⁶⁸Ga-FAPI PET/CT: Tracer Uptake in 28 Different Kinds of Cancer

Abstract

The recent development of quinoline-based PET tracers that act as fibroblast-activation-protein inhibitors (FAPIs) demonstrated promising preclinical and clinical results. FAP is overexpressed by cancer-associated fibroblasts of several tumor entities. Here, we quantify the tumor uptake on 68 Ga-FAPI PET/CT of various primary and metastatic tumors to identify the most promising indications for future application. Methods: 68 Ga-FAPI PET/CT scans were requested by various referring physicians according to individual clinical indications that were considered insufficiently covered by 18 F-FDG PET/CT or other imaging modalities. All PET/CT was performed 1 h after injection of 122-312 MBq of 68 Ga-FAPI-04. We retrospectively identified 80 patients with histopathologically proven primary tumors or metastases or radiologically unequivocal metastatic lesions of histologically proven primary tumors. Tumor uptake was quantified by SUV max and SUV mean (60% isocontour). Results: Eighty patients with 28 different tumor entities (54 primary tumors and 229 metastases) were evaluated. The highest average SUV max (.12) was found in sarcoma, esophageal, breast, cholangiocarcinoma, and lung cancer. The lowest 68 Ga-FAPI uptake (average SUV max , 6) was observed in pheochromocytoma, renal cell, differentiated thyroid, adenoid cystic, and gastric cancer. The average SUV max of hepatocellular, colorectal, head-neck, ovarian, pancreatic, and prostate cancer was intermediate . SUV varied across and within all tumor entities. Because of low background in muscle and blood pool (SUV max , 2), the tumor-to-background contrast ratios were more than 3-fold in the intermediate and more than 6fold in the high-intensity uptake group. Conclusion: Several highly prevalent cancers presented with remarkably high uptake and image contrast on 68 Ga-FAPI PET/CT. The high and rather selective tumor uptake may open up new applications for noninvasive tumor characterization, staging examinations, or radioligand therapy. ://jnm.snmjournals.org/content/60/6/801 This article and updated information are available at: http://jnm.snmjournals.org/site/subscriptions/online.xhtml Information about subscriptions to JNM can be found at: http://jnm.snmjournals.org/site/misc/permission.xhtml

Radiolabelled Peptides for Positron Emission Tomography and Endoradiotherapy in Oncology

“…Recently, fibroblast activation protein inhibitors (FAPI) have become a focus of interest because this transmembrane serine protease is involved in the development of a great variety of tumour types [257] and initial clinical studies have demonstrated very promising results with high tumour uptake and good tumour/background ratios [258]. Most of the studied 68 Ga-labelled radiopharmaceuticals are based on a Gly-Pro unit, which is found to be a binding motive of this protease.…”

Präzisionsonkologie revolutioniert Nuklearmedizin mit theranostischem Ansatz

“…Bauchspeicheldrüsen-, Darm-und Brustkrebs gehören [10]. Mit 68 Ga markiertem FAPI war es möglich, 28 verschiedene Tumorarten mittels PET darzustellen [11]. Und auch mit FAPI bietet sich die Möglichkeit der Theranostik mit 90 Y-FAPI-04.…”

Cyclotron-based production of 68Ga, [68Ga]GaCl3, and [68Ga]Ga-PSMA-11 from a liquid target

“…In the United States, DOTATATE labeled with 68 Ga (NETSPOT) and 177 Lu (Lutathera) by the U.S. Food and Drug Administration for NET diagnosis and therapy while, the European Union approved [ 68 Ga]DOTATOC (SomaKIT TOC) and Lutathera. Subsequent development of theranostic agents for infection/in ammation (Velikyan 2018), prostate cancer (Eder et al 2014;Lenzo et al 2018;Ruangma et al 2018), C-X-C chemokine receptor type 4 (CXCR4) (Gourni et al 2011;Herrmann et al 2016) and, most recently, broblast activation protein inhibitors (FAPI) (Kratochwil et al 2019) is further driving demand and highlights the need for access to a reliable (and economical) supply of gallium-68 that is the focus of this paper. Analogous development of a reliable pipeline of therapeutic radionuclides is also an urgent need for the nuclear medicine community (Herrmann et al 2020), but beyond the scope of this article.…”