Clinical Nuclear Medicine最新文献

Abstract: 68 Ga-pentixafor uptake in hemangioma is rare. We report 68 Ga-pentixafor PET/MRI findings of a hepatic hemangioma in a 54-year-old woman. The images revealed a hyperintense lesion in the right posterior liver on T2-weighted images, with mild pentixafor uptake. The lesion was consistent with typical presentations of a hemangioma on MRI and contrast-enhanced CT.

Abstract: Leukemia spread in the bone marrow typically is greater in the axial skeleton than in the appendicular skeleton. We report an unusual pattern of FDG-avid bone marrow infiltration that is more prominent in the appendicular skeleton than the axial skeleton in a pediatric patient with B-cell acute lymphoblastic leukemia.

Abstract: A 61-year-old man with a medical history of human immunodeficiency virus well controlled on antiretroviral therapy presented for distal sensorimotor symptoms, fatigue, and recurrent fevers. Erythrocyte sedimentation rate and C-reactive protein were both elevated. Antineutrophilic cytoplasmic antibody and antinuclear antibodies were negative. Neurologic imaging workup was unremarkable. 18 F-FDG PET/CT, which was crucial for diagnosis, demonstrated pathological tracer activity throughout the medium-sized vessels with sparing of the aorta. In view of presentation, comorbidities, and imaging findings, polyarteritis nodosa was diagnosed. The patient was treated appropriately with steroids and cyclophosphamide with significant symptomatic improvement.

Abstract: Hepatic pseudolesions are relatively frequent in contrast-enhanced CT or MR images, attributable to the unique intrahepatic hemodynamics. It is also well documented that focal liver uptake can result from unusual collateral circulation on radionuclide liver scans. This report presents a case of sectorial hepatic hypermetabolism identified via FDG PET/CT, correlating with areas of increased attenuation in the liver observed on contrast-enhanced chest CT in a patient with lung cancer complicated by superior vena cava obstruction. Notably, the nonphysiological hypermetabolic activity was resolved on subsequent FDG PET/CT imaging conducted 2 days later, following alteration of the tracer injection route.

Abstract: A 43-year-old woman presented with an anorectal mass at which time excision was performed, and biopsy revealed anorectal mucosal melanoma (AM), anal subtype. Postexcision, 18F-FDG PET/CT identified residual melanoma, confirmed on biopsy. Recurrence was monitored every 3 months using 18F-FDG, which identified a perirectal lymph node 2.5 years later positive for metastatic melanoma. Given the rarity of AM and often delayed diagnosis, patients often present with metastases, resulting in poor prognosis. This unique case of metastatic AM with prolonged survival of 7 years to date supports the implementation of 18F-FDG in the diagnostics and monitoring of AM.

Abstract: In the evolving landscape of precision oncology, this review delineates the role of radiopharmaceuticals targeting the norepinephrine transporter (NET), with a particular focus on the current clinical application of 123I-MIBG diagnostic imaging and 131I-MIBG therapeutics, in particular for pheochromocytoma, neuroblastoma, or paraganglioma. We will also highlight recently introduced 18F-labeled NET targeting imaging radiotracers, which would offer unparalleled resolution, enhanced tumor localization, and staging properties. Complementing these novel second-generation PET agents in a theranostic approach, astatine-211 meta-astatobenzylguanidine (211At-MABG) would leverage the advantages of alpha-particles to selectively target and eradicate NET-expressing tumor cells with minimal off-target effects.

Abstract: Castleman disease is a rare lymphoproliferative disorder primarily affecting lymph nodes, including unicentric and multicentric types. The multicentric form is rarer and can often be misdiagnosed as lymphoma. Here, we report 18F-FDG and 68Ga-pentixafor PET/CT findings in a case of Castleman disease involving the nasopharynx and multiple lymph nodes.

Abstract: A 20-year-old man with papillary thyroid cancer received a fourth radioiodine regimen to treat 131I-avid lung metastases. Posttherapeutic whole-body scan revealed focal radioiodine uptake on the anterior region of the left lower limb that was not visible on previous whole-body scan and which suggested skin contamination. Visual examination of the left leg evidenced a posttraumatic scab caused by a fall 2 weeks before. Skin metastasis was ruled out. 131I SPECT/CT acquisition ruled out bony uptake and confirmed that the skin uptake was related to the superficial scab.

Abstract: Hyperpolarized 1-13C-pyruvate magnetic resonance spectroscopy (MRS) and MRS imaging (MRSI) offer noninvasive and real-time direct assessment of the altered metabolism of cancer cells known as the Warburg effect-a key hallmark of cancer. When combined with simultaneously acquired 18F-FDG PET in a PET/MR scanner, coined hyperPET by us, this dual-modality may unveil cancer-type specific glucose metabolic phenotypes with potential implications for patient prognostication, treatment-response assessment, and prediction. We here present the first human data of simultaneously acquired hyperpolarized MRS/MRSI and PET performed in a PET/MR scanner-and the first human hyperpolarized MRS/MRSI data from a patient with lymphoma.

Purpose: Modifying glucagon-like peptide-1 receptor (GLP-1R)-targeted PET agent to achieve faster renal clearance and preserved high affinity to GLP-1R is clinically relevant. The aim of this study is to assess the performance of a newly developed GLP-1R-targeted agent, 68 Ga-HBED-CC-exendin-4 in localizing insulinoma, and its biodistribution, as compared with previously introduced 68 Ga-NOTA-exendin-4.

Patients and methods: Nineteen patients with endogenous hyperinsulinemic hypoglycemia were enrolled and referred for 68 Ga-HBED-CC-exendin-4 PET/CT and 68 Ga-NOTA-exendin-4 PET/CT within 2 consecutive days. Diagnostic performance of the 2 tracers in localizing insulinoma was evaluated, and SUV of the lesion, normal pancreas background, kidneys, and bladder were measured.

Results: 68 Ga-HBED-CC-exendin-4 and 68 Ga-NOTA-exendin-4 PET/CT exhibited an equivalent efficacy in detection rate (both sensitivity of 100%). Although SUV max of the tumor in 68 Ga-HBED-CC-exendin-4 was significantly lower than that in 68 Ga-NOTA-exendin-4 (20.01 ± 9.41 vs 31.78 ± 15.46, P < 0.001) at 50 minutes postinjection, there was no significant difference in the tumor-to-background ratio between the 2 agents (8.61 ± 3.57 vs 8.18 ± 3.38, P = 0.326), and the lesions could be visible as early as 4 minutes postinjection for both agents in patients who underwent dynamic PET/CT. In addition, 68 Ga-HBED-CC-exendin-4 exhibited approximately 30% decrease of the renal accumulation compared with 68 Ga-NOTA-exendin-4 (SUV mean , 42.21 ± 5.79 vs 58.58 ± 10.06 at 50 minutes, P < 0.001).

Conclusions: 68 Ga-HBED-CC-exendin-4 is an effective agent for localizing insulinoma showing similar detectability and tumor-to-background ratio compared with 68 Ga-NOTA-exendin-4. Notably, 68 Ga-HBED-CC-exendin-4 exhibits significantly lower renal uptake than 68 Ga-NOTA-exendin-4, which might potentially benefit the detection of the tumors adjacent to the left kidneys.