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Kiani M, Jokar S, Hassanzadeh L, Behnammanesh H, Bavi O, Beiki D, Assadi M. Recent Clinical Implications of FAPI: Imaging and Therapy. Clin Nucl Med 2024:00003072-990000000-01220. [PMID: 39025634 DOI: 10.1097/rlu.0000000000005348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
ABSTRACT The fibroblast activation protein (FAP) is a biomarker that is selectively overexpressed on cancer-associated fibroblasts (CAFs) in various types of tumoral tissues and some nonmalignant diseases, including fibrosis, arthritis, cardiovascular, and metabolic diseases. FAP plays a critical role in tumor microenvironment through facilitating proliferation, invasion, angiogenesis, immunosuppression, and drug resistance. Recent studies reveal that FAP might be regarded as a promising target for cancer diagnosis and treatment. FAP-targeted imaging modalities, especially PET, have shown high sensitivity and specificity in detecting FAP-expressing tumors. FAP-targeted imaging can potentially enhance tumor detection, staging, and monitoring of treatment response, and facilitate the development of personalized treatment strategies. This study provides a comprehensive view of FAP and its function in the pathophysiology of cancer and nonmalignant diseases. It also will discuss the characteristics of radiolabeled FAP inhibitors, particularly those based on small molecules, their recent clinical implications in imaging and therapy, and the associated clinical challenges with them. In addition, we present the results of imaging and biodistribution radiotracer 68Ga-FAPI-46 in patients with nonmalignant diseases, including interstitial lung disease, primary biliary cirrhosis, and myocardial infarction, who were referred to our department. Our results show that cardiac FAP-targeted imaging can provide a novel potential biomarker for managing left ventricle remodeling. Moreover, this study has been organized and presented in a manner that offers a comprehensive overview of the current status and prospects of FAPI inhibitors in the diagnosis and treatment of diseases.
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Affiliation(s)
- Mahshid Kiani
- From the Department of Nuclear Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Safura Jokar
- From the Department of Nuclear Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Leila Hassanzadeh
- Department of Nuclear Medicine, School of Medicine, Rajaie Cardiovascular, Medical & Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Omid Bavi
- Department of Mechanical Engineering, Shiraz University of Technology, Shiraz, Iran
| | - Davood Beiki
- Research Center for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Majid Assadi
- The Persian Gulf Nuclear Medicine Research Center, Department of Molecular Imaging and Radionuclide Therapy, Bushehr Medical University Hospital, Bushehr University of Medical Sciences, Bushehr, Iran
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2
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Nakayama M, Hope TA, Salavati A. Diagnostic and Therapeutic Application of Fibroblast Activation Protein Inhibitors in Oncologic and Nononcologic Diseases. Cancer J 2024; 30:210-217. [PMID: 38753756 DOI: 10.1097/ppo.0000000000000719] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
ABSTRACT Fibroblast activation protein inhibitor positron emission tomography (PET) has gained interest for its ability to demonstrate uptake in a diverse range of tumors. Its molecular target, fibroblast activation protein, is expressed in cancer-associated fibroblasts, a major cell type in tumor microenvironment that surrounds various types of cancers. Although existing literature on FAPI PET is largely from single-center studies and case reports, initial findings show promise for some cancer types demonstrating improved imaging when compared with the widely used 18F-fludeoxyglucose PET for oncologic imaging. As we expand our knowledge of the utility of FAPI PET, accurate understanding of noncancerous uptake seen on FAPI PET is crucial for accurate evaluation. In this review, we summarize potential diagnostic and therapeutic applications of radiolabeled FAP inhibitors in oncological and nononcological disease processes.
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Affiliation(s)
- Mariko Nakayama
- From the Department of Radiological Sciences, UCLA, Los Angeles, CA, USA
| | - Thomas A Hope
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
| | - Ali Salavati
- Division of Nuclear Medicine and Translational Theranostics, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
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3
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Hadad B, Aryana K, Kamali H, Askari E. 99m Tc-HYNIC-FAPI-46 SPECT/CT Uptake in Lactating Breasts. Clin Nucl Med 2024; 49:e184-e185. [PMID: 38377358 DOI: 10.1097/rlu.0000000000005102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
ABSTRACT A 36-year-old woman with a history of medullary thyroid carcinoma was referred for 99m Tc-HYNIC-FAPI-46 scan. Her calcitonin levels gradually increased after external beam radiation therapy, whereas her CEA levels were stable. A few suspicious tumoral lymphadenopathies were localized to the superior mediastinum. Interestingly, bilateral physiologic breast uptake was noticed, which was presumed to be due to lactation in the past 18 months. To our knowledge, physiologic breast uptake in 99m Tc-HYNIC-FAPI imaging has not been previously reported.
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Affiliation(s)
- Bentolhoda Hadad
- From the Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad
| | - Kamran Aryana
- From the Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad
| | - Hassan Kamali
- Chemistry Department, Kharazmi University, Tehran, Iran
| | - Emran Askari
- From the Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad
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4
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O'Brien SR, Ward R, Wu GG, Bagheri S, Kiani M, Challa A, Ulaner GA, Pantel AR, McDonald ES. Other Novel PET Radiotracers for Breast Cancer. PET Clin 2023; 18:557-566. [PMID: 37369615 DOI: 10.1016/j.cpet.2023.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Many novel PET radiotracers have demonstrated potential use in breast cancer. Although not currently approved for clinical use in the breast cancer population, these innovative imaging agents may one day play a role in the diagnosis, staging, management, and even treatment of breast cancer.
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Affiliation(s)
- Sophia R O'Brien
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA.
| | - Rebecca Ward
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Grace G Wu
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Sina Bagheri
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA. https://twitter.com/Sina_Bagherii
| | - Mahsa Kiani
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Ashrit Challa
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Gary A Ulaner
- Molecular Imaging and Therapy, Hoag Family Cancer Institute, Irvine, CA 92618, USA; Radiology and Translational Genomics, University of Southern California, Los Angeles, CA 90033, USA
| | - Austin R Pantel
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Elizabeth S McDonald
- Department of Radiology, Hospital of the University of Pennsylvania, 1 Donner, 3400 Spruce Street, Philadelphia, PA 19104, USA.
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Bentestuen M, Al-Obaydi N, Zacho HD. FAPI-avid nonmalignant PET/CT findings: An expedited systematic review. Semin Nucl Med 2023; 53:694-705. [PMID: 36813670 DOI: 10.1053/j.semnuclmed.2023.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/01/2023] [Indexed: 02/22/2023]
Abstract
Fibroblast activation protein inhibitor (FAPI) is a promising tracer in oncologic positron emission tomography/computed tomography (PET/CT). Numerous studies have demonstrated the superior sensitivity of FAPI PET/CT over fluorodeoxyglucose (FDG) PET/CT in several types of cancer. However, the cancer specificity of FAPI uptake remains understudied, and several cases of false-positive FAPI PET/CT findings have been reported. A systematic search of PubMed, Embase, and Web of Science was conducted for studies published prior to April 2022 reporting nonmalignant FAPI PET/CT findings. We included original peer-reviewed articles of studies in humans using FAPI tracers radiolabeled with 68Ga or 18F that were published in English. Papers without original data and studies with insufficient information were excluded. Nonmalignant findings were presented on a per-lesion basis and grouped according to the type of organ or tissue involved. The search identified a total of 1.178 papers, of which 108 studies were eligible. Eighty studies were case reports (74%), and the remaining 28 were cohort studies (26%). A total of 2.372 FAPI-avid nonmalignant findings were reported, with the most frequent being uptake in the arteries, e.g., related to plaques (n = 1178, 49%). FAPI uptake was also frequently related to degenerative and traumatic bone and joint lesions (n = 147, 6%) or arthritis (n = 92, 4%). For organs, diffuse or focal uptake was often seen in cases of inflammation, infection, fibrosis, and IgG4-related disease (n = 157, 7%). FAPI-avid inflammatory/reactive lymph nodes (n = 121, 5%) and tuberculosis lesions (n = 51, 2%) have been reported and could prove to be potential pitfalls in cancer staging. Periodontitis (n = 76, 3%), hemorrhoids (n = 47, 2%), and scarring/wound healing (n = 35, 2%) also presented as focal uptake on FAPI PET/CT. The present review provides an overview of the reported FAPI-avid nonmalignant PET/CT findings to date. A large number of benign clinical entities may show FAPI uptake and should be kept in mind when interpreting FAPI PET/CT findings in patients with cancer.
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Affiliation(s)
- Morten Bentestuen
- Department of Nuclear Medicine and Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, North Jutland Region, Denmark.
| | - Noor Al-Obaydi
- Department of Nuclear Medicine and Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, North Jutland Region, Denmark
| | - Helle D Zacho
- Department of Nuclear Medicine and Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, North Jutland Region, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, North Jutland Region, Denmark
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Dendl K, Koerber SA, Watabe T, Haberkorn U, Giesel FL. Current Status of Fibroblast Activation Protein Imaging in Gynecologic Malignancy and Breast Cancer. PET Clin 2023; 18:345-351. [PMID: 37257985 DOI: 10.1016/j.cpet.2023.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
68Ga-FAPI-PET/computed tomography (CT) is a novel PET/CT radiotracer particularly developed for oncologic imaging. Gynecologic malignancies comprise a broad spectrum of entities and, along with breast cancer, constitute cancers occurring exclusively or primarily, respectively, in women. Thus, a tracer designed not only for one but multiple malignancies has theoretic attractions. Even in comparison with 18F-FDG, the current standard oncologic tracer of nuclear medicine, 68Ga-FAPI, has demonstrated advantages in several tumors. As breast cancer, ovarian cancer, and cervical cancer are among the most common tumor types in women and are often accompanied by high morbidity as well as mortality rates, a reliable staging tool is paramount for optimal therapeutic management.
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Affiliation(s)
- Katharina Dendl
- Department of Nuclear Medicine, INF 400, University Hospital Heidelberg, Heidelberg, Germany; Deaprtment of Nuclear medicine, Geb. 13.55, Moorenstraße 5, 40225 Düsseldorf.
| | - Stefan A Koerber
- Department of Radiooncology and Radiation Therapy, Krankenhaus Barmherzige Brüder, Prüfeninger Str. 86 93049 Regensburg, Germany; Department of Radiooncology and Radiation Therapy, University Hospital Heidelberg
| | - Tadashi Watabe
- Department of Nuclear Medicine, 2-15 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Uwe Haberkorn
- Department of Nuclear Medicine, INF 400, University Hospital Heidelberg, Heidelberg, Germany
| | - Frederik L Giesel
- Department of Nuclear Medicine, INF 400, University Hospital Heidelberg, Heidelberg, Germany; Deaprtment of Nuclear medicine, Geb. 13.55, Moorenstraße 5, 40225 Düsseldorf
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He T, Li X, Liang C, Wu J, Cai H. Diffusely increased breast uptake of [ 18F]AlF-NOTA-FAPI-04 related to menstrual status in a patient with papillary thyroid cancer. Eur J Nucl Med Mol Imaging 2023; 50:2228-2229. [PMID: 36847825 DOI: 10.1007/s00259-023-06148-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/12/2023] [Indexed: 03/01/2023]
Affiliation(s)
- Tao He
- Department of Nuclear Medicine, Panzhihua Central Hospital, Panzhihua, 617000, China
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiangyu Li
- Department of Nuclear Medicine, Panzhihua Central Hospital, Panzhihua, 617000, China
| | - Changping Liang
- Department of Nuclear Medicine, Panzhihua Central Hospital, Panzhihua, 617000, China
| | - Jie Wu
- Department of Nuclear Medicine, Panzhihua Central Hospital, Panzhihua, 617000, China
| | - Huawei Cai
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
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8
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Mei R, Kessler L, Pabst KM, Weber M, Schimdkonz C, Rischpler C, Zacho HD, Hope T, Schwarzenböck SM, Allen-Auerbach M, Emmett L, Ferdinandus J, Unterrainer M, Schaarschmidt BM, Umutlu L, Farolfi A, Castellucci P, Nanni C, Telo S, Fanti S, Herrmann K, Fendler WP. 68Ga-FAPI PET/CT Interobserver Agreement on Tumor Assessment: An International Multicenter Prospective Study. J Nucl Med 2023:jnumed.122.265245. [PMID: 37230530 DOI: 10.2967/jnumed.122.265245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/21/2023] [Indexed: 05/27/2023] Open
Abstract
68Ga-fibroblast activation protein inhibitors (FAPIs) are promising radiotracers for cancer imaging, with emerging data in the recent years. Nonetheless, the interobserver agreement on 68Ga-FAPI PET/CT study interpretations in cancer patients remains poorly understood. Methods: 68Ga-FAPI PET/CT was performed on 50 patients with various tumor entities (sarcoma [n = 10], colorectal cancer [n = 10], pancreatic adenocarcinoma [n = 10], genitourinary cancer [n = 10], and other types of cancer [n = 10]). Fifteen masked observers reviewed and interpreted the images using a standardized approach for local, local nodal, and metastatic involvement. Observers were grouped by experience as having a low (<30 prior 68Ga-FAPI PET/CT studies; n = 5), intermediate (30-300 studies; n = 5), or high level of experience (>300 studies; n = 5). Two independent readers with a high level of experience and unmasked to clinical information, histopathology, tumor markers, and follow-up imaging (CT/MRI or PET/CT) served as the standard of reference (SOR). Observer groups were compared by overall agreement (percentage of patients matching SOR) and Fleiss κ with mean and corresponding 95% CI. We defined acceptable agreement as a κ value of at least 0.6 (substantial or higher) and acceptable accuracy as at least 80%. Results: Highly experienced observers agreed substantially on all categories (primary tumor: κ = 0.71; 95% CI, 0.71-0.71; local nodal involvement: κ = 0.62; 95% CI, 0.61-0.62; distant metastasis: κ = 0.75; 95% CI, 0.75-0.75), whereas observers with intermediate experience showed substantial agreement on primary tumor (κ = 0.73; 95% CI, 0.73-0.73) and distant metastasis (κ = 0.65; 95% CI, 0.65-0.65) but moderate agreement on local nodal stages (κ = 0.55; 95% CI, 0.55-0.55). Observers with low experience had moderate agreement on all categories (primary tumor: κ = 0.57; 95% CI, 0.57-0.58; local nodal involvement: κ = 0.51; 95% CI, 0.51-0.52; distant metastasis: κ = 0.54; 95% CI, 0.53-0.54). Compared with SOR, the accuracy for readers with high, intermediate, and low experience was 85%, 83%, and 78%, respectively. In summary, only highly experienced readers showed substantial agreement and a diagnostic accuracy of at least 80% in all categories. Conclusion: The interpretation of 68Ga-FAPI PET/CT for cancer imaging had substantial reproducibility and accuracy among highly experienced observers only, especially for local nodal and metastatic assessments. Therefore, for accurate interpretation of different tumor entities and pitfalls, we recommend training or experience with at least 300 representative scans for future clinical readers.
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Affiliation(s)
- Riccardo Mei
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Lukas Kessler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
| | - Kim M Pabst
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
| | - Manuel Weber
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
| | | | - Christoph Rischpler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
| | | | - Thomas Hope
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California
| | | | - Martin Allen-Auerbach
- Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California
- Institute of Urologic Oncology, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Louise Emmett
- Department of Theranostics and Nuclear Medicine, St. Vincent's Hospital, and Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Justin Ferdinandus
- Department of Internal Medicine I, University of Cologne, Cologne, Germany
| | - Marcus Unterrainer
- Department of Radiology, University Hospital LMU Munich, Munich, Germany; and
| | - Benedikt M Schaarschmidt
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Andrea Farolfi
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Paolo Castellucci
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Cristina Nanni
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Silvi Telo
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Stefano Fanti
- Nuclear Medicine Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Ken Herrmann
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
| | - Wolfgang P Fendler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium, Partner Site University Hospital Essen, and German Cancer Research Center, Essen, Germany
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Hotta M, Rieger AC, Jafarvand MG, Menon N, Farolfi A, Benz MR, Calais J. Non-oncologic incidental uptake on FAPI PET/CT imaging. Br J Radiol 2023; 96:20220463. [PMID: 35776566 PMCID: PMC9975522 DOI: 10.1259/bjr.20220463] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/22/2022] [Accepted: 06/29/2022] [Indexed: 01/29/2023] Open
Abstract
Fibroblast-activation protein (FAP) is a serine protease classified in the dipeptidyl peptidase 4 (DPP4) family. FAP is predominantly expressed in activated fibroblasts such as the cancer-associated fibroblasts (CAFs). FAP expression in CAFs is associated with tumor progression and poor prognosis in solid cancers. Recently, radiolabeled FAP inhibitors (FAPI) has been developed, which enables positron emission tomography (PET) imaging of FAP. FAPI PET/CT can provide a higher tumor-to-background ratio (TBR) than 18F-fludeoxyglucose PET/CT in various cancers, and thus has attracted substantial attention. As studies on FAPI PET grow in number and size, incidental findings related to non-oncologic conditions have been increasingly reported. FAPI PET uptake has been reported in various conditions such as benign tumors, fibrotic, granulomatosis, scarring/wound, degenerative diseases, and inflammatory diseases.The knowledge of physiological and non-oncologic causes of FAPI uptake is indispensable for accurate FAPI PET/CT interpretation and can help appropriate management of incidental findings on FAPI PET/CT in patients referred for cancer staging indications. In this review article, we describe for each organ system (Brain, Oral mucosa, Salivary Glands, Thyroid, Lung, Myocardium, Breast, Esophagus, Stomach, Intestine, Liver, Gallbladder, Pancreas, Spleen, Kidney, , Uterus, Bone marrow, Joints, Muscle, Vessels, Lymph nodes), the patterns of physiological FAPI uptake and the main causes of non-oncological uptake reported from the literature with FAPI-02, FAPI-04 and FAPI-46. We also illustrate some examples from our institutional database at UCLA.
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Affiliation(s)
- Masatoshi Hotta
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
| | - Angela C Rieger
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
| | - Mahbod G Jafarvand
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
| | - Nandakumar Menon
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
| | - Andrea Farolfi
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
| | | | - Jeremie Calais
- Ahmanson Translational Theranostics Division, Department of Molecular & Medical Pharmacology, University of California, Los Angeles, USA
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PET/CT with Fibroblast Activation Protein Inhibitors in Breast Cancer: Diagnostic and Theranostic Application-A Literature Review. Cancers (Basel) 2023; 15:cancers15030908. [PMID: 36765866 PMCID: PMC9913570 DOI: 10.3390/cancers15030908] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Growing studies have recently reported on the promising application of radiolabeled-fibroblast activation protein inhibitors (FAPIs) as diagnostic and therapeutic agents in various oncological populations. To exclusively evaluate the current evidence on the diagnostic and therapeutic role of FAPI radiotracers in patients with breast cancer (BC), a narrative review of the available literature was performed. A search algorithm from PubMed/MEDLINE, based on the combination of "PET" OR "positron emission tomography" and "FAPI" and "cancer", with a last update in February 2022, was applied. From 233 identified articles, 33 studies conducted in BC patients and with available data on PET imaging or radiolabeled-FAPI therapy were finally considered, for a total of 191 patients. Despite some clinical and methodological heterogeneity among the reviewed articles, 68Ga-FAPI PET/CT emerges as a valuable diagnostic tool in BC patients both at staging and restaging, also demonstrating several technical advantages and an overall better performance than 18F-FDG, especially in histotypes with well-known low 18F-FDG avidity. Moreover, although with still limited clinical evidence in BC, radiolabeled FAPIs emerge as promising therapeutic agents in a theranostic perspective, increasing the possibility of more personalized treatments. From these results, future research directions on FAPI radiotracers application in BC patients are suggested.
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11
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Dendl K, Koerber SA, Tamburini K, Mori Y, Cardinale J, Haberkorn U, Giesel FL. Advancement and Future Perspective of FAPI PET/CT In Gynecological Malignancies. Semin Nucl Med 2022; 52:628-634. [PMID: 35842334 DOI: 10.1053/j.semnuclmed.2022.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/10/2022] [Accepted: 04/13/2022] [Indexed: 01/18/2023]
Abstract
Fibroblast activation protein (FAP) is ubiquitously present in healthy tissue, and additionally upregulated by cancer associated fibroblasts (CAFs) leading to high levels of FAP. Thus, neoplastic tissue, which is containing CAFs, characterized by a high presence of FAP. Moreover, in more than 90% of all epithelial tumors this phenomenon seems to occur, including many gynecological tumors, providing the foundation for a successful application of FAP-ligands. However, FAP upregulation, can also be initiated by benign conditions such as inflammation, hormonal-influence, and wound healing. Gynecological cancers seem to represent a field of interest for the utilization of FAPI-PET/CT to potentially improve staging, restaging and therapeutic management. First highly promising investigations demand further research in order to validate these preliminary findings.
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Affiliation(s)
- Katharina Dendl
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany; Department of Nuclear Medicine, Heinrich-Heine-University, Medical Faculty and University Hospital Duesseldorf, Duesseldorf Germany.
| | - Stefan A Koerber
- Department of Radiation Oncology, Heidelberg University Hospital, Germany; Department of Radiation Oncology, Heidelberg Institute of Radiation Oncology (HIRO), Germany; Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Germany
| | | | - Yuriko Mori
- Department of Nuclear Medicine, Heinrich-Heine-University, Medical Faculty and University Hospital Duesseldorf, Duesseldorf Germany
| | - Jens Cardinale
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany; Department of Nuclear Medicine, Heinrich-Heine-University, Medical Faculty and University Hospital Duesseldorf, Duesseldorf Germany
| | - Uwe Haberkorn
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany; Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Germany; Translational Lung Research Center Heidelberg, German Center for Lung Research DZL, Germany
| | - Frederik L Giesel
- Department of Nuclear Medicine, University Hospital Heidelberg, Germany; Department of Nuclear Medicine, Heinrich-Heine-University, Medical Faculty and University Hospital Duesseldorf, Duesseldorf Germany
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12
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Kou Y, Jiang X, Yao Y, Shen J, Jiang X, Chen S, Lu H, Wang X, Zhao M, Xiao D, Shen T, Zhang W, Cheng Z. Physiological tracer distribution and benign lesion incidental uptake of Al18F-NOTA-FAPI-04 on PET/CT imaging. Nucl Med Commun 2022; 43:847-854. [PMID: 35506283 DOI: 10.1097/mnm.0000000000001563] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To systematically investigate the physiological distribution and benign lesion incidental uptake of Al18F-NOTA-FAPI-04 (18F-FAPI) in cancer patients to establish the normal uptake range in relevant organs and lesions. METHODS Twenty patients who underwent 18F-FAPI PET/CT imaging were retrospectively assessed. Organ and benign lesion tracer uptake was quantified based on standardized uptake values (SUVmax and SUVmean). We compared the variation in tracer uptake in certain organs between men and women, analyzed the possible reasons for diffuse uptake in the thyroid, and assessed tracer uptake variations in the uterus in different menstrual cycle phases. Incidental tracer uptake in benign lesions was also assessed. RESULTS Physiological 18F-FAPI uptake was observed in the urinary tract, biliary tract system, submandibular glands, pancreas, thyroid, uterus, intestine, prostate gland, parotid gland, myocardium, kidney cortex, and muscles, but not the brain, lungs, liver, spleen, colon, and breasts. The SUVmean for each organ was similar for women and men (all P > 0.05). Diffuse tracer uptake in the thyroid was caused by normal thyroid or thyroiditis; there were no statistically significant differences between them (SUVmax: t = -1.3, P = 0.25; SUVmean: t = -1.1, P = 0.31). There was a significant difference for uterus uptake among different menstrual cycle phases (SUVmax: F = 5.08, P = 0.04; SUVmean: F = 5.19, P = 0.04). Incidental benign lesion tracer uptake was observed in patients with esophagitis, thyroiditis, arthritis, fractures, and uterine fibroids. CONCLUSION This study provides a reference range for 18F-FAPI uptake in relevant organs and benign lesions. Benign lesion 18F-FAPI uptake may reduce 18F-FAPI PET/CT specificity.
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Affiliation(s)
- Ying Kou
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Xuemei Jiang
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Yutang Yao
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Jiaqi Shen
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Xiao Jiang
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
- Institute of Isotope, China Institute of Atomic Energy, Beijing, China
| | - Shirong Chen
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Hao Lu
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Xiaoxiong Wang
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Meng Zhao
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Dingqiong Xiao
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Taipeng Shen
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Wei Zhang
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
| | - Zhuzhong Cheng
- The PET/CT Center, Department of Nuclear Medicine, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, People's Republic of China
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Roustaei H, Kiamanesh Z, Askari E, Sadeghi R, Aryana K, Treglia G. Could Fibroblast Activation Protein (FAP)-Specific Radioligands Be Considered as Pan-Tumor Agents? CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:3948873. [PMID: 35280710 PMCID: PMC8888077 DOI: 10.1155/2022/3948873] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/10/2021] [Accepted: 01/29/2022] [Indexed: 02/07/2023]
Abstract
Background Cancer-associated fibroblasts (CAFs) can strongly modulate the response to therapy of malignant tumor cells, facilitating their continuous proliferation and invading behaviors. In this context, several efforts were made in identifying the fibroblast activation protein (FAP) as a CAF recognizer and in designing FAP-specific PET radiotracers (as 68Ga-FAPI) along with FAP-specific therapeutic radioligands. Herein, we review different clinical studies using the various FAP-specific radioligands as novel theranostic agents in a wide range of oncologic and nononcologic indications. Methods A comprehensive systematic search was conducted on the PubMed and Scopus databases to find relevant published articles concerning the FAP-specific PET imaging as well as the FAP-specific radionuclide therapy in patients with oncologic and nononcologic indications. The enrolled studies were dichotomized into oncologic and nononcologic categories, and the required data were extracted by precisely reviewing the whole text of each eligible study. A meta-analysis was also performed comparing the detection rates of 68Ga-FAPI vs. 18F-FDG PET/CT using odds ratio (OR) and risk difference as outcome measures. Results Of the initial 364 relevant papers, 49 eligible articles (1479 patients) and 55 case reports were enrolled in our systematic review. These studies observed high radiolabeled FAPI avidity as early as 10 minutes after administration in primary sites of various malignant tumors. Based on the meta-analysis which was done on the reported detection rates of the 68Ga-FAPI and 18F-FDG PET/CT scans, the highest OR belonged to the primary lesion detection rate of gastrointestinal tumors (OR = 32.079, 95% CI: 4.001-257.212; p = 0.001) with low heterogeneity (I2 = 0%). The corresponding value of the nodal metastases belonged to hepatobiliary tumors (OR = 11.609, 95% CI: 1.888-71.365; p = 0.008) with low heterogeneity (I2 = 0%). For distant metastases, the highest estimated OR belonged to nasopharyngeal carcinomas (OR = 77.451, 95% CI: 7.323-819.201; p < 0.001) with low heterogeneity (I2 = 0%). Conclusions The outperformance of 68Ga-FAPI PET/CT over 18F-FDG PET/CT in identifying certain primary tumors as well as in detecting their metastatic lesions may open indications for evaluation of cases with inconclusive 18F-FDG PET/CT findings. What needs to be emphasized is that the false-positive results might be problematic and must be taken into account in 68Ga-FAPI PET/CT interpretation. More clarification on the role of FAPI radioligands in oncologic imaging, radionuclide therapy, and radiotherapy treatment planning is therefore required.
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Affiliation(s)
- Hessamoddin Roustaei
- Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra Kiamanesh
- Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Emran Askari
- Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ramin Sadeghi
- Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Kamran Aryana
- Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Giorgio Treglia
- Ente Ospedaliero Cantonale, Bellinzona, Switzerland
- Faculty of Biomedical Sciences, Universitá della Svizzera italiana, Lugano, Switzerland
- Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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Yang T, Ma L, Hou H, Gao F, Tao W. FAPI PET/CT in the Diagnosis of Abdominal and Pelvic Tumors. Front Oncol 2022; 11:797960. [PMID: 35059319 PMCID: PMC8763785 DOI: 10.3389/fonc.2021.797960] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/23/2021] [Indexed: 12/11/2022] Open
Abstract
Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18F-FDG) is currently a standard imaging examination used in clinical practice, and plays an essential role in preoperative systemic evaluation and tumor staging in patients with tumors. However, 18F-FDG PET/CT has certain limitations in imaging of some tumors, like gastric mucus adenocarcinoma, highly differentiated hepatocellular carcinoma, renal cell carcinoma, and peritoneal metastasis. Therefore, to search for new tumor diagnosis methods has always been an important topic in radiographic imaging research. Fibroblast activation protein (FAP) is highly expressed in many epithelial carcinomas, and various isotope-labelled fibroblast activation protein inhibitors (FAPI) show lower uptake in the brain and abdominal tissues than in tumor, thus achieving high image contrast and good tumor delineation. In addition to primary tumors, FAPI PET/CT is better than FDG PET/CT for detecting lymph nodes and metastases. Additionally, the highly selective tumor uptake of FAPI may open up new application areas for the non-invasive characterization, staging of tumors, as well as monitoring tumor treatment efficacy. This review focuses on the recent research progress of FAPI PET/CT in the application to abdominal and pelvic tumors, with the aim of providing new insights for diagnostic strategies for tumor patients, especially those with metastases.
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Affiliation(s)
- Tianshuo Yang
- Department of Nuclear Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Long Ma
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Haodong Hou
- Key Laboratory for Experimental Teratology of the Ministry of Education and Center for Experimental Nuclear Medicine, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Feng Gao
- Key Laboratory for Experimental Teratology of the Ministry of Education and Center for Experimental Nuclear Medicine, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Weijing Tao
- Department of Nuclear Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
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15
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Kessler L, Ferdinandus J, Hirmas N, Zarrad F, Nader M, Kersting D, Weber M, Kazek S, Sraieb M, Hamacher R, Lueckerath K, Umutlu L, Fendler WP, Rischpler C. Pitfalls and common findings in 68Ga-FAPI-PET - A pictorial analysis. J Nucl Med 2021; 63:890-896. [PMID: 34620730 DOI: 10.2967/jnumed.121.262808] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/20/2021] [Indexed: 11/16/2022] Open
Abstract
Introduction: Fibroblast activation protein inhibitor positron emission tomography (FAPI-PET) is a new tool in the diagnostic workup of cancer. With growing volume of applications pitfalls and common findings need to be considered for Ga-68-FAPI-PET image interpretation. The aim of this study was to summarize common findings and report pitfalls in Ga-68-FAPI-PET. Methods and materials: 91 patients underwent whole-body PET/CT with either FAPI-04 (N = 25) or FAPI-46 (N = 66). Findings were rated in a consensus session of two experienced readers. Pitfalls and common findings were defined as focal or localized uptake above background and categorized as unspecific / non-malignant and grouped into degenerative, muscular, scarring / wound-healing, uterine, mammary glands and head-and-neck findings. Frequency of findings was reported on a per-patient and per-group basis and SUVmax, SUVmean and SUVpeak was measured. Results: Non-tumor specific tracer uptake was found in 81.3 % of patients. The most frequent finding was tracer uptake in degenerative lesions (51.6%) with mean SUVmax 7.7 ± 2.9 and head-and-neck (45.1%) findings. Except for salivary glands, the uptake values did not differ between 10 and 60 min p.i. in most findings. Uterine uptake was found in most women (66.7%) with mean SUVmax 12.2 ± 7.3 and uptake correlated negatively with age (SUVmax r = -0.6, p<0.01; SUVpeak r = -0.57, p<0.01; SUVmean r = -0.58, p<0.01). Conclusion: Pitfalls include non-tumor specific Ga-68-FAPI uptake in degenerative lesions, muscle, head-and-neck, scarring, mammary glands or uterus. Here we summarize findings to inform readers at centers introducing Ga-68-FAPI-PET to avoid common mistakes.
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Affiliation(s)
- Lukas Kessler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Justin Ferdinandus
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Nader Hirmas
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Fadi Zarrad
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Michael Nader
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - David Kersting
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Manuel Weber
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Sandra Kazek
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Miriam Sraieb
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Rainer Hamacher
- Department of Medical Oncology, University Hospital Essen, University of Duisburg-Essen
| | - Katharina Lueckerath
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Lale Umutlu
- Institute of Diagnostic and Interventional Radiology, University of Duisburg-Essen
| | - Wolfgang P Fendler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
| | - Christoph Rischpler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Germany
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Dendl K, Koerber SA, Kratochwil C, Cardinale J, Finck R, Dabir M, Novruzov E, Watabe T, Kramer V, Choyke PL, Haberkorn U, Giesel FL. FAP and FAPI-PET/CT in Malignant and Non-Malignant Diseases: A Perfect Symbiosis? Cancers (Basel) 2021; 13:4946. [PMID: 34638433 PMCID: PMC8508433 DOI: 10.3390/cancers13194946] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/10/2021] [Accepted: 09/10/2021] [Indexed: 12/13/2022] Open
Abstract
A fibroblast activation protein (FAP) is an atypical type II transmembrane serine protease with both endopeptidase and post-proline dipeptidyl peptidase activity. FAP is overexpressed in cancer-associated fibroblasts (CAFs), which are found in most epithelial tumors. CAFs have been implicated in promoting tumor cell invasion, angiogenesis and growth and their presence correlates with a poor prognosis. However, FAP can generally be found during the remodeling of the extracellular matrix and therefore can be detected in wound healing and benign diseases. For instance, chronic inflammation, arthritis, fibrosis and ischemic heart tissue after a myocardial infarction are FAP-positive diseases. Therefore, quinoline-based FAP inhibitors (FAPIs) bind with a high affinity not only to tumors but also to a variety of benign pathologic processes. When these inhibitors are radiolabeled with positron emitting radioisotopes, they provide new diagnostic and prognostic tools as well as insights into the role of the microenvironment in a disease. In this respect, they deliver additional information beyond what is afforded by conventional FDG PET scans that typically report on glucose uptake. Thus, FAP ligands are considered to be highly promising novel tracers that offer a new diagnostic and theranostic potential in a variety of diseases.
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Affiliation(s)
- Katharina Dendl
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
- Department of Nuclear Medicine, Düsseldorf University Hospital, 40225 Düsseldorf, Germany; (M.D.); (E.N.)
| | - Stefan A. Koerber
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany;
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Clemens Kratochwil
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
| | - Jens Cardinale
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
- Department of Nuclear Medicine, Düsseldorf University Hospital, 40225 Düsseldorf, Germany; (M.D.); (E.N.)
| | - Rebecca Finck
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
| | - Mardjan Dabir
- Department of Nuclear Medicine, Düsseldorf University Hospital, 40225 Düsseldorf, Germany; (M.D.); (E.N.)
| | - Emil Novruzov
- Department of Nuclear Medicine, Düsseldorf University Hospital, 40225 Düsseldorf, Germany; (M.D.); (E.N.)
| | - Tadashi Watabe
- Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan;
| | - Vasko Kramer
- Positronpharma SA, Santiago 7500921, Chile;
- Center of Nuclear Medicine, PositronMed, Santiago 7501068, Chile
| | - Peter L. Choyke
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1088, USA;
| | - Uwe Haberkorn
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Translational Lung Research Center Heidelberg, German Center for Lung Research DZL, 69120 Heidelberg, Germany
| | - Frederik L. Giesel
- Department of Nuclear Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany; (C.K.); (J.C.); (R.F.); (U.H.); (F.L.G.)
- Department of Nuclear Medicine, Düsseldorf University Hospital, 40225 Düsseldorf, Germany; (M.D.); (E.N.)
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68Ga-FAPI-PET/CT improves diagnostic staging and radiotherapy planning of adenoid cystic carcinomas - Imaging analysis and histological validation. Radiother Oncol 2021; 160:192-201. [PMID: 33940087 PMCID: PMC9913884 DOI: 10.1016/j.radonc.2021.04.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUND Adenoid cystic carcinomas (ACCs) are rare epithelial tumors mostly situated in the head and neck region and characterized by infiltrative growth. The tumor stroma of ACCs includes cancer-associated fibroblasts (CAFs) expressing Fibroblast Activation Protein (FAP), a new target for positron emission tomography (PET) imaging. Here we describe the value of PET/ computed tomography (PET/CT) imaging using 68Ga-labelled FAP-Inhibitors (68Ga-FAPI-PET/CT) and their clinical potential for staging and radiotherapy planning in 12 ACC patients (7 primary, 5 recurrent). PATIENTS AND METHODS Patients underwent contrast enhanced staging CT (ceCT) and magnetic resonance imaging (ceMRI) before 68Ga-FAPI - PET/CT. PET-scans were acquired 10, 60 and 180 minutes after administration of 150-250 MBq of 68Ga-labelled FAPI tracers. SUVmax and SUVmean values of ACCs and healthy organs were obtained using a 60% of maximum iso-contour. FAP and alpha smooth muscle actin (α-SMA) immunohistochemistry was performed in 13 cases (3 with and 10 without 68Ga FAPI-PET/CT). Staging and radiotherapy planning based on 68Ga-FAPI-PET/CT versus ceCT/MRI alone were compared. RESULTS We observed elevated tracer uptake in all ACCs. Immunohistochemistry showed FAP-expressing CAFs in the tumor. Compared to conventional staging, 68Ga-FAPI-PET/CT led to upstaging in 2/12 patients and to detection of additional metastases in 3 patients, thus in total 42% of patients had their staging altered. Moreover, 68Ga-FAPI PET improved the accuracy of target volume delineation for radiotherapy, as compared to CT and MRI. CONCLUSION 68Ga-FAPI-PET/CT is a promising imaging modality for ACC, increasing the accuracy of staging exams and radiotherapy planning volumes, as compared conventional to CT and MRI.
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Abstract
Fibroblast activation protein inhibitor emerges as a novel and highly promising agent for diagnostic and possibly theranostic application in various malignant and non-malignant diseases. FAPI impresses with its selective expression in several pathologies, ligand induced internalization, and presence in a large variety of malignancies. Current studies indicate that FAPI is equal or even superior to the current standard oncological tracer fluorodeoxyglucose in several oncological diseases. It seems to present lower background activity, stronger uptake in tumorous lesions and thus sharper contrasts. For improved comprehension of fibroblast activation, protein expression and clinicopathologic conditions, further studies are of essence.
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