Clinical Nuclear Medicine最新文献

A 46-year-old woman with primary hyperparathyroidism and negative sestamibi parathyroid scan was referred for 18F-fluorocholine (18F-FCH) positron emission tomography (PET/CT) scan to help localize parathyroid adenoma. FCH PET/CT scan identified a hyperfunctioning parathyroid gland in the left neck. In addition, there was unusually intense unilateral FCH uptake in the right breast corresponding to dense soft tissue. Upon further questioning, the patient admitted to breastfeeding for the past year exclusively from the right breast. Breast MRI showed no corresponding abnormal signal. We present the imaging findings of unilateral breastfeeding on 18F-FCH PET/CT.

Coronary artery involvement in giant cell arteritis (GCA) is rare but can lead to severe complications, including myocardial infarction and death. We present unique 2-[18F]fluorodeoxyglucose positron emission tomography/computed tomography (2-[18F]FDG-PET/CT) findings in a 91-year-old woman with GCA. In addition to typical aortic and supra-aortic involvement, this scan revealed intense FDG uptake in the coronary arteries, including the left main trunk, left anterior descending, circumflex, and right coronary arteries. This inflammatory pattern was consistent with GCA, with no signs of atherosclerosis on coronary CT angiography. Early identification of coronary inflammation enabled timely immunosuppressive therapy, potentially preventing fatal outcomes.

Prostate-specific membrane antigen (PSMA) overexpression on prostate cancer cells finally led to the FDA approval of the therapeutic use of 177Lu-PSMA-617 in metastatic castrate-resistant prostate cancer. However, PSMA is also expressed in the neovasculature of other solid tumors, such as lung and renal cancer, making the theranostic potential of 177Lu-PSMA-617 worth exploring in this setting. Here is such a case of an 83-year-old man with advanced non-small cell lung cancer where the theranostic potential of 177Lu-PSMA-617 was explored using dosimetric analysis.

A 7-year-old boy underwent 18F-FDG PET/CT in the evaluation of a retroperitoneal mass. The examination revealed significant FDG accumulation in the right adrenal region and retroperitoneal lymph nodes, as well as mild FDG uptake in a diaphragmatic lesion. Histopathological analysis of the right adrenal mass was consistent with ganglioneuroblastoma. Three months later, 123I-MIBG scintigraphy was conducted, which did not demonstrate abnormal MIBG accumulation in the diaphragmatic lesion. Histopathological examination of the diaphragmatic lesion confirmed metastatic involvement.

We present a 67-year-old woman with a history of coronary artery bypass graft surgery, who experienced recent chest pain. Myocardial perfusion imaging and 99mTc-FAPI-46 SPECT were performed to assess myocardial infarction. The dynamic FAPI imaging indicated sustained myocardial activity. Myocardial perfusion imaging identified extensive myocardial infarction and ischemia, while FAPI uptake slightly overestimated the infarct extension. Coronary angiography correlated well with these findings. FAPI PET/CT is increasingly being used to monitor cardiac remodeling. This pioneering experience with 99mTc-FAPI-46 showcases comparable results to PET/CT, providing valuable insights into cardiac remodeling processes and highlighting the potential of 99mTc-FAPI-46 in cardiac imaging.

Mixed adenoneuroendocrine carcinoma of the common bile duct is extremely rare. A 72-year-old man presented with jaundice for 1 week. 18F-FDG PET/CT showed intense 18F-FDG uptake in the common bile duct and adjacent lymph node. Finally, postoperative pathology confirmed the diagnosis of mixed adenoneuroendocrine carcinoma of the common bile duct with solitary lymph node metastasis.

Primary renal neuroendocrine tumors are very rare. Herein, we report a case of imaging findings of a renal neuroendocrine tumor in a 36-year-old man. On 68Ga-FAPI-04 PET/CT and 18F-FDG PET/CT, it presented as a renal soft tissue mass with intense FAPI uptake (SUVmax: 20.8) but lower FDG uptake (SUVmax: 9.3). Postsurgical pathology supported a diagnosis of well-differentiated renal neuroendocrine tumor (G2).

Purpose: 68Ga-Pentixafor PET/CT targets CXCR4 receptors and provides superior diagnostic accuracy in multiple myeloma (MM) compared with 18F-FDG PET/CT. However, its role in response evaluation remains unexplored. We propose a 68Ga-Pentixafor PET/CT-based response evaluation criterion and evaluate its utility compared with International Myeloma Working Group (IMWG) criteria and 18F-FDG PET/CT-based response.

Patients and methods: In this prospective single-center study, 40 treatment-naive myeloma patients were recruited between February 2021 and April 2023. Both 68Ga-Pentixafor and 18F-FDG PET/CT were performed at baseline and at follow-up (7.2 mo-median). Response to treatment was evaluated using the proposed 68Ga-Pentixafor PET/CT criteria and compared with responses assessed by IMWG and 18F-FDG PET/CT. Progression-free survival (PFS) and overall survival (OS) were analyzed and compared using Kaplan-Meier survival curves.

Results: Among the 40 newly diagnosed MM patients [median age: 56.5 years (IQR 45.25 to 63.75); 24 men], 68Ga-Pentixafor PET/CT was positive in a greater proportion of patients than 18F-FDG PET/CT [90% (36/40) vs. 67.5% (27/40); P=0.02] thus, adequately evaluated response in additional 27.5% (11/40) of cases. Using the proposed criteria for 68Ga-Pentixafor PET/CT, significant differences in PFS were observed across response categories [complete response (CR)-not reached, partial response (PR)-26.2 mo, progressive disease (PD)-15.3 mo; P=0.001]. Among patients achieving ≥very good partial response (VGPR) as per IMWG, those with positive 68Ga-Pentixafor PET/CT had shorter PFS compared with those with negative findings (median PFS: 34.2 mo vs. not reached; P=0.056), whereas no significant difference was noted with 18F-FDG PET/CT (P=0.68). In addition, on follow-up of patients with negative 18F-FDG at the response, those with discordant 68Ga-Pentixafor findings had significantly shorter PFS (17.73 mo vs. not reached; P=0.010) compared with those with concordant negative findings.

Conclusions: 68Ga-Pentixafor PET/CT offers a more accurate assessment of treatment response and prognosis in MM patients, adding valuable information beyond the IMWG and 18F-FDG PET/CT-based criteria.

Abstract: Autologous fat grafting for cosmetic breast augmentation is becoming increasingly popular. Late complications after intramammary fat injection include fat necrosis, liponecrotic cyst, calcification, and lymphadenopathy. We describe FDG PET/CT findings in a patient with multiple-injection-site fat necrosis after intramammary fat injection. FDG PET/CT showed multifocal activity in the subcutaneous and subglandular regions corresponding to the fat injection sites of the bilateral breasts and multiple FDG-avid lymph nodes of the axillae, mimicking malignancy. Careful correlation with clinical history and familiarity with the imaging findings of the complications after intramammary fat injection are helpful for avoiding misdiagnosis.

Abstract: A 56-year-old man with a history of brain abscess undergoing a 68Ga-labeled prostate-specific membrane antigen (PSMA) ligand PET/CT scan due to rising prostate-specific antigen levels. Besides the uptake of PSMA in the prostate lesion, the 68Ga-PSMA PET/CT images showed significant PSMA uptake in the abscesses in the left parietal and left temporal lobes. This highlights the necessity of cautious interpretation of PSMA PET/CT results, considering alternative diagnoses like infections.