PET Imaging of Fibroblast Activation Protein in Various Types of Cancer Using 68Ga-FAP-2286: Comparison with 18F-FDG and 68Ga-FAPI-46 in a Single-Center, Prospective Study
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PET imaging that targets fibroblast activation protein (FAP) on the surface of cancer-associated fibroblasts has yielded promising tumor diagnostic results. FAP-2286 contains cyclic peptides as FAP-binding motifs to optimize tumor retention compared with the small-molecule FAP inhibitor (FAPI) series (FAPI-04/46). The aim of this study was to evaluate the diagnostic accuracy of 68Ga-FAP-2286 to detect primary and metastatic lesions in patients with various types of cancer, compared with 18F-FDG and 68Ga-FAP-2286. Methods: Sixty-four patients with 15 types of cancer underwent 68Ga-FAP-2286 PET/CT for initial assessment or detection of recurrence. For comparison, 63 patients underwent paired 68Ga-FAP-2286 and 18F-FDG PET/CT and 19 patients underwent paired 68Ga-FAP-2286 and 68Ga-FAPI-46 PET/CT. Lesion uptake was quantified as SUVmax and tumor-to-background ratio. The Wilcoxon matched-pairs signed-rank test was used to compare SUVmax between PET modalities, and the McNemar test was used to compare lesion detectability. Results: Uptake of 68Ga-FAP-2286 was significantly higher than that of 18F-FDG in primary tumors (median SUVmax, 11.1 vs. 6.9; P < 0.001), lymph node metastases (median SUVmax, 10.6 vs. 6.2; P < 0.001), and distant metastases, resulting in improved image contrast and lesion detectability. All primary tumors (46/46) were clearly visualized by 68Ga-FAP-2286 PET/CT, whereas 9 of the 46 lesions could not be visualized by 18F-FDG PET/CT. The lesion detection rate of 68Ga-FAP-2286 PET/CT was superior to that of 18F-FDG PET/CT for involved lymph nodes (98% [105/107] vs. 85% [91/107], P = 0.001) and bone and visceral metastases (95% [162/171] vs. 67% [114/171], P < 0.001). 68Ga-FAP-2286 yielded tumor uptake and lesion detection rates similar to those of 68Ga-FAPI-46 in a subcohort of 19 patients. Conclusion: 68Ga-FAP-2286 is a promising FAP-inhibitor derivative for safe cancer diagnosis, staging, and restaging. It may be a better alternative to 18F-FDG for the cancer types that exhibit low-to-moderate uptake of 18F-FDG, which include gastric, pancreatic, and hepatic cancers. In addition, 68Ga-FAP-2286 and 68Ga-FAPI-46 yielded comparable clinical results.
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Fibroblast-Activation Protein PET and Histopathology in a Single
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FAPI PET: Fibroblast Activation Protein Inhibitor Use in Oncologic
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Eight patients with pancreatic cancer underwent ¹⁸F-FDG and
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FAP-targeted PET imaging in gastrointestinal malignancies: a
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Eight representative patients with pancreatic cancer underwent
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PDF] Radiation Dosimetry and Biodistribution of 68Ga-FAPI-46 PET
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Comparison of 68Ga-FAPI and 18F-FDG Uptake in Gastric, Duodenal
![](https://www.researchgate.net/publication/353855039/figure/fig1/AS:1157125963292672@1652891736974/Pretreatment-68-Ga-FAPI-46-PET-images-and-posttreatment-90-Y-FAPI-46-bremsstrahlung.png)
Pretreatment 68 Ga-FAPI-46 PET images and posttreatment 90 Y-FAPI
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Frontiers FAPI PET/CT in the Diagnosis of Abdominal and Pelvic
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The Added Value of 68Ga-FAPI PET/CT in Patients with Head and Neck
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Translational imaging of the fibroblast activation protein (FAP
![](https://pubs.rsna.org/cms/10.1148/radiol.2020203275/asset/images/medium/radiol.2020203275.va.gif)
Comparison of 68Ga-FAPI and 18F-FDG Uptake in Gastric, Duodenal
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Translational imaging of the fibroblast activation protein (FAP