Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany.
Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
Eur J Nucl Med Mol Imaging. 2023 Aug;50(10):3011-3021. doi: 10.1007/s00259-023-06245-w. Epub 2023 May 6.
We aimed to assess prevalence, distribution, and intensity of in-vivo arterial wall fibroblast activation protein (FAP) uptake, and its association with calcified plaque burden, cardiovascular risk factors (CVRFs), and FAP-avid tumor burden.
We analyzed 69 oncologic patients who underwent [ Ga]Ga-FAPI-04 PET/CT. Arterial wall FAP inhibitor (FAPI) uptake in major vessel segments was evaluated. We then investigated the associations of arterial wall uptake with calcified plaque burden (including number of plaques, plaque thickness, and calcification circumference), CVRFs, FAP-positive total tumor burden, and image noise (coefficient of variation, from normal liver parenchyma).
High focal arterial FAPI uptake (FAPI +) was recorded in 64/69 (92.8%) scans in 800 sites, of which 377 (47.1%) exhibited concordant vessel wall calcification. The number of FAPI + sites per patient and (FAPI +)-derived target-to-background ratio (TBR) correlated significantly with the number of calcified plaques (FAPI + number: r = 0.45, P < 0.01; TBR: r = - 0.26, P = 0.04), calcified plaque thickness (FAPI + number: r = 0.33, P < 0.01; TBR: r = - 0.29, P = 0.02), and calcification circumference (FAPI + number: r = 0.34, P < 0.01; TBR: r = - 0.26, P = 0.04). In univariate analysis, only body mass index was significantly associated with the number of FAPI + sites (OR 1.06; 95% CI, 1.02 - 1.12, P < 0.01). The numbers of FAPI + sites and FAPI + TBR, however, were not associated with other investigated CVRFs in univariate and multivariate regression analyses. Image noise, however, showed significant correlations with FAPI + TBR (r = 0.30) and the number of FAPI + sites (r = 0.28; P = 0.02, respectively). In addition, there was no significant interaction between FAP-positive tumor burden and arterial wall FAPI uptake (P ≥ 0.13).
[ Ga]Ga-FAPI-04 PET identifies arterial wall lesions and is linked to marked calcification and overall calcified plaque burden, but is not consistently associated with cardiovascular risk. Apparent wall uptake may be partially explained by image noise.
我们旨在评估体内动脉壁成纤维细胞激活蛋白（FAP）摄取的患病率、分布和强度，及其与钙化斑块负担、心血管危险因素（CVRF）和 FAP 阳性肿瘤负担的相关性。
我们分析了 69 名接受 [^68^Ga]Ga-FAPI-04 PET/CT 检查的肿瘤患者。评估了主要血管段的动脉壁 FAPI 抑制剂（FAPI）摄取情况。然后，我们研究了动脉壁摄取与钙化斑块负担（包括斑块数量、斑块厚度和钙化周长）、CVRF、FAP 阳性总肿瘤负担以及图像噪声（来自正常肝实质的变异系数）之间的关系。
在 800 个部位的 69 次扫描中，有 64 次（92.8%）记录到高焦点动脉 FAPI 摄取（FAPI+），其中 377 次（47.1%）显示出一致的血管壁钙化。每位患者的 FAPI+部位数量和（FAPI+）衍生的靶与背景比（TBR）与钙化斑块数量显著相关（FAPI+数量：r=0.45，P<0.01；TBR：r=−0.26，P=0.04）、钙化斑块厚度（FAPI+数量：r=0.33，P<0.01；TBR：r=−0.29，P=0.02）和钙化周长（FAPI+数量：r=0.34，P<0.01；TBR：r=−0.26，P=0.04）。在单变量分析中，只有体重指数与 FAPI+部位数量显著相关（OR 1.06；95%CI，1.02-1.12，P<0.01）。然而，在单变量和多变量回归分析中，FAPI+部位数量和 FAPI+TBR 与其他研究的 CVRF 之间无相关性。然而，图像噪声与 FAPI+TBR（r=0.30）和 FAPI+部位数量（r=0.28；P=0.02）呈显著相关性。此外，FAP 阳性肿瘤负担与动脉壁 FAPI 摄取之间没有显著的相互作用（P≥0.13）。
[^68^Ga]Ga-FAPI-04 PET 可识别动脉壁病变，并与明显的钙化和总钙化斑块负担相关，但与心血管风险无一致相关性。明显的壁摄取可能部分由图像噪声解释。
