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.

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.

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.

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.

Comparison of the Relative Diagnostic Performance of [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT for the Detection of Bone Metastasis in Patients With Different Cancers.

PURPOSE: The present retrospective analysis sought to compare the relative diagnostic efficacy of [68Ga]Ga-DOTA-FAPI-04 to that of [18F]FDG PET/CT as a means of detecting bone metastases in patients with a range of cancer types. MATERIALS: In total, 30 patients with bone metastases associated with different underlying malignancies were retrospectively enrolled. All patients had undergone [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT, and the McNemar test was used to compare the relative diagnostic performance of these two imaging modalities. The maximum standard uptake value (SUVmax) was used to quantify radiotracer uptake by metastatic lesions, with the relative uptake associated with these two imaging strategies being compared via the Mann-Whitney U test. The cohort was further respectively divided into two (osteolytic and osteoblastic bone metastases) and three clinical subgroups (lung cancer, thyroid cancer, and liver cancer). RESULTS: [68Ga]Ga-DOTA-FAPI-04 PET/CT was found to be significantly more sensitive as a means of diagnosing bone metastases relative to [18F]FDG PET/CT ([109/109] 100% vs [89/109] 81.7%; P< 0.01), consistent with the significantly increased uptake of [68Ga]Ga-DOTA-FAPI-04 by these metastatic lesions relative to that of [18F]FDG (n=109, median SUVmax, 9.1 vs. 4.5; P< 0.01). [68Ga]Ga-DOTA-FAPI-04 accumulation was significantly higher than that of [18F]FDG in both osteolytic (n=66, median SUVmax, 10.6 vs 6.1; P < 0.01), and osteoblastic metastases (n=43, median SUVmax, 7.7 vs 3.7; P < 0.01). [68Ga]Ga-DOTA-FAPI-04 uptakes were significantly higher than that of [18F]FDG in bone metastases from lung cancer (n = 62, median SUVmax, 10.7 vs 5.2; P < 0.01), thyroid cancer (n = 18, median SUVmax, 5.65 vs 2.1; P < 0.01) and liver cancer (n = 12, median SUVmax, 5.65 vs 3.05; P < 0.01). However, [68Ga]Ga-DOTA-FAPI-04 detected 10 false-positive lesions, while only 5 false-positive were visualized by [18F]FDG PET/CT. CONCLUSION: [68Ga]Ga-DOTA-FAPI-04 PET/CT exhibits excellent diagnostic performance as a means of detecting bone metastases, and is superior to [18F]FDG PET/CT in this diagnostic context. Furthermore, [68Ga]Ga-DOTA-FAPI-04 tracer uptake levels are higher than those of [18F]FDG for most bone metastases. However, owing to the potential for false-positive bone lesions, it is critical that physicians interpret all CT findings with caution to ensure diagnostic accuracy.

Detection of Nasal Solitary Extramedullary Plasmacytoma on 18F-FDG PET/CT Imaging.

ABSTRACT: A 46-year-old man presented with a 3-month history of epistaxis. CT and MRI scan showed a soft tissue mass in the left nasal cavity. An excisional biopsy of the mass revealed extramedullary plasmacytoma. 18F-FDG PET/CT showed intense activity in the region of the left nasal cavity but no other FDG-avid lesions. Additional workups did not reveal any evidence of systematic disease. Based on these findings, the patient was diagnosed as having solitary nasal extramedullary plasmacytoma. He received the local radiation therapy. During the 3-month follow-up, his symptom was relieved.

Pancreatitis, Panniculitis, and Polyarthritis Syndrome Detected on 99mTc-MDP Bone Scan.

ABSTRACT: Pancreatitis, panniculitis, and polyarthritis syndrome is a rare disease. A 49-year-old man recently complained of bilateral ankle and epigastric pain. An ankle x-ray showed subcutaneous soft tissue swelling. Subsequent 99mTc-MDP bone scan showed foci of abnormal activity around joints in all extremities, especially in the knees and ankles. In addition, multiple nodular calcifications in the head of the pancreas were found in the abdominal CT scan. The patient also had increased blood amylase and lipase. The symptoms were resolved after the treatment of his pancreatitis.