Kim M Pabst, Lukas Kessler, Justin Ferdinandus, Rainer Hamacher, Timo Bartel, Jens T Siveke, Michael Nader, Tim Brandenburg, Mélanie Desaulniers, Ken Herrmann, Wolfgang P Fendler
{"title":"[<sup>68</sup>Ga]Ga-FAPI versus 2-[<sup>18</sup>F]FDG PET/CT in patients with autoimmune thyroiditis: a case control study.","authors":"Kim M Pabst, Lukas Kessler, Justin Ferdinandus, Rainer Hamacher, Timo Bartel, Jens T Siveke, Michael Nader, Tim Brandenburg, Mélanie Desaulniers, Ken Herrmann, Wolfgang P Fendler","doi":"10.1186/s13550-024-01129-y","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Radiolabelled fibroblast activation protein inhibitors (FAPIs) are becoming increasingly important for imaging various tumour diseases. However, it is essential to be aware of potential pitfalls. Here, we investigate FAP expression in the thyroid gland in autoimmune thyroiditis (AIT).</p><p><strong>Methods: </strong>AIT patients with pathological thyroid uptake on [<sup>68</sup>Ga]Ga-FAPI PET were compared with glucose metabolism on 2-[<sup>18</sup>F]FDG PET in terms of SUV<sub>max</sub>/SUV<sub>peak</sub>/SUV<sub>mean</sub>/tissue-to-background ratio (TBR), and with a healthy control group.</p><p><strong>Results: </strong>Between September 2019 and July 2021, 6 patients presented with a visually increased thyroid uptake and TBR on [<sup>68</sup>Ga]Ga-FAPI PET. In the retrospective clinical work-up, all patients had known or newly diagnosed AIT. Compared to a matched healthy control group, FAP expression and glucose metabolism were significantly increased ([<sup>68</sup>Ga]Ga-FAPI (SUV<sub>peak</sub>): 7.0 vs. 1.7; p = 0.004/(TBR<sub>bloodpool</sub>): 6.8 vs. 1.7; p = 0.002; 2-[<sup>18</sup>F]FDG (SUV<sub>peak</sub>): 3.9 vs. 1.4; p = 0.004/(TBR<sub>bloodpool</sub>): 4.0 vs. 1.2; p = 0.041). However, there was no significant difference in median uptake between [<sup>68</sup>Ga]Ga-FAPI and 2-[18F]FDG PET (SUV<sub>peak</sub>: 7.3 vs. 5.6; p = 0.104).</p><p><strong>Conclusion: </strong>Patients with AIT show higher thyroid uptake on [<sup>68</sup>Ga]Ga-FAPI and 2-[<sup>18</sup>F]FDG PET. Incidental thyroid uptake is another pitfall in the interpretation of [<sup>68</sup>Ga]Ga-FAPI PET and should prompt a clinical work-up.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11258103/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Applied Electronic Materials","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s13550-024-01129-y","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: Radiolabelled fibroblast activation protein inhibitors (FAPIs) are becoming increasingly important for imaging various tumour diseases. However, it is essential to be aware of potential pitfalls. Here, we investigate FAP expression in the thyroid gland in autoimmune thyroiditis (AIT).
Methods: AIT patients with pathological thyroid uptake on [68Ga]Ga-FAPI PET were compared with glucose metabolism on 2-[18F]FDG PET in terms of SUVmax/SUVpeak/SUVmean/tissue-to-background ratio (TBR), and with a healthy control group.
Results: Between September 2019 and July 2021, 6 patients presented with a visually increased thyroid uptake and TBR on [68Ga]Ga-FAPI PET. In the retrospective clinical work-up, all patients had known or newly diagnosed AIT. Compared to a matched healthy control group, FAP expression and glucose metabolism were significantly increased ([68Ga]Ga-FAPI (SUVpeak): 7.0 vs. 1.7; p = 0.004/(TBRbloodpool): 6.8 vs. 1.7; p = 0.002; 2-[18F]FDG (SUVpeak): 3.9 vs. 1.4; p = 0.004/(TBRbloodpool): 4.0 vs. 1.2; p = 0.041). However, there was no significant difference in median uptake between [68Ga]Ga-FAPI and 2-[18F]FDG PET (SUVpeak: 7.3 vs. 5.6; p = 0.104).
Conclusion: Patients with AIT show higher thyroid uptake on [68Ga]Ga-FAPI and 2-[18F]FDG PET. Incidental thyroid uptake is another pitfall in the interpretation of [68Ga]Ga-FAPI PET and should prompt a clinical work-up.
目的:放射性标记成纤维细胞活化蛋白抑制剂(FAPIs)对各种肿瘤疾病的成像越来越重要。然而,必须注意潜在的隐患。在此,我们研究了自身免疫性甲状腺炎(AIT)甲状腺中FAP的表达:方法:将[68Ga]Ga-FAPI PET上病理甲状腺摄取的AIT患者与2-[18F]FDG PET上葡萄糖代谢的SUVmax/SUVpeak/SUVmean/组织与背景比值(TBR)进行比较,并与健康对照组进行比较:2019年9月至2021年7月期间,6名患者出现[68Ga]Ga-FAPI PET甲状腺摄取和TBR明显增高。在回顾性临床检查中,所有患者均为已知或新诊断的 AIT 患者。与匹配的健康对照组相比,FAP表达和葡萄糖代谢显著增加([68Ga]Ga-FAPI (SUVpeak):7.0 vs. 1.7; p = 0.004/(TBRbloodpool):6.8 vs. 1.7; p = 0.002; 2-[18F]FDG (SUVpeak):3.9 vs. 1.4; p = 0.004/(TBRbloodpool):4.0 vs. 1.2; p = 0.041)。然而,[68Ga]Ga-FAPI和2-[18F]FDG PET的中位摄取量没有明显差异(SUVpeak:7.3 vs. 5.6;p = 0.104):结论:AIT患者在[68Ga]Ga-FAPI和2-[18F]FDG PET上表现出较高的甲状腺摄取。甲状腺意外摄取是解读[68Ga]Ga-FAPI PET的另一个陷阱,应及时进行临床检查。