga-FAPI-04 uptake in HCC.</p></sec><sec><title>Materials and Methods</title><p>Twenty-nine patients with suspiciously HCC who received both <sup>18</sup>F-FDG and <sup>68</sup>Ga-FAPI-04 PET/CT were included in this retrospective study. The results were interpreted by two experienced nuclear medicine physicians independently. The maximum and mean standardized uptake values (SUV<sub>max</sub> and SUV<sub>mean</sub>) were measured in the lesions and liver background, respectively. The tumour-to-background ratio (TBR) was then calculated as lesion’s SUV<sub>max</sub> divided by background SUV<sub>mean</sub>.</p></sec><sec><title>Results</title><p>A total of 35 intrahepatic lesions in 25 patients with HCC were finally involved in the statistical analysis. <sup>68</sup>Ga-FAPI-04 PET/CT showed a higher sensitivity than <sup>18</sup>F-FDG PET/CT in detecting intrahepatic HCC lesions (85.7% <italic>vs</italic>. 57.1%, <italic>P</italic> = 0.002), including in small (≤ 2 cm in diameter; 68.8% <italic>vs</italic>. 18.8%, <italic>P</italic> = 0.008) and well- or moderately-differentiated (83.3% <italic>vs</italic>. 33.3%, <italic>P</italic> = 0.031) tumors. SUV<sub>max</sub> was comparable between <sup>68</sup>Ga-FAPI-04 and <sup>18</sup>F-FDG (6.96 ± 5.01 <italic>vs</italic>. 5.89 ± 3.38, <italic>P</italic> &gt; 0.05), but the TBR was significantly higher in the <sup>68</sup>Ga-FAPI-04 group compared with the <sup>18</sup>F-FDG group (11.90 ± 8.35 <italic>vs</italic>. 3.14 ± 1.59, <italic>P</italic> &lt; 0.001). SUV<sub>max</sub> and the TBR in <sup>68</sup>Ga-FAPI-04 positive lesions were associated with tumour size (both <italic>P</italic> &lt; 0.05), but not the remaining clinical and pathological features (all <italic>P</italic> &gt; 0.05).</p></sec><sec><title>Conclusions</title><p><sup>68</sup>Ga-FAPI-04 PET/CT is more sensitive than <sup>18</sup>F-FDG PET/CT in detecting HCC lesions, and <sup>68</sup>Ga-FAPI-04 uptake is correlated mainly with tumour size.</p></sec>