Preoperative prediction of pancreatic neuroendocrine tumor grade based on 68Ga-DOTATATE PET/CT.

OBJECTIVE: To establish a prediction model for preoperatively predicting grade 1 and grade 2/3 tumors in patients with pancreatic neuroendocrine tumors (PNETs) based on 68Ga-DOTATATE PET/CT. METHODS: Clinical data of 41 patients with PNETs were included in this study. According to the pathological results, they were divided into grade 1 and grade 2/3. 68Ga-DOTATATE PET/CT images were collected within one month before surgery. The clinical risk factors and significant radiological features were filtered, and a clinical predictive model based on these clinical and radiological features was established. 3D slicer was used to extracted 107 radiomic features from the region of interest (ROI) of 68Ga-dotata PET/CT images. The Pearson correlation coefficient (PCC), recursive feature elimination (REF) based five-fold cross validation were adopted for the radiomic feature selection, and a radiomic score was computed subsequently. The comprehensive model combining the clinical risk factors and the rad-score was established as well as the nomogram. The performance of above clinical model and comprehensive model were evaluated and compared. RESULTS: Adjacent organ invasion, N staging, and M staging were the risk factors for PNET grading (p < 0.05). 12 optimal radiomic features (3 PET radiomic features, 9 CT radiomic features) were screen out. The clinical predictive model achieved an area under the curve (AUC) of 0.785. The comprehensive model has better predictive performance (AUC = 0.953). CONCLUSION: We proposed a comprehensive nomogram model based on 68Ga-DOTATATE PET/CT to predict grade 1 and grade 2/3 of PNETs and assist personalized clinical diagnosis and treatment plans for patients with PNETs.

Imaging findings and clinical relevance of 68Ga-Pentixafor PET in atherosclerosis: a systematic review.

OBJECTIVE: We aimed to perform a qualitative synthesis of evidence on the role of 68Ga-Pentixafor PET in atherosclerosis. METHODS: A systematic search of the PubMed and Embase databases for studies reporting the evaluation of atherosclerotic lesions by 68Ga-Pentixafor PET was performed with a search time frame from database creation to 2022-12-26. The diagnostic test evaluation tool QUADAS-2 was used to evaluate the quality of the included literature and to perform descriptive analyses of relevant outcome indicators. RESULTS: A total of 6 studies with 280 patients were included. One study reported only imaging outcome metrics, while the other five studies reported imaging outcome metrics and clinical correlation metrics. For imaging outcomes, three studies reported imaging results for 68Ga-Pentixafor PET only, and the other three studies reported imaging results for comparative analysis of 68Ga-Pentixafor PET with 18F-FDG PET. For clinical correlation, three studies reported the correlation between tracer uptake and cardiovascular risk factors, one study reported the correlation between tracer uptake and plaque calcification, and one study reported the correlation between all three: tracer uptake, cardiovascular risk factors, and plaque calcification. CONCLUSION: 68Ga-Pentixafor PET has a good imaging effect on atherosclerotic lesions, and it is a promising imaging modality that may replace 18F-FDG PET for atherosclerosis imaging in the future. In patients with atherosclerosis, there is a clear clinical correlation between cardiovascular risk factors, tracer uptake, and plaque calcification.

Increased 68 Ga-FAPI Activity in Hepatic Inflammatory Myofibroblastoma.

ABSTRACT: Hepatic inflammatory myofibroblastoma is an uncommon borderline tumor. We present 68 Ga-FAPI PET/CT findings of hepatic inflammatory myofibroblastoma in a 58-year-old man. The rare hepatic inflammatory myofibroblastoma demonstrated intense tracer uptake on 68 Ga-FAPI PET/CT. This case demonstrates the potential value of 68 Ga-FAPI PET/CT for the evaluation of hepatic inflammatory myofibroblastoma.

Comparison of 68 Ga-DOTATATE PET/CT and 68 Ga-Pentixiafor PET/CT Imaging in a Case of Merkel Cell Carcinoma.

ABSTRACT: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma with a high rate of metastasis and mortality. We present 68 Ga-DOTATATE PET/CT and 68 Ga-pentixiafor PET/CT findings of MCC in a 62-year-old man. Both 68 Ga-DOTATATE PET/CT and 68 Ga-pentixiafor PET/CT revealed increased radioactive uptake of lesions in the scan range. Compared with 68 Ga-DOTATATE PET/CT, the lesions showed higher uptake in 68 Ga-pentixiafor PET/CT. Our case showed that 68 Ga-pentixiafor might be a promising radiotracer in the evaluation of MCC.

68Ga-FAPI PET/CT Imaging of Intracranial Syphilitic Gumma: Comparison to 18F-FDG PET/CT.

ABSTRACT: Intracranial syphilitic gumma is a rare neurological disease. We present 68Ga-DOTA-FAPI-04 and 18F-FDG PET/CT findings of intracranial syphilitic gumma in a 46-year-old man with HIV. In this case, 68Ga-DOTA-FAPI-04 PET/CT outperforms 18F-FDG in helping to visualizing syphilitic gumma. Syphilitic gumma can also cause increase FAPI activity. Our findings suggest the potential value of 68Ga-DOTA-FAPI-04 in the diagnosis of syphilis.

68Ga-FAPI-04 PET/CT in the Detection of Non-FDG-Avid Solid Pseudopapillary Neoplasm of the Pancreas.

ABSTRACT: Solid pseudopapillary neoplasm of the pancreas is a rare tumor. A 46-year-old woman presented with chest pain for 6 months. Chest CT revealed a large mass of the right mediastinum. Then, she underwent 18F-FDG and 68Ga-FAPI-04 PET/CT scans for staging. However, we accidentally found that a non-FDG focus nodule in the body of the pancreas with elevated FAPI activity. Finally, biopsy of the nodule in the body of the pancreas confirmed the diagnosis of solid pseudopapillary neoplasm.

Efficacy and safety of 177Lu-DOTATATE targeted therapy in advanced/metastatic pulmonary neuroendocrine tumors: A systematic review and meta-analysis.

Objective: To perform a meta-analysis of the efficacy and safety about 177Lu-DOTATATE therapy for advanced/metastatic pNETs based on the current clinical evidence. Methods: This systematic review follows the PRISMA guideline. Search PubMed, Medline, EMBASE and CNKI, VIP, Wanfang databases, from establishment to June 2022, on the study of 177Lu-DOTATATE for advanced/metastatic pNETs, the primary endpoint was to evaluate the treatment effect through DRRs and DCRs. Secondary endpoint included assessment of OS, PFS, and treatment-related adverse events across all studies. Two researchers conducted literature screening, data extraction and quality evaluation according to the inclusion and exclusion criteria. Meta-analysis was performed using stata16.0 software, and the data were merged and displayed using forest graphs. Results: A total of 5 studies, 174 patients, on 177Lu-DOTATATE for advanced/metastatic pNETs were included. The pools of DRRs and DCRs were 24% (95% CI: 15%~32%) and 77% (95% CI: 62%~92%), respectively. The pool of OS was 48.78 months (95% CI: 41~56.57 months) and the pool of PFS was 21.59 months (95% CI: 17.65~25.53 months). In all studies, the most common side effect of treatment was hematological toxicity. In 174 patients, hematological toxicity of grade III accounted for 4.0% (7/174), and only 4.0% (7/174) and 1.0% (2/174) of patients had mild nephrotoxicity and hepatotoxicity. Gastrointestinal adverse reactions in 3% (6/174), nausea in 2% (3/174), superior vena cava occlusion in 0.5% (1/174). Conclusion: 177Lu-DOTATATE is effective and safe for advanced/metastatic pNETs, which can delay the progression of the disease, may improve patients' survival, and has low treatment-related toxicity and high safety. However, its efficacy and safety need to be further evaluated in high-quality, multicenter randomized controlled trials in the future. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022344436.

A systematic review of [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT in the diagnostic value of malignant tumor bone metastasis.

Objective: This study aims to perform a systemic analysis of [68Ga]Ga-DOTA-FAPI-04 positron emission tomography (PET)/computerized tomography (CT) and [18F]FDG PET/CT for the diagnosis of malignant tumor bone metastasis based on existing clinical evidence. Methods: This systematic review followed the guidelines of the Preferred Reporting Project (PRISMA) for systematic reviews and meta-analysis. This is a retrospective study of articles published in PubMed. Embase was searched online from the start of May 2022. The main endpoints were the maximum standardized uptake value and the tumor-to-background ratio to determine the examination performance of [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG for bone transfer stoves. Based on the entry and discharge standards, two researchers extracted documents and data and then performed the quality evaluation. Results: A total of eight studies on the metastasis of malignant tumors on bone were included, which involved 358 patients in the final analysis. Conclusion: [68Ga]Ga-DOTA-FAPI-04 showed better detection performance for bone metastasis. The sensitivity of [68Ga]Ga-DOTA-FAPI-04 for the diagnosis of the primary tumor was higher than that of [18F]FDG, whereas the specificity of [18F]FDG was higher than that of [68Ga]Ga-DOTA-FAPI-04. However, further randomized controlled trials and prospective clinical trials are warranted to compare the diagnostic performance of [68Ga]Ga-DOTA-FAPI-04 PET/CT and [18F]FDG PET/CT. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022313019).

Comparison of 68Ga-FAPI and 18F-FDG PET/CT in the Evaluation of Patients With Newly Diagnosed Non-Small Cell Lung Cancer.

Purpose: Several studies have demonstrated that 68Ga-FAPI PET/CT shows high intratumoral tracer uptake and low normal tissue uptake, allowing for excellent visualization of cancer. The purpose of this study was to compare the ability of 68Ga-FAPI and 18F-FDG PET/CT for the evaluation of newly diagnosed NSCLC. Materials and Methods: A prospective analysis of 28 individuals with histopathologically newly confirmed NSCLC that underwent 68Ga-FAPI and 18F-FDG PET/CT was conducted. The performance of two imaging modalities was compared based upon visual assessment, rates of cancer detection, and semi-quantitative parameters (target-to-background ratio [TBR], maximum standard uptake value [SUVmax]) for both primary tumors and metastases. Results: In total, this study enrolled 28 participants (13 male, 15 female; median age: 60.5 years, range: 34 - 78 years. For primary tumors, 68Ga-FAPI and 18F-FDG PET/CT have similar detection performance (28 vs. 27). However, 68Ga-FAPI PET/CT was found to more effectively evaluate most metastases as compared to 18F-FDG PET/CT. 68Ga-FAPI PET/CT detecting more metastases present within the lymph nodes (53 vs. 49), pleura (8 vs. 7), liver (4 vs. 1), and bone (41 vs. 35). The SUVmax and TBR values for 68Ga-FAPI were substantially superior to those for 18F-FDG in lymph node, pleural, and bone metastases. While the SUVmax for these two imaging approaches was comparable for hepatic metastases, 68Ga-FAPI exhibited a significantly higher TBR in relation to that of 18F-FDG. In addition, 68Ga-FAPI PET/CT demonstrates excellent N (80% [8/10]) and M (92.9% [26/28]) staging accuracy in NSCLC patients. Conclusions: 68Ga-FAPI PET/CT as an examination modality is excellent for evaluation of newly diagnosed NSCLC. 68Ga-FAPI PET/CT improves the detection rates of most metastases and facilitating the superior staging of patients with newly diagnosed NSCLC, relative to that achieved by 18F-FDG PET/CT.

Elevated 68 Ga-FAPI Uptake by Primary Benign Intraosseous Meningioma.

ABSTRACT: Intraosseous meningioma is an extremely rare benign tumor. We present the 68 Ga-fibroblast activation protein inhibitor (FAPI) PET/CT findings of primary intraosseous meningioma in a 71-year-old woman. 68 Ga-FAPI PET/CT revealed an intraosseous mass in the right parietal bone with increased FAPI activity. Primary skull malignancy was suspected. However, pathological examination after resection of the mass in the right parietal bone confirmed the diagnosis of benign meningioma (WHO I). A final diagnosis of benign intraosseous meningioma was made.

Comparison of 68Ga-FAPI and 18F-FDG PET/CT in Dermatofibrosarcoma Protuberans.

ABSTRACT: Dermatofibrosarcoma protuberans is a rare soft tissue sarcoma with a high recurrence rate. Herein, we present 68Ga-FAPI and 18F-FDG PET/CT findings of dermatofibrosarcoma protuberans in a 45-year-old man. Dermatofibrosarcoma protuberans only shows limited FDG uptakes on 18F-FDG PET/CT, but demonstrated intense tracer uptakes on 68Ga-FAPI PET/CT. In this case, 68Ga-FAPI was superior to 18F-FDG PET/CT in detecting dermatofibrosarcoma protuberans.

Intense 68Ga-FAPI Uptake in a Patient With Myositis Ossificans: Mimicking Bone Malignancy.

ABSTRACT: A 72-year-old man presented with right hip pain, difficulty in walking, and a mass in his right hip for 3 months. CT suggested osteonecrosis of the right femoral head and a mass in the right hip with calcification. A malignancy was suspected, and the patient was subsequently enrolled in the clinical trial of 68Ga-FAPI. 68Ga-FAPI PET/CT showed a mass in his right hip with intense FAPI activity. It was also highly suggestive of malignancy. The pathological examination after right-hip surgery confirmed the diagnosis of myositis ossificans.

Schmorl Node Can Cause Increased 68Ga-FAPI Activity on PET/CT.

ABSTRACT: 68Ga-FAPI is a newly developed tumor imaging agent with promising clinical applications. However, benign lesions may also show increased FAPI activity. We accidentally discovered that Schmorl node expressed FAPI activity in a patient with sweat gland cancer. Thus, greater awareness is needed that Schmorl nodes are a potential reason for false-positive uptake on 68Ga-FAPI PET/CT.

Efficacy and Safety of 225Ac-PSMA-617-Targeted Alpha Therapy in Metastatic Castration-Resistant Prostate Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVE: To conduct a meta-analysis of the efficacy and safety of 225Ac-PSMA-617 in the treatment of metastatic castration-resistant prostate cancer based on existing clinical evidence. METHODS: Search for retrospective studies about 225Ac-PSMA-617 in the treatment of metastatic castration-resistant prostate cancer from establishment to July 2021 in PubMed and EMBASE. The primary endpoint was 225Ac-PSMA-617 biochemical response evaluation criteria after treatment [any prostate specific antigen (PSA) decrease and PSA decrease >50% from baseline] to evaluate the treatment effect. Secondary endpoints included assessment of overall survival (OS), progression-free survival (PFS), molecular response, and toxicity for all studies. Two researchers conducted literature screening, data extraction and quality evaluation according to the inclusion and exclusion criteria. Use stata16.0 software for analysis, fixed-effects model for data merging and forest plots for display. RESULTS: A total of 6 retrospective studies, namely, 201 patients, were included in the final analysis. The pooled proportions of patients with decreased PSA and PSA decreased by more than 50% were 87.0% (95% confidence interval, 0.820 to 0.920) and 66.1% (95% confidence interval, 0.596 to 0.726), respectively. The pooled proportions of OS and PFS were 12.5 months (95%CI: 6.2-18.8 months) and 9.1 months (95%CI: 2.6-15.7 months). The patients showing molecular responses were 54% (95% confidence interval: 25-84%). In all studies, the most common side effect of 225Ac-PSMA-617 TAT was xerostomia, with any degree of xerostomia occurring in 77.1% (155 out of 201), and grade III only accounted for 3.0%. The second was 30.3% (61 out of 201) anemia of any degree, and grade III accounts for 7.5% (15 out of 201). Grade III leukopenia and thrombocytopenia were 4.5% (9 out of 201) and 5.5% (11 out of 201), respectively. Only 6 (3.0%) of 201 patients had Grade III nephrotoxicity. CONCLUSION: 225Ac-PSMA-617 is an effective and safe treatment option for mCRPC patients, and the toxicity caused by it is relatively low. However, future randomized controlled trials and prospective trials are required in the future to judge the therapeutic effects and survival benefits compared with existing clinical treatments. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42021281967.

Progressive Multifocal Leukoencephalopathy Mimicking Malignancy on 68Ga-FAPI PET/CT: Potential Advantages of FAPI.

ABSTRACT: A 43-year-old man presented with weakness in his right upper limb for 2 months. Head MRI showed intracranial multiple abnormal signal foci. Malignancy was suspected. The patient was subsequently enrolled in the clinical trial of 68Ga-FAPI PET/CT. 68Ga-FAPI PET/CT showed intracranial multiple FAPI-avid foci. It was also highly suggestive of malignancy. However, the combination of clinical manifestations, imaging findings, cerebral spinal fluid examinations, and effective immunotherapy confirmed the diagnosis of progressive multifocal leukoencephalopathy. 68Ga-FAPI may have potential advantages in the diagnosis of progressive multifocal leukoencephalopathy.

Bone Tuberculous Granulomatous Inflammation Mimicking Malignancy on 68Ga-FAPI PET/CT.

ABSTRACT: A 50-year-old woman presented with back pain for 1 month. Chest CT showed osteolytic destruction of T6 vertebral body. A malignancy was suspected. The patient was subsequently enrolled in the clinical trial of 68Ga-FAPI PET/CT. 68Ga-FAPI PET/CT revealed multiple bone destruction with increased FAPI activity. It was also highly suggestive of malignancy or metastases. However, pathological examination after T6 vertebral surgery confirmed the diagnosis of tuberculous granulomatous inflammation.