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A 46-year-old woman presented with upper abdominal pain and was initially suspected to have a pancreatic neuroendocrine tumor (NET) based on MRI signs. However, a SSTR2-targeted PET/CT scan using [68Ga]Ga-DOTATATE showed intense radiotracer uptake in the pancreatic nodule, similar to the adjacent spleen. To further differentiate between the two, a [68Ga]Ga-DOTA-LM3 PET/CT scan was performed, which showed no increased uptake in the pancreatic nodule, indicating a lower likelihood of neoplasia. A laparoscopic distal pancreatectomy confirmed the presence of an intrapancreatic accessory spleen (IPAS). This case highlights the challenges in differentiating pancreatic NETs from IPAS and suggests that [68Ga]Ga-DOTA-LM3 PET/CT may be helpful in making this distinction. [Extracted from the article]

Objective: In this study, we investigated the role of [68Ga]Ga-FAPI PET imaging in the detection of primary and metastatic gastric signet-ring-cell carcinoma (GSRCC) and compared with [18F]FDG PET. Methods: This retrospective multicenter analysis included 34 patients with histologically confirmed GSRCCs from four medical centers. The maximum standard uptake value (SUVmax), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities. [18F]FDG and [68Ga]Ga-FAPI uptakes were compared by using the Wilcoxon signed-rank test. McNemar's test was used to compare the diagnostic accuracy between the two techniques. Results: Data were analyzed from 27 paired PET/CT and 7 paired PET/MRI scans for 34 GSRCC patients (16 men and 18 women) who had a median age of 51 years (range: 25–85 years). [68Ga]Ga-FAPI PET showed higher SUVmax and TBR values than did [18F]FDG PET in the primary tumors (SUVmax: 5.2 vs. 2.2, p = 0.001; TBR: 7.6 vs. 1.3, p < 0.001), involved lymph nodes (SUVmax: 6.8 vs. 2.5, p < 0.001; TBR: 5.8 vs. 1.3, p < 0.001), and bone and visceral metastases (SUVmax: 6.5 vs. 2.4, p < 0.001; TBR: 6.3 vs. 1.3, p < 0.001). In diagnostic performance, [68Ga]Ga-FAPI PET exhibited higher sensitivity than [18F]FDG PET for detecting primary tumors (73% [16/22] vs. 18% [4/22], p < 0.001), local recurrences (100% [7/7] vs. 29% [2/7], p = 0.071), lymph node metastases (77% [59/77] vs. 23% [18/77], p < 0.001), and distant metastases (93% [207/222] vs. 39% [86/222], p < 0.001). Conclusion: The results from this multicenter retrospective analysis justify the clinical use of [68Ga]Ga-FAPI tracers for GSRCC diagnosis and staging. Key Points: • [68Ga]Ga-FAPI PET/CT is a promising imaging modality for the detection of primary and metastatic disease and has implications for TNM staging in GSRCC. • In this multicenter study of 34 patients with GSRCC, [68Ga]Ga-FAPI PET exhibited greater radiotracer uptake, tumor-to-background ratios, and diagnostic accuracy than [18F]FDG PET for detecting primary/recurrent tumors and metastatic lesions. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the diagnostic performance of [68Ga]Ga-FAPI PET/CT for primary and metastatic pancreatic carcinoma lesions and compare the results with those of [18F]-fluorodeoxyglucose ([18F]FDG) PET/CT. Methods: Patients with suspected or diagnosed pancreatic malignancy, who underwent contemporaneous [18F]FDG and [68Ga]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. Findings were confirmed by histopathology or radiographic follow-up. We compared radiotracer uptake, diagnostic performance, and TNM (tumor-node-metastasis) classifications. Results: We evaluated 36 participants (25/36 men; median age, 60 years), including 26 patients with pancreatic malignancies and ten patients with pancreatic benign lesions. [68Ga]Ga-FAPI PET/CT showed higher radiotracer uptake and higher sensitivity than [18F]FDG PET/CT in evaluating primary tumors (SUVmax, 21.4 vs. 4.8; sensitivity, 100% vs. 73.1%), involved lymph nodes (SUVmax, 8.6 vs. 2.7; sensitivity, 81.8% vs. 59.1%), and metastases (SUVmax, 7.9 vs. 3.5; sensitivity, 91.5% vs. 44.0%); Compared with [18F]FDG, [68Ga]Ga-FAPI PET/CT upstaged six patients' TNM staging (6/23, 26.1%) and changed two patients' clinical management (2/23, 8.7%). Compared with CE-CT, [68Ga]Ga-FAPI PET/CT upgraded TNM staging in five patients (5/23, 21.7%) and changed the therapeutic regimen in only one patient (1/23, 4.3%). Intense [68Ga]Ga-FAPI uptake was observed throughout the pancreas in 12/26 pancreatic malignancies; dual-time point [68Ga]Ga-FAPI PET/CT may differentiate pancreatitis from malignancy. Conclusions: Compared with [18F]FDG PET/CT, [68Ga]Ga-FAPI PET/CT shows higher sensitivity in detecting primary pancreatic tumors, involved lymph nodes, and metastases and is superior in terms of TNM staging. Prospective trials with larger patient population are needed to evaluate whether [68Ga]Ga-FAPI PET/CT could elicit treatment modification in pancreatic cancer when compared with standard of care imaging. [ABSTRACT FROM AUTHOR]

The article describes the case of a 35-year-old woman presented with 1 year history of progressive back pain. Topics covered include the findings of several laboratory tests which led to the initial diagnosis of brown tumors secondary to hyperparathyroidism, the reason that brown tumors are considered as diagnostic pitfall, and patient outcome following parathyroidectomy.

Fibroblast activation protein is overexpressed in the stroma of several cancer types. 18 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 18 F-FAPI-74 for PET imaging of gastrointestinal cancer has not been systematically investigated. Herein, we investigated the diagnostic accuracy of 18 F-FAPI-74 ( 18 F-LNC1005) PET/CT in gastric, liver, and pancreatic cancers and compared the results with those of 18 F-FDG PET/CT. Methods: This prospective study analyzed patients with confirmed gastric, liver, or pancreatic malignancies who underwent concurrent 18 F-FDG and 18 F-FAPI-74 PET/CT between June 2022 and December 2022. PET/CT findings were confirmed by histopathology or radiographic follow-up. 18 F-FDG and 18 F-FAPI-74 uptake and tumor-to-background ratios were compared using the Wilcoxon signed-rank test. The McNemar test was used to compare the diagnostic accuracy of the 2 scans. Results: Our cohort consisted of 112 patients: 49 with gastric cancer, 39 with liver cancer, and 24 with pancreatic cancer. Among them, 69 patients underwent PET/CT for initial staging and 43 for recurrence detection. Regarding lesion-based diagnostic accuracy, 18 F-FAPI-74 PET/CT showed higher sensitivity than did 18 F-FDG in the detection of primary tumors (gastric cancer, 88% [22/25] vs. 60% [15/25], P = 0.016; liver cancer, 100% [22/22] vs. 82% [18/22], P = 0.125; pancreatic cancer, 100% [22/22] vs. 86% [19/22], P = 0.250), local recurrence (92% [23/25] vs. 56% [14/25]; P = 0.021), involved lymph nodes (71% [41/58] vs. 40% [23/58]; P < 0.001), and bone and visceral metastases (98% [350/358] vs. 47% [168/358]; P < 0.001). Compared with 18 F-FDG, 18 F-FAPI-74 PET/CT upstaged 17 patients' TNM staging among all treatment-naïve patients (17/69, 25%) and changed the clinical management of 4 patients (4/43, 9%) in whom recurrence or metastases were detected. Conclusion: 18 F-FAPI-74 PET/CT is superior to 18 F-FDG PET/CT in detecting primary tumors, local recurrence, lymph node involvement, and bone and visceral metastases in gastric, pancreatic, and liver cancers, with higher uptake in most primary and metastatic lesions., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Abstract: Septic thrombophlebitis of the portal vein is a serious infectious disorder and is difficult to be diagnosed at an early stage. In this case, we presented 18 F-FDG and 68 Ga-FAPI-46 PET/CT findings in a 45-year-old man with acute appendicitis complicated by septic thrombophlebitis of the portal vein. 68 Ga-FAPI-46 PET/CT showed intense radiotracer uptake in the thrombosis of the portal vein, with higher SUV max and larger disease extent than 18 F-FDG PET/CT. This case demonstrated that 68 Ga-FAPI PET/CT may be a useful imaging modality for the diagnosis of this infectious condition., Competing Interests: Conflicts of interest and sources of funding: This report was sponsored by the National Natural Science Foundation of China (grand number 82071961). None of the authors has any conflict of interest to declare., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

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 68 Ga-FAP-2286 to detect primary and metastatic lesions in patients with various types of cancer, compared with 18 F-FDG and 68 Ga-FAP-2286. Methods: Sixty-four patients with 15 types of cancer underwent 68 Ga-FAP-2286 PET/CT for initial assessment or detection of recurrence. For comparison, 63 patients underwent paired 68 Ga-FAP-2286 and 18 F-FDG PET/CT and 19 patients underwent paired 68 Ga-FAP-2286 and 68 Ga-FAPI-46 PET/CT. Lesion uptake was quantified as SUV max and tumor-to-background ratio. The Wilcoxon matched-pairs signed-rank test was used to compare SUV max between PET modalities, and the McNemar test was used to compare lesion detectability. Results: Uptake of 68 Ga-FAP-2286 was significantly higher than that of 18 F-FDG in primary tumors (median SUV max , 11.1 vs. 6.9; P < 0.001), lymph node metastases (median SUV max , 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 68 Ga-FAP-2286 PET/CT, whereas 9 of the 46 lesions could not be visualized by 18 F-FDG PET/CT. The lesion detection rate of 68 Ga-FAP-2286 PET/CT was superior to that of 18 F-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). 68 Ga-FAP-2286 yielded tumor uptake and lesion detection rates similar to those of 68 Ga-FAPI-46 in a subcohort of 19 patients. Conclusion: 68 Ga-FAP-2286 is a promising FAP-inhibitor derivative for safe cancer diagnosis, staging, and restaging. It may be a better alternative to 18 F-FDG for the cancer types that exhibit low-to-moderate uptake of 18 F-FDG, which include gastric, pancreatic, and hepatic cancers. In addition, 68 Ga-FAP-2286 and 68 Ga-FAPI-46 yielded comparable clinical results., (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)

Abstract: 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. Therefore, the diagnosis of accessory spleen cannot be excluded. Follow-up with 68Ga-exendin-4 PET/CT also showed intense uptake in this nodule, but no significant uptake in the spleen was observed at this time. Therefore, the insulinoma was unmasked from the spleen, excluding the diagnosis of accessory spleen, and allowing curative surgery., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)