Fibroblast Activation Protein-Targeted PET/CT with F-Fibroblast Activation Protein Inhibitor-74 for Evaluation of Gastrointestinal Cancer: Comparison with F-FDG PET/CT.

Fibroblast activation protein is overexpressed in the stroma of several cancer types. F-fibroblast activation protein inhibitor (FAPI)-74 is a PET tracer with high selectivity for fibroblast activation protein and has shown high accumulation in human tumors in clinical studies. However, the use of F-FAPI-74 for PET imaging of gastrointestinal cancer has not been systematically investigated.

Visualization of Intermetastatic Heterogeneity in Mixed Neuroendocrine Carcinoma-Acinar Adenocarcinoma of the Prostate by 68 Ga-PSMA, 68 Ga-FAPI, and 18 F-FDG PET/CT.

Mixed neuroendocrine carcinoma-acinar carcinoma is an uncommon histological type of neuroendocrine prostate cancer. It has been rarely reported in de novo prostate malignancies. In this case, we present 68 Ga-PSMA (prostate-specific membrane antigen), 68 Ga-FAPI, and 18 F-FDG PET/CT findings in the de novo form of mixed large-cell neuroendocrine carcinoma-acinar adenocarcinoma of the prostate.

68 Ga-FAPI Versus 18 F-FDG PET/CT in the Evaluation of Epithelioid Hemangioendothelioma of Bone.

Epithelioid hemangioendothelioma (EHE) is a rare type of vascular tumor that may arise in bone. Here we presented a 62-year-old man with suspected bone metastases who underwent PET/CT to detect the primary tumor. He underwent 18 F-FDG and 68 Ga-FAPI PET/CT under the prospective trial NCT04416165.

PET Imaging of Fibroblast Activation Protein in Various Types of Cancer Using Ga-FAP-2286: Comparison with F-FDG and Ga-FAPI-46 in a Single-Center, Prospective Study.

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 Ga-FAP-2286 to detect primary and metastatic lesions in patients with various types of cancer, compared with F-FDG and Ga-FAP-2286.

Comparison of [Ga]Ga-FAPI and [F]FDG uptake in patients with gastric signet-ring-cell carcinoma: a multicenter retrospective study.

Objective: In this study, we investigated the role of [Ga]Ga-FAPI PET imaging in the detection of primary and metastatic gastric signet-ring-cell carcinoma (GSRCC) and compared with [F]FDG PET.

Methods: This retrospective multicenter analysis included 34 patients with histologically confirmed GSRCCs from four medical centers. The maximum standard uptake value (SUV), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities.

68 Ga-FAPI PET/CT Detected Non-PSMA/FDG-Avid Primary Tumor in De Novo Metastatic Prostate Cancer.

68 Ga-labeled PET tracer targeting PSMA is a promising diagnostic approach for staging and restating of prostate cancer (PCa), but cases with clinically relevant PCa and false-negative PSMA PET/CT have been reported. In this case, we reported 68 Ga-PSMA, 18 F-FDG, and 68 Ga-FAPI PET/CT findings in a 65-year-old man with de novo metastatic PCa. 68 Ga-FAPI PET/CT detected non-PSMA/FDG-avid primary PCa, consisting with multiparametric MRI findings.

Serous Cystadenoma of the Pancreas Showing Increased Uptake on 68 Ga-FAPI PET/CT.

Serous cystadenoma of the pancreas is a type of pancreatic cystic neoplasm frequently found in clinical practice. Serous cystadenoma of the pancreas can have a varied morphological presentation on imaging examinations. Therefore, it is sometimes very challenging to differentiate serous cystadenoma of the pancreas from pancreatic malignancy.

Epiglottic Polymorphous Adenocarcinoma With Multiple Bone Metastases Detected by 68 Ga-FAPI PET/CT.

Polymorphous adenocarcinoma (PAC) is generally an indolent tumor that mostly commonly affects the minor salivary gland. Polymorphous adenocarcinoma with distant metastases is extremely rare. In this case, we reported 18 F-FDG and 68 Ga-FAPI PET/CT imaging findings in a rare case of epiglottic PAC with multiple bone metastases.

Uncommon Metastases From Occult Breast Cancer Revealed by 18 F-FDG and 68 Ga-FAPI PET/CT.

Metastases to gastrointestinal tract from breast cancer are very rare and can be diagnostically challenging. In this case, we reported 18 F-FDG and 68 Ga-FAPI PET/CT findings in a 54-year-old women with such uncommon metastases from breast cancer. Although the primary tumor of breast cancer remained radiologically occult, 68 Ga-FAPI PET/CT showed a far better tumor-to-background ratio than 18 F-FDG PET/CT for detecting the metastatic lesions, especially for detecting the retroperitoneal lymph node and rectal metastases.

Differentiation of Reactive Lymph Nodes and Tumor Metastatic Lymph Nodes With 68Ga-FAPI PET/CT in a Patient With Squamous Cell Lung Cancer.

False-positive findings of mediastinal lymph node often confound the image interpretation of the preoperative PET/CT in non-small cell lung cancer. In this case, we reported 18F-FDG and 68Ga-FAPI PET/CT findings in a patient with squamous cell lung cancer. 18F-FDG-based TNM stage was stage IIIA (T1bN2M0) due to increased uptake in the enlarged right lower paratracheal lymph node.

18F-FDG Versus 68Ga-FAPI PET/CT in Visualizing Primary Hepatic Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue.

The prevalence of primary hepatic mucosa-associated lymphoid tissue lymphomas is extremely low. In this case, we present 18F-FDG and 68Ga-FAPI PET/CT findings in a 76-year-old man with pathologically confirmed primary hepatic extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. 68Ga-FAPI PET/CT showed a better tumor-to-background ratio than 18F-FDG PET/CT in the hepatic lesion because there is little 68Ga-FAPI uptake in the liver parenchyma.

Positron emission tomography and computed tomography with [Ga]Ga-fibroblast activation protein inhibitors improves tumor detection and staging in patients with pancreatic cancer.

Purpose: This study aimed to investigate the diagnostic performance of [Ga]Ga-FAPI PET/CT for primary and metastatic pancreatic carcinoma lesions and compare the results with those of [F]-fluorodeoxyglucose ([F]FDG) PET/CT.

Methods: Patients with suspected or diagnosed pancreatic malignancy, who underwent contemporaneous [F]FDG and [Ga]Ga-FAPI PET/CT between June 2020 and January 2021, were retrospectively analyzed. Routine contrast-enhanced CT (CE-CT) is performed in all patients as standardized care.

68Ga-Exendin-4 PET/CT Differentiates Insulinoma From Accessory Spleen in a Patient Presenting Indeterminate MRI and 68Ga-DOTATATE PET/CT Findings.

A 55-year-old woman with endogenous hyperinsulinemia hypoglycemia was clinically diagnosed with insulinoma. Contrast-enhanced MRI revealed an inconclusive hypointense lesion in the pancreatic tail, and the enhancement pattern does not support the diagnosis of insulinoma. 68Ga-DOTATATE PET/CT showed intense radioactivity in this nodule, similar to the radioactivity of the adjacent spleen.

68Ga-DOTATATE PET/CT in Primary Pulmonary Lymphoepithelioma-Like Carcinoma.

Primary pulmonary lymphoepithelioma-like carcinomas (LELCs) are extremely rare tumors with better prognosis than other types of lung malignancies. In this case, we present 18F-FDG and 68Ga-DOTATATE PET/CT findings in a 52-year-old woman with pathologically confirmed pulmonary LELC. The pulmonary LELC presented mild 18F-FDG but avid 68Ga-DOTATATE uptake, indicating that the somatostatin receptor 2 may be highly expressed in LELCs.

18F-FDG and 68Ga-FAPI PET/CT in the Evaluation of Ground-Glass Opacity Nodule.

A 50-year-old woman with a newly detected pulmonary ground-glass opacity (GGO) nodule underwent PET/CT to determine the likelihood of malignancy. This patient was enrolled in the prospective study (NCT04588064) to determine the effectiveness of 18F-FDG and 68Ga-FAPI PET/CT for characterization of the GGO nodule. On PET/CT images, minimal 18F-FDG uptake but intense 68Ga-FAPI uptake was observed in this GGO nodule.