Hellenic journal of nuclear medicine最新文献

Objective: Gallium-68 (⁶⁸Ga)-pentixafor, a novel positron emission tomography (PET) tracer with high affinity for C-X-C motif chemokine receptor 4 (CXCR4), has recently been introduced in order to assess the CXCR4 expression status in vivo. This study is to investigate the role of ⁶⁸Ga-pentixafor in detecting various tumors with mice models and to provide references to clinical studies.

Materials and methods: Gallium-68-pentixafor and fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET was performed in opm-2 (lymphoma), daudi (myeloma) and panc1 (pancreatic cancer)-bearing mice. Tumor and background tissue uptake between ⁶⁸Ga-pentixafor and ¹⁸F-FDG PET were compared. Gallium-68-pentixafor PET/computed tomography (CT) was performed in four patients with lymphoma and three patients with multiple myeloma, and ¹⁸F-FDG PET/CT was performed as a reference.

Results: The uptake of ⁶⁸Ga-pentixafor in background tissues including muscle, liver and kidneys were all lower than those of ¹⁸F-FDG. The uptake of ⁶⁸Ga-pentixafor in the tumors of lymphoma and myeloma-bearing xenografts was comparable or higher than those of ¹⁸F-FDG. However, the tumors of panc-1 xenografts had much lower uptake of ⁶⁸Ga-pentixafor than those in lymphoma and myeloma-bearing mice, and it was also significantly lower than those of ¹⁸F-FDG. The high uptake of ⁶⁸Ga-pentixafor in vivo was confirmed by the high expression of CXCR4 in tumors with immunochemical analysis. Gallium-68-pentixafor PET/CT in patients with marginal zone lymphoma (MZL) and myeloma showed more intense uptake and more extensive involvement than ¹⁸F-FDG PET/CT did. Gallium-68-pentixafor and ¹⁸F-FDG PET/CT showed comparable uptake in the patient with follicular lymphoma.

Conclusion: Gallium-68-pentixafor is a promising agent for the evaluation of lymphoproliferative diseases.

Objective: The aim of this study is to determine the importance of different fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography with computed tomography (PET/CT) semi-quantitative and quantitative parameters, as well as various clinical and demographic parameters, in predicting disease outcomes and response to therapy in patients with diffuse large B-cell lymphoma (DLBCL).

Subjects and methods: The study included 64 patients diagnosed with DLBCL who underwent ¹⁸F-FDG PET/CT imaging between January 2020 and April 2023. Each patient underwent both an initial ¹⁸F-FDG PET/CT and an interim ¹⁸F-FDG PET/CT after 2 or 4 cycles of chemotherapy. The Deauville score (DS) was calculated for each patient. Progression-free survival (PFS) was defined as the time from the date of diagnosis to the first appearance of metabolic or morphological progression of pre-existing lesions and/or the appearance of new lesions detected on interim ¹⁸F-FDG PET/CT or follow-up radiological imaging, as well as in cases of death due to the underlying disease or until the end of the clinical follow-up period.

Results: Among the clinical-demographic parameters analyzed, the only significant predictive factor was the international prognostic index (IPI) score, categorized by group. Of the ¹⁸F-FDG PET/CT parameters examined, DS showed strong statistical significance in both univariate and multivariate analyses. While maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak) were statistically significant in the univariate analysis. Progression-free survival was longer in patients with an IPI ≤2 and DS ≤3, compared to those with higher IPI and DS.

Conclusion: The results of this study showed that the early metabolic response to therapy assessed on the basis of interim ¹⁸F-FDG PET/CT is a significant independent predictive factor for disease outcome in patients with DLBCL.

Early detection of mild cognitive impairment (MCI) is crucial for initiating therapeutic interventions that may slow or prevent further cognitive deterioration. Mild cognitive impairment represents a transitional phase between normal cognitive aging and more severe forms of dementia, such as Alzheimer's disease (AD). Positron emission tomography (PET) can provide insight into the pathophysiology and progression of neurodegenerative processes associated with dementia and MCI using either fluorine-18 (¹⁸F)-florbetapir, which detects beta-amyloid plaque burden, or ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG), which measures glucose metabolism. However, there are limited comparative studies using the two radiotracers to quantify cognitive decline. This case study presents an 83-year-old female with a clinical diagnosis of MCI and a mini-mental state examination (MMSE) score of 26, at the lower boundary for normal cognitive function; she was assessed with PET/computed tomography (CT) using both radiotracers. Although global assessments did not reveal significant abnormalities, localized findings showed hypometabolism in key brain regions, such as the posterior cingulate cortex, and beta-amyloid plaque accumulation in the anterior cingulate cortex. These results highlight the limitations of conventional cognitive assessments, like the MMSE, and underscore the potential value of PET imaging as a complementary diagnostic tool. The study supports the role of ¹⁸F-FDG as a stronger indicator of cognitive impairment due to its correlation with cognitive scores, while recognizing the need for further research to evaluate the predictive value of both PET tracers in early MCI detection and their potential to improve diagnostic accuracy.

Thoracic splenosis is the presence of acquired ectopic splenic tissue within the thoracic cavity, typically following thoracoabdominal trauma or surgery. It is mostly asymptomatic and detected incidentally on radiography or tomography. A 64-year-old man was admitted with exertional dyspnea without any other respiratory complaints. The patient had a history of diabetes mellitus and hypertension and had undergone bilateral lung surgery and splenectomy due to a traffic accident 30 years ago. Thoracic computed tomograph (CT) revealed an 11x7mm nodular lesion in the posterobasal lower lobe of the left lung, multiple millimetric nodular lesions in the pleura corresponding to the left lung operation site, a focal defect in the right diaphragm, and liver herniation in this area. The diagnosis of "thoracic splenosis" was made by splenic scintigraphy.

This report presents a case of a 51-year-old woman who was admitted to our hospital with incomplete closure of the left eyelid and a crooked right corner of the mouth. She was diagnosed with multifocal head-neck and liver paragangliomas that were confirmed by pathological tests and gallium-68-fibroblast activation protein inhibitor (⁶⁸Ga-FAPI) positron emission tomography/computed tomography (PET/CT) imaging. The findings of this case suggest that ⁶⁸Ga-FAPI PET/CT may be a potential diagnostic tool for paragangliomas.

Objective: Fibroblast activation protein inhibitor (FAPI) positron emission tomography/computed tomography (PET/CT) was reported to outperform fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT in thyroid cancer in heterogenous patient collectives. This interim analysis of a prospective study aims to determine whether ¹⁸F-FAPI-74 is superior to ¹⁸F-FDG PET/CT in the distinct subgroup of radioactive-iodine (RAI)-refractory differentiated thyroid cancer (DTC).

Subjects and methods: Ten patients with recurrent DTC, detected by elevated thyroglobulin, negative RAI-scan after thyroidectomy and RAI-therapy were prospectively included. All patients underwent ¹⁸F-FAPI-74 and ¹⁸F-FDG PET/CT. The diagnostic performances were compared on a per-patient and per-lesion basis.

Results: Fluorine-18-FAPI-74 PET/CT missed tumour recurrence in one patient. Fluorine-18-FDG PET/CT revealed more metastases in three patients. No management change following ¹⁸F-FAPI-74 PET/CT was documented. On a per-lesion analysis, the quantitative uptake values were significantly higher for ¹⁸F-FDG than ¹⁸F-FAPI-74 in all metastases (¹⁸F-FDG: median tumor to background ratio-TBRmax: 3.05 (1.02-9.55), ¹⁸F-FAPI-74: median TBRmax: 1.09 (0.38-5.09); P<0.001) (¹⁸F-FDG: median TBRmean: 1.71 (0.65-11.53), ¹⁸F-FAPI-74: median TBRmean: 0.64 (0.24-3.20). The detection rate was significantly higher for ¹⁸F-FDG (29/71) compared to ¹⁸F-FAPI-74 PET/CT (13/71, P<0.001).

Conclusion: Fluorine-18-FDG-PET/CT outperforms ¹⁸F-FAPI-74 PET/CT in RAI-refractory DTC in this prospective analysis.

Objective: To analyze the diagnostic value of fluorine-18-fluoro-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in mantle cell lymphoma (MCL) and explore its application in distinguishing between the classic and aggressive variants of MCL.

Subjects and methods: Retrospective analysis was performed on the ¹⁸F-FDG PET/CT imaging, clinical, and pathological data of 134 newly diagnosed MCL patients confirmed by pathology.

Results: Among the 134 patients, 97.8% had increased ¹⁸F-FDG uptake in lymph nodes, and 88.8% had increased ¹⁸F-FDG uptake in extranodal tissues or organs. In the diagnosis of bone marrow infiltration in MCL patients, ¹⁸F-FDG PET/CT has demonstrated a high specificity rate of 86.4% and a limited sensitivity rate of 43.9%. Fluorine-18-FDG PET/CT performs well in diagnosing gastric and intestinal infiltration, with high accuracies of 85.0% and 91.7% respectively. The receiver operating characteristic (ROC) curve analysis revealed that a diagnostic threshold of maximum standardized uptake value (SUVmax) at 10.4 effectively distinguished between the classic and aggressive variants of MCL, achieving a sensitivity of 68.0%, a specificity of 80.7%, and an accuracy of 79.1%, with an area under the curve (AUC) value of 0.771.

Conclusion: Fluorine-18-FDG PET/CT has a high positive detection rate in both intra-nodal and extra-nodal lesions of MCL at initial diagnosis. It exhibits high specificity and positive predictive value (PPV) in diagnosing bone marrow infiltration and possesses strong comprehensive diagnostic capabilities in gastrointestinal infiltration. Furthermore, the SUVmax can be used to distinguish between the classic and aggressive variants of MCL, and it is significantly positively correlated with the Ki-67 index, providing valuable clinical reference.

Objective: Because of low mortality rates and high treatment-related adverse effects in patients diagnosed early, active surveillance, focused treatments, and watchful waiting are currently advocated, emphasizing the importance of proper prostate cancer (Pca) staging using imaging techniques. We aimed to comparatively investigate the success rates of multiparametric prostate magnetic resonance imaging (MRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/MRI in predicting tumoral regions, seminal vesicle invasion, and extraprostatic extension.

Subjects and methods: Twenty six patients with a biopsy diagnosis of prostate cancer who underwent radical prostatectomy between January 2021 and September 2022 were included in the study. Preoperative evaluation was conducted through a combination of multi-parametric (Mp)MR and PSMA PET/MRI. Findings such as tumoral regions, seminal vesicle invasion, and extra-prostatic extension in prostatectomy specimens were compared with the MpMRI and PSMA PET/MRI images.

Results: Prostate cancer was present in 103 foci of a total of 156 segments. In the context of identifying the aforementioned foci, the sensitivity of MpMRI was determined to be 74.8%, coupled with a specificity of 94.3%. Similarly, the sensitivity of PSMA PET/MRI was established at 70.9%, accompanied by a specificity rate of 90.6%. In the prediction of extraprostatic extension, MpMRI exhibited a sensitivity of 33.33% alongside a specificity of 78.57%. In contrast, PSMA PET/MRI displayed a sensitivity of 25% but achieved a higher specificity of 100%. Concerning the prediction of seminal vesicle invasion, MpMRI demonstrated a sensitivity of 40% and a specificity of 95.24%. Conversely, PSMA PET/MRI yielded a sensitivity of 60%, which was slightly superior to MpMRI's sensitivity with a close specificity rate of 95.24%.

Conclusion: MRI and PSMA PET/MRI are reliable methods for the local staging of prostate cancer and the prediction of tumor localization. No statistically significant advantage of either method was discerned in the course of our study.

In the usual scenario, vertebral hemangiomas do not demonstrate heightened uptake above background on fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) scans. Here we presented a case of a positive ¹⁸F-FDG PET/CT result indicating invasive vertebral hemangioma at the L2 vertebra, with atypical CT imaging features of heterogeneous increased density and multiple patchy density shadows. Our case underscores an additional uncommon aspect of invasive vertebral hemangioma imaging, warranting consideration in the differential diagnosis when encountering analogous findings on ¹⁸F-FDG PET/CT.