Hellenic journal of nuclear medicine最新文献

A 70-year-old male patient who presented with persistent upper abdominal pain was found to have a rare case of sclerosing liposarcoma with rib involvement. Despite the absence of significant weight loss or a history of infectious disease, elevated inflammatory markers suggested an underlying inflammatory or neoplastic process. Diagnostic imaging by computed tomography (CT) and single photon emission computed tomography (SPECT) played a critical role in identifying a soft tissue mass causing osteolytic damage to the left 9^th rib. The rapid enlargement of the lesion and the specific imaging characteristics challenged conventional detection methods. Biopsy confirmed the diagnosis of low-grade sclerosing liposarcoma. This case highlights the range of abilities of current imaging modalities in detecting certain forms of liposarcoma and emphasizes the need for a comprehensive diagnostic approach that integrates clinical findings, radiology, and pathology to accurately diagnose and manage such complex cases.

Hereditary transthyretin amyloidosis (hATTR) is considered a rare disease. This is precisely why there are cases of undiagnosed transthyretin amyloidosis, in patients present with restrictive cardiomyopathy, with or without neurological or other symptoms. There are cases of incidental detection of hATTR in patients with cardiac or neurological symptoms using whole-body scintigraphy with diphosphonates. In this paper, we present the accidental detection of hATTR in a 65-year-old patient with neurological and cardiac symptoms, who was referred for skeletal scintigraphy with skeletally avid radiopharmaceuticals due to skeletal pain of unknown origin. Significantly increased uptake of radiopharmaceuticals in the myocardium was observed, corresponding to a Perugini score of 3, with semi-quantification of the heart/contralateral lung fixation ratio (H/CL) of 2.6 in the second hour after radiopharmaceutical application. Ultrasound of the heart was in favor of concentric cardiomyopathy. Due to the high suspicion of hATTR, a genetic test was performed, which showed a pathological mutation of the gene for transthyretin. Hereditary hTTR is probably a more common disease than reported in the literature. Using hATTR detection algorithms and raising awareness of the possible existence of this disease, timely diagnosis using scintigraphy with bone avid radiopharmaceuticals and appropriate therapy can help patients and their close relatives.

Objective: Gallium-68-labeled fibroblast activating protein inhibitor (⁶⁸Ga-FAPI) has been developed for positron emission tomography (PET) and proved to be a promising imaging agent. It has shown good diagnostic performance in the diagnosis of various solid tumors, including head and neck cancers (HNC). This study conducted a meta-analysis on the diagnostic performance of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) and ⁶⁸Ga-FAPI in HNC, summarized the clinical evidence of ⁶⁸Ga-FAPI for HNC, and compared the diagnostic sensitivity of the two imaging agents in the primary and metastatic lesions of HNC.

Materials and methods: PubMed/ Medline, Embase and Cochrane Library databases were searched from built to 31 January 2023. Studies on patients with HNC underwent paired ¹⁸F-FDG and ⁶⁸Ga-FAPI were included. Literature screening, full text review and data extraction were performed by 2 investigators. The risk of bias was examined with the QUADAS-2 tool. Meta-analysis of diagnostic test sensitivity was performed by a random-effect model and displayed by a forest plot.

Results: A total of 507 studies were comprehensively retrieved, and 11 studies, 297 patients were selected for the systematic review and 9 studies for meta-analysis. Two hundred and nine patients selected for initial staging and 88 patients for recurrence. Pooled sensitivity at initial stage was conducted. Based on primary lesions, the sensitivity were ¹⁸F-FDG 0.95 (0.81-0.99) vs ⁶⁸Ga-FAPI 0.99 (0.90-1.00). For lymph node metastases, based on patients, the sensitivity were ¹⁸F-FDG 0.99 (0.77-1.00) vs ⁶⁸Ga-FAPI 0.92 (0.68-0.98); For distant metastases, based on patients, the sensitivity were ¹⁸F-FDG 0.82 (0.03-1.00) vs ⁶⁸Ga-FAPI 0.92 (0.59-0.99).

Conclusion: Gallium-68-FAPI has great potential in the diagnosis of HNC and has similar diagnostic value with ¹⁸F-FDG. While there is much overlap in the performance (as measured by sensitivity) of these two agents but a trend may favor ⁶⁸Ga-FAPI over ¹⁸F-FDG for detection of primary tumor and distant metastases. Therefore, in the diagnosis and evaluation of head and neck cancers, the combination of ⁶⁸Ga-FAPI and ¹⁸F-FDG can be considered according to the individual situation.

Objective: Radiolabeling of nanoparticles has potential benefits for personalized treatments and theranostic applications, which have been on the agenda in recent years. Hydroxyapatite nanoparticles (HANP), which have a great similarity to bone tissue, stand out as a biocompatible nanoparticle. The different biodistribution properties of hydroxyapatite molecules in different nanosizes may create new opportunities for their use, especially in bone imaging and in the treatment of bone tumors. This study aims to investigate the labeling of hydroxyapatite molecules smaller than 50 nanometers obtained from eggshells with technetium-99m (^99mTc) and the in vivo distribution of this molecule in rabbits.

Materials and methods: Characterization of nanohydroxyapatite particles obtained from eggshells was performed using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). Radiolabeling of HANP smaller than 50nm with ^99mTc radionuclide, stability of the labeled product, and biodistribution profile in rabbits were investigated.

Results: The radiochemical purity of the ^99mTc-HANP was obtained as 96%. The in vitro stability of ^99mTc labeled HANP was examined for up to 12 hours and showed excellent in vitro stability for the first 4 hours in saline. Technetium-99m-HANP remained stable in vivo during the 6-hour imaging period. In quantitative analysis, ^99mTc-HANP showed accumulation in bone tissue in the second hour.

Conclusion: Technetium-99m-HANP nanoradiopharmaceuticals with sizes less than 50 nanometers (20-31nm) showed high uptake in bone tissue in rabbits. Therefore, HANP can be developed as imaging radiopharmaceuticals in bone tissue and bone cancers.

Objective: The clinical utility of quantitative fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for classification of medication-related osteonecrosis of the jaw (MRONJ) was determined.

Subjects and methods: Seventy-one lesions in 59 patients clinically diagnosed as MRONJ, based on American Association of Oral and Maxillofacial Surgeons (AAOMS) diagnostic criteria by Japanese Society of Oral Surgery specialists and who received ¹⁸F-FDG PET/CT examinations, were enrolled. For analysis, standard uptake values (SUV), including maximum (SUVmax), peak (SUVpeak), and mean (SUVmean) were evaluated, and also metabolic lesion volume (MLV) for total volume above the threshold, and total lesion glycolysis (TLG), calculated as MLVxSUVmean. To compare quantitative values between clinical stages, one-way repeated measures analysis of variance and subsequent post-hoc analysis were used.

Results: The mean SUVmax values for AAOMS stage 1 (n=13), 2 (n=43), and 3 (n=15) patients were 3.68±0.83, 6.15±1.32, and 9.92±1.63, respectively, while MLV values were 6.51±5.53, 8.76±9.74, and 13.92±13.89, respectively, and TLG values were 16.84±17.23, 31.36±35.25, and 66.27±58.51, respectively. Maximum SUV and TLG showed significant differences between clinical stages (P<0.0001 and P=0.0029, respectively). With stage increase, MLV showed a mild increasing tendency, though the difference between stages was not significant (P=0.13), while SUVmax value differences between individual stages were significant in subsequent post-hoc analysis (P<0.0001). Furthermore, post-hoc analysis indicated that the stage 3 TLG value was significantly greater than that of stage 1 and 2 (P<0.01 and P<0.05, respectively).

Conclusion: For MRONJ patients, SUVmax and TLG derived from quantitative ¹⁸F-FDG PET/CT results are reliable objective indicators useful for disease activity evaluation and staging.

General paresis (GP) is a type of neurosyphilis characterized by progressive memory impairment and mental disorders. It exhibits clinical, neuroimaging, and pathological similarities to Alzheimer's disease (AD). Here, we report a 37-year-old man with memory impairment and emotional disorders, who was clinically diagnosed with neurosyphilis, specifically GP. The fluorine-18 (¹⁸F)-Florbetapir positron emission tomography/computed tomography (PET/CT) of the patient showed mild diffuse amyloid deposition in both the cerebral and cerebellar cortex. Moreover, hypermetabolism in the left hippocampal region was revealed on ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT. The patient's cerebrospinal fluid (CSF) test and genotyping results further excluded coexistent genetic AD. This case highlights the significance of considering neurosyphilis as a possible differential diagnosis in dementia patients with atypical positive amyloid PET findings. The mechanisms underlying aberrant amyloid deposition in neurosyphilis require further investigation.

Objective: Chronic kidney disease (CKD) progression is accelerated by renal fibrosis, which causes abnormal extracellular matrix (ECM) accumulation. Non-invasive precision in measuring renal fibrosis is now possible with the help of advanced imaging techniques like magnetic resonance imaging (MRI) and ultrasound elastography. Fluorine-18-fibroblast activation protein (¹⁸F-FAP) is a promising Philips ingenuity TF positron emission tomography/computed tomography (PET/CT) scanner imaging target in activated fibroblasts associated with fibrotic disorders. Real-time quantification with FAP-targeted imaging improves kidney fibrosis diagnosis and guides anti-fibrotic therapies. The aim of this study is to develop reliable diagnostic and treatment techniques for renal fibrosis, Philips ingenuity TF PET/CT scanner imaging with FAP is useful.

Materials and methods: Positron emission tomography data from 100 patients in our hospital (October 2022-September 2023) was analyzed to see if renal radiotracer uptake correlated with CKD progression. Fluorine-18-FAPI-04 synthesis and Philips ingenuity TF PET/CT scanner imaging were standard. One person determined CKD stage and glomerular filtration rate (GFR) after imaging processing. Imaged renal radiotracer distribution using maximum standardized uptake value (SUVmax) and mean SUV (SUVmean). The study sought to improve renal radiotracer dispersion estimation for CKD assessment.

Results: The study reveals a complex relationship between GFR and radiotracer uptake in kidneys. At lower GFR, substantial uptake is seen, but a GFR of 15mL/min/1.73m² shows a drop to zero. Higher GFR generally correlate with increased uptake, peaking at GFR of 75 and 90mL/min/1.73m². Yet, at GFR of 115 and 120mL/min/1.73m², there is a reduction in radiotracer uptake, suggesting a nuanced association with renal function. Varied kidney SUVmax and SUVmean were significant for ¹⁸F-FAPI C (P<0.001), while baseline SUV readings were not significant. Fluorine-18-L-dihydroxyphenylalanine (¹⁸F-DOPA) and gallium-68 (⁶⁸Ga) ¹⁸F-prostate specific membrane antigen (PSMA) had significant kidney SUVmax values (P=0.05). Results suggest diverse absorption patterns for different radiotracers in kidneys and tissues.

Conclusion: Fluorine-18-FAPI is a promising noninvasive approach for evaluating and quantifying CKD grades. Its excellent CKD severity correlation and renal insights make it a transformative diagnostic tool.

Objective: To investigate the clinical utility of the 3D quantitative values derived from fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and bone single-photon computed tomography-computed tomography (SPECT/CT) for the diagnosis of osteoradionecrosis (ORN) of the jaw.

Subjects and methods: Thirty four patients with head and neck cancer who had a history of radiotherapy and clinically diagnosed as ORN and who undertaken ¹⁸F-FDG PET/CT (n=23) or quantitative bone SPECT/CT (n=11) were enrolled. Standardized uptake values (SUV), including maximum SUV (SUVmax), peak SUV (SUVpeak), and mean SUV (SUVmean), as well as metabolic lesion volume (MLV), representing total volume above threshold, and total lesion uptake (TLU), calculated as MLVxSUVmean were determined.

Results: In ¹⁸F-FDG PET/CT results, mean values (range) of SUVmax, SUVpeak, SUVmean, MLV, and TLU of 24 lesions were 6.72±2.62 (3.67~14.36), 5.25±2.05 (2.46~10.88), 3.77±1.33 (1.74~7.69), 11.49±9.61 (1.54~43.14), and 49.07±59.26 (4.44~271.05), respectively. In quantitative bone SPECT/CT results, mean values (range) of SUVmax, SUVpeak, SUVmean, MLV, and TLU of 16 lesions were 5.26±0.89 (3.71~7.07), 4.62±0.78 (3.09~6.02), 3.44±0.46 (2.68~4.32), 14.45±9.93 (1.48~33.32), and 49.72±35.51 (4.60~127.86), respectively.

Conclusion: As objective and reliable indicators, 3D quantitative values (SUV and volume) derived from ¹⁸F-FDG PET/CT and quantitative bone SPECT/CT results are useful for evaluation of the disease activity of ORN of the jaw.

Objective: This study aimed to explore the relationship between fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) uptake in the liver, spleen, and bone marrow and inflammatory markers such as c-reactive protein (CRP), albumin, and erythrocyte sedimentation rate (ESR) in patients undergoing positron emission tomography/computed tomography (PET/CT) imaging for cancer diagnosis.

Subjects and methods: This retrospective cross-sectional study included a total of 708 patients with a diagnosis of malignancy. Fluorine-18-FDG PET/CT images acquired between January 2021 and December 2022. Exclusion criteria comprised prior chemotherapy, radiotherapy, hematological malignancies, or liver/spleen tumors. Statistical analysis included correlation analysis, univariate, and multivariate regression analysis.

Results: C-reactive protein levels demonstrated a significant positive correlation with ¹⁸F-FDG uptake in the spleen (r=0.104, P=0.006) and bone marrow (r=0.112, P=0.003). Albumin showed a negative correlation with liver ¹⁸F-FDG uptake (r=-0.220, P<0.001). Regression analysis revealed ESR's impact on spleen-to-liver (P=0.023) and bone marrow-to-liver (P=0.012) ¹⁸F-FDG uptake.

Conclusion: This study demonstrates the association between inflammatory markers and ¹⁸F-FDG uptake in liver, spleen and bone marrow. C-reactive protein and ESR showing significant correlations with spleen and bone marrow ¹⁸F-FDG uptake, and albumin correlated with liver ¹⁸F-FDG uptake negatively. Erythrocyte sedimentation rate had significant impact on spleen and bone marrow ¹⁸F-FDG uptakes. These findings suggest the potential of ¹⁸F-FDG PET/CT in diagnosing inflammatory conditions, warranting further investigation into its clinical implications.

Positron emission tomography/computed tomography (PET/CT) is a hybrid medical imaging technique that combines PET and CT to provide detailed images of the body's anatomical structures and metabolic activity. It is frequently used for oncology and other medical diagnoses. This overview aims to examine how artificial intelligence (AI) has been used in PET/CT, based on recent state-of-art. There are a number of clinical questions in Nuclear Medicine, and AI could provide answers, having the capability to enhance various aspects of medical imaging. The overview focuses on how machine learning (ML) and deep learning (DL), enhance tumor segmentation, classification, diagnosis, disease-free survival prediction and treatment response prediction in oncology. The analysis showed that the application of AI provides reliable results, especially in the fields of classification and diagnosis. In addition, radiomics is a novel research field enabling quantitative analysis of medical images through feature extraction, utilized for AI model implementation. Despite these advances, addressing issues such as dataset size, standardization, and ethical concerns are essential for broad clinical integration of AI in PET/CT oncology imaging.