Clinical Nuclear Medicine最新文献

Abstract: Adrenocortical carcinoma (ACC) is a highly aggressive malignancy with high recurrence rates and poor prognosis. There are only limited treatment options with poor response rates. ACCs are documented to express chemokine receptor CXCR4, which can be visualized using 68 Ga-pentixafor PET/CT. We herein present a case of ACC with local recurrence and peritoneal metastases, which was well visualized on FDG and pentixafor PET/CT. The high expression of CXCR4 offers the potential of theranostics and targeted endoradiotherapy in patients with metastatic ACC. We also observed thymic rebound to illustrate mild to moderate grade uptake of 68 Ga-pentixafor in this patient.

Abstract: We present a case of 37-year-old man with multiple masses in the abdominal and pelvic cavity who underwent 18 F-AlF-NOTA-octreotide PET/CT. The masses demonstrated heterogeneously increased uptake on 18 F-AlF-NOTA-octreotide PET/CT and were suggestive of neuroendocrine tumor. However, the histopathological examinations confirmed the masses to be peritoneal mesothelioma. This case indicated that peritoneal mesothelioma should be kept in mind as one of the differential diagnoses for 18 F-AlF-NOTA-octreotide-avid tumors.

Dementia with Lewy bodies (DLB) can be diagnosed through a combination of clinical criteria, the loss of dopaminergic neuron terminals in presynaptic [ 123 I]FP-CIT SPECT dopaminergic imaging, and diffuse [ 18 F]FDG PET hypometabolism, which typically affects also the visual cortex. A 360-degree CZT SPECT systems offer advantages in terms of count sensitivity, and both contrast and energy resolution for perfusion and dopaminergic imaging as compared with conventional SPECT systems. As it happens for PET imaging protocols, a dual-time-window protocol with CZT SPECT imaging was used for a suspected DLB patient to capture both perfusion and dopaminergic states.

Abstract: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, and a sizable fraction of the DLBCL patients presents with advanced, relapsed, and refractory disease, demonstrating poor response to standard chemotherapy regimens. Radioimmunotherapy (RIT) has shown to be clinically effective in refractory DLBCL. We present the case of a patient with DLBCL with [ 18 F]FDG-avid widespread skeletal as well as splenic involvement as poor prognostic extranodal disease on FDG PET/CT. RIT based on [ 177 Lu]Lu-DOTA-rituximab was explored to study the biodistribution and dosimetry of [ 177 Lu]Lu-DOTA-rituximab in CD20-positive lymphoma. An exceptionally high tracer concentration in skeletal and splenic disease was observed, supporting its potential RIT application in relapsed and refractory DLBCL patients in the future.

Abstract: A 75-year-old woman with Takayasu arteritis was referred to 18 F-FDG PET/CT due to elevated C-reactive protein in her laboratory data. FDG PET/CT with semiconductor detectors revealed no uptake in the arterial walls, suggesting active inflammation. However, the blood pool uptake in the proximal portion of the left subclavian artery was defective, suggesting arterial occlusion. Magnetic resonance angiography revealed complete occlusion of the left subclavian artery. Ultrasonography showed the reverse flow of the left vertebral artery. Semiconductor PET can visualize the blood pool defects of the intra-arterial uptake in the arterial branches from the aorta.

Background: We aim to report on somatostatin receptor (SSTR)-targeted molecular imaging and therapy in patients with advanced esthesioneuroblastoma (ENB).

Patients and methods: Five patients with ENB [Kadish stage D in 5/5 (100%); Hyams grade 2 in 2/5 (40%), grade 3 in 2/5 (40%), undetermined in 1/5 (20%)] underwent SSTR-directed PET/CT. We quantified SSTR-avid tumor volume (TV), maximum SUV (SUV max ), and target-to-background ratios (TBR). Based on imaging, peptide receptor radionuclide therapy (PRRT) along with dosimetry was also conducted. We recorded nephrotoxicity and hematotoxicity, including estimated glomerular filtration rate (eGFR), hemoglobin, leukocytes, and thrombocytes at baseline and after the last treatment cycle. We determined adverse events following Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Response and progression-free survival (PFS) was also evaluated.

Results: All 5 patients were rated positive on SSTR-PET/CT. On a lesion-based level, we identified 32 SSTR-avid tumor sites with a median TV of 11.7±10.8 and SUV max of 24.3±12.8. TBR was 19.8±9.7, indicating excellent image contrast. After median 4 (range, 2-6) cycles with a median of 7.7 GBq per cycle per patient, we observed no CTCAE grade 3 or 4 toxicity for leukocytes and thrombocytes and no significant CTCAE events for renal function. One patient (20%), however, developed reversible grade 3 anemia. Up to 11.8 Gy in tumor lesions were achieved. Partial response was recorded in 3/5 (60%), stable disease in 1/5 (20%), and progressive disease in 1/5 (20%). The median PFS was 29 weeks.

Conclusions: SSTR-directed PET provided high image contrast in ENB, suggesting good read-out capabilities in this tumor type. PRRT was also feasible, along with an acceptable safety profile, thereby rendering SSTR-targeted theranostics a potential treatment option in advanced disease.

Thyroid tuberculosis is a rare condition that is difficult to diagnose and may be suspected of being a malignant tumor. We report a case of thyroid tuberculosis in a 54-year-old woman that mimicked thyroid cancer on ultrasound, with a 18 F-FAPI PET/CT scan showing intense 18 F-FAPI uptake in the thyroid lobe, right neck lymph node, and celiac lymph nodes.

Abstract: An 18 F-FDG PET/CT was conducted on a 44-year-old man with a history of dermatomyositis and avascular necrosis of left femoral head, due to a fever of unknown origin. The scan revealed patchy and cloudy high densities within the medullary cavities of bilateral distal femur and proximal tibia, exhibiting peripheral high 18 F-FDG avidity. Subsequent MRI confirmed bone infarction.

A 53-year-old woman was found to have a soft tissue mass in the right lower lung lobe on chest CT, raising suspicion of lung cancer. For staging, 18 F-FDG PET/CT was performed, which demonstrated intense tracer uptake in the mass (SUV max , 14.6). Subsequently, surgical excision was undertaken, and histopathological examination of the resected specimen confirmed the diagnosis of a schwannoma.

Abstract: A 13-year-old girl presented with dysphagia underwent contrast-enhanced CT and endoscopy. The CT revealed cervical esophageal wall thickening with heterogeneous enhancement. Microscopic examination of the biopsy specimen suggested a possible mesenchymal tumor. She underwent an 18 F-FDG PET/CT scan for staging. The scan showed local thickening of the cervical esophageal wall with heterogeneous and significantly elevated FDG activity. Subsequent immunohistochemical staining and fluorescence in situ hybridization confirmed the diagnosis of esophageal inflammatory myofibroblastic tumor.