F-fluoro-2-deoxy-D-glucose Uptake Research Articles

Clinicopathologic parameters associated with the FDG-avidity in staging of early gastric cancer using 18F-FDG PET.

This study investigated the clinicopathologic factors associated with 2-[18F]fluoro-2-deoxy-d-glucose (18F-FDG) uptake of early gastric cancer (EGC) and used them to design a clinical scoring method to predict FDG-avidity of EGC.Two hundred twenty-nine retrospectively enrolled patients underwent preoperative 18F-FDG positron emission tomography/computed tomography (PET/CT). Histologic information was obtained by gastrectomy (n = 195) or endoscopic mucosal dissection (n = 34). The association between clinicopathologic factors and 18F-FDG uptake by the primary tumor was determined. The results were used to develop a clinical scoring method.18F-FDG uptake was detected in 49 (17.5%) patients. According to univariate analysis, location, gross type, World Health Organization classification, Lauren classification, size, depth of invasion, and lymphatic invasion were significant variables affecting 18F-FDG uptake (all P < .05). According to multivariate analysis, location (lower 3rd, P = .035), gross type (0–I, 0–IIa, P < .001), size (≥2.5 cm, P = .026), and depth of invasion (submucosa, P = .007) were significantly associated with FDG-avidity. A clinical scoring system, ranged from 0 to 4, was developed by giving one score to 4 independent variables. A cut-off value of 2.5 showed good prediction of FDG-avidity in EGCs, with a sensitivity and specificity of 65.0% and 85.2%, respectively.18F-FDG uptake by EGC depends on location, gross type, size, and depth of invasion of the primary tumor. A clinical scoring system based on clinicopathologic variables can predict the FDG-avidity of primary tumors in patients with EGC.

Diffusely increased bone marrow FDG uptake in recently untreated lymphoma: incidence and relevance

To determine the incidence of diffusely increased bone marrow (18) F-fluoro-2-deoxy-D-glucose (FDG) uptake at positron emission tomography (PET) in recently untreated lymphoma and to assess the frequency of lymphoma-positive bone marrow biopsies (BMBs) in these patients. FDG-PET scans of all patients presenting with newly diagnosed or relapsed lymphoma were reviewed. Patients with non-focal diffusely increased bone marrow FDG uptake, who had not received therapy within 3months, were identified. The incidences of diffusely increased bone marrow FDG uptake and the frequencies of positive posterior iliac crest BMBs among those cases were calculated. The incidences of diffusely increased bone marrow FDG uptake in all lymphomas, and in Hodgkin lymphoma, aggressive non-Hodgkin lymphoma (NHL), indolent NHL, and mantle cell NHL separately, were 4.2% (23/542), 9.3% (7/75), 3.4% (8/239), 3.3% (7/214), and 7.1% (1/14), respectively, and frequencies of positive BMBs among these subgroups were 55.0% (11/20), 0.0% (0/7), 83.3% (5/6), 83.3% (5/6), and 100% (1/1), respectively. The incidence of diffusely increased bone marrow FDG uptake in recently untreated lymphoma is low, albeit higher in Hodgkin lymphoma than in NHL. BMB in such patients is likely to be negative in Hodgkin lymphoma, but positive in the majority of NHL cases.

Differential human brain activity induced by two perceptually indistinguishable gentle cutaneous stimuli

We examined differences in brain activity in response to two types of mechanical stimulation, which have been reported previously as being perceptually indistinguishable but having different impacts on autonomic reflexes. As an indicator of brain activity, glucose metabolism was evaluated by PET with 2-[F]fluoro-2-deoxy-D-glucose (F-FDG). Twelve healthy, young adult men participated in the study. Two types of cutaneous stimulation tools, soft elastomer discs with microcones (microcone disc) or flat surfaces (flat disc), were used in a crossover, randomized double-blind manner. Each type of cutaneous stimulation tool was applied on the cheeks and F-FDG-PET scans were obtained. Greater F-FDG uptake was observed in the right anterior cingulate cortex during microcone disc stimulation compared with flat disc stimulation. However, F-FDG uptake during application of these two different stimuli was not different in the primary and secondary somatosensory cortices or insula. Stimulation using microcone discs and flat discs was noted by one and three participants, respectively, and there was no difference in the presence of perception between the stimulation tools. The results indicate that the right anterior cingulate cortex differentially responds to different types of cutaneous stimulation that are perceptually indistinguishable.

Thyroid Incidentalomas on FDG PET/CT in Patients with Non-Thyroid Cancer - a Large Retrospective Monocentric Study

Background: The purpose of this study was to compare the incidence of thyroid cancer among patients with primary non-thyroid cancer, who showed focal thyroid uptake in ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT). Material and Methods: We reviewed a total of 22,674 FDG PET/CTs performed at our institution between March 2005 and June 2011. A retrospective review was conducted on 433 non-thyroid cancer patients (male: n = 90, female: n = 343) who had thyroid incidentaloma on FDG PET/CT. In 286 patients, diagnostic confirmation was done by ultrasound-guided fine needle aspiration biopsy (FNAB). Results: Among 22,674 FDG PET/CT scans, 483 subjects (2.1%) showed focal thyroid uptake. Among the 286 patients who underwent FNAB, 280 were included in the study. Of those, 68 patients (24.3%) demonstrated papillary thyroid carcinoma on the final pathologic findings. We divided patients into 7 groups depending on the primary cancer. Conclusion: In patients with cancer of non-thyroid origin, incidental FDG uptake in the thyroid gland was observed in 2.1% and associated with a 24.3% risk for well-differentiated thyroid carcinoma. However, there was no statistically significant difference in the malignant risk of focal FDG uptake of the thyroid gland according to the underlying primary non-thyroid cancer type.

FDG Uptake of Normal Canine Brain Assessed by High-Resolution Research Tomography-Positron Emission Tomography and 7 T-Magnetic Resonance Imaging

The purpose of this study was to assess the normal distribution of (18)F-fluoro-2-deoxy-D-glucose (FDG) uptake of canine brain structures using a high-resolution research tomography-positron emission tomography (HRRT-PET) and 7 T-magnetic resonance imaging (MRI) fusion system. FDG-PET and T2-weighted MRI of the brain were performed on 4 healthy laboratory beagle dogs. On MRI, regions of interests (ROIs) were manually drawn over 51 intracranial structures, including nine gross structures and 42 detailed structures. Relative standard uptake value ratio (rSUV=SUV of ROI/SUV of whole brain) was calculated for each ROI. The HRRT-PET and 7 T-MRI fusion imaging system demonstrated significant differences in glucose metabolism among various intracranial structures. Among gross structures, the midbrain and the pons and medulla oblongata had the highest uptake (rSUV: 1.12 ± 0.03) and lowest uptake (rSUV: 0.90 ± 0.06) of FDG, respectively. When rSUVs were calculated on detailed regions, the caudal colliculus and the longitudinal fibers of pons had the highest (rSUV: 1.62 ± 0.05) and the lowest (rSUV: 0.63 ± 0.03) glucose metabolism, respectively. Because the high resolution of PET-MRI fusion images provided clearly identifiable metabolic activities of canine brain, the HRRT-PET and 7 T-MRI fusion imaging might be a good tool for evaluation of intracranial diseases in canines.

Viability and proliferation potential of adipose-derived stem cells following labeling with a positron-emitting radiotracer

Adipose-derived stem cells (ASCs) have promising potential in regenerative medicine and cell therapy. Our objective is to examine the biological function of the labeled stem cells following labeling with a readily available positron emission tomography (PET) tracer, (18)F-fluoro-2-deoxy-D: -glucose (FDG). In this work we characterize labeling efficiency through assessment of FDG uptake and retention by the ASCs and the effect of FDG on cell viability, proliferation, transdifferentiation, and cell function in vitro using rat ASCs. Samples of 10(5) ASCs (from visceral fat tissue) were labeled with concentrations of FDG (1-55 Bq/cell) in 0.75 ml culture medium. Label uptake and retention, as a function of labeling time, FDG concentration, and efflux period were measured to determine optimum cell labeling conditions. Cell viability, proliferation, DNA structure damage, cell differentiation, and other cell functions were examined. Non-labeled ASC samples were used as a control for all experimental groups. Labeled ASCs were injected via tail vein in several healthy rats and initial cell biodistribution was assessed. Our results showed that FDG uptake and retention by the stem cells did not depend on FDG concentration but on labeling and efflux periods and glucose content of the labeling and efflux media. Cell viability, transdifferentiation, and cell function were not greatly affected. DNA damage due to FDG radioactivity was acute, but reversible; cells managed to repair the damage and continue with cell cycles. Over all, FDG (up to 25 Bq/cell) did not impose severe cytotoxicity in rat ASCs. Initial biodistribution of the FDG-labeled ASCs was 80% + retention in the lungs. In the delayed whole-body images (2-3 h postinjection) there was some activity distribution resembling typical FDG uptake patterns. For in vivo cell tracking studies with PET tracers, the parameter of interest is the amount of radiotracer that is present in the cells being labeled and consequent biological effects. From our study we developed a labeling protocol for labeling ASCs with a readily available PET tracer, FDG. Our results indicate that ASCs can be safely labeled with FDG concentration up to 25 Bq/cell, without compromising their biological function. A labeling period of 90 min in glucose-free medium and efflux of 60 min in complete media resulted in optimum label retention, i.e., 60% + by the stem cells. The initial biodistribution of the implanted FDG-labeled stem cells can be monitored using microPET imaging.

A new dimension of FDG-PET interpretation: assessment of tumor biology

(18)F-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) is increasingly being used for the evaluation of several malignancies. Key to the correct interpretation of oncological FDG-PET studies is awareness of the concept that the degree of FDG uptake reflects the biology of the tumor in many cancers. More specifically, cancers with high FDG uptake are often histologically and clinically more aggressive than those with low or no FDG uptake. Therefore, although a negative FDG-PET scan in a patient with a cancer that has a size above the spatial resolution of PET may be interpreted as false-negative in terms of tumor detectability, it should in fact be regarded as true-negative from the view-point of tumor biology. This nonsystematic review will give examples of several major cancers in which the relationship between FDG avidity and tumor biology is applicable, and emphasizes the need to reconsider the definition of a "false-negative" FDG-PET scan in clinical oncology.

18F-FDG-PET-CT imaging findings of recurrent intracranial haemangiopericytoma with distant metastases

A 42-year-old woman presented with local recurrence and distant lung and liver metastases 7 years after resection of a primary intracranial haemangiopericytoma. Whole-body (18)F-fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET)-CT scan showed no increased uptake in local recurrence or distant metastases except for a focus of increased FDG uptake within a hepatic metastasis. The hypermetabolic area correlated with an intratumoral hypoenhancing area on the CT scan. PET-CT scan may be useful to allow further understanding of the tumour.

Riluzole protects Huntington disease patients from brain glucose hypometabolism and grey matter volume loss and increases production of neurotrophins

Huntington disease (HD) mutation increases gain-of-toxic functions contributing to glutamate-mediated excitotoxicity. Riluzole interferes with glutamatergic neurotransmission, thereby reducing excitotoxicity, enhancing neurite formation in damaged motoneurons and increasing serum concentrations of BDNF, a brain cortex neurotrophin protecting striatal neurons from degeneration. We investigated metabolic and volumetric differences in distinct brain areas between 11 riluzole-treated and 12 placebo-treated patients by MRI and (18)F-fluoro-2-deoxy-D-glucose (FDG) PET scanning, according to fully automated protocols. We also investigated the influence of riluzole on peripheral growth factor blood levels. Placebo-treated patients showed significantly greater proportional volume loss of grey matter and decrease in metabolic FDG uptake than patients treated with riluzole in all cortical areas (p<0.05). The decreased rate of metabolic FDG uptake correlated with worsening clinical scores in placebo-treated patients, compared to those who were treated with riluzole. The progressive decrease in metabolic FDG uptake observed in the frontal, parietal and occipital cortex correlated linearly with the severity of motor scores calculated by Unified Huntington Disease Rating Scale (UHDRS-I) in placebo-treated patients. Similarly, the rate of metabolic changes in the frontal and temporal areas of the brain cortex correlated linearly with worsening behavioural scores calculated by UHDRS-III in the placebo-treated patients. Finally, BDNF and transforming growth factor beta-1 serum levels were significantly higher in patients treated with riluzole. The linear correlation between decreased metabolic FDG uptake and worsening clinical scores in the placebo-treated patients suggests that FDG-PET may be a valuable procedure to assess brain markers of HD.

Laparoscopic scar: A mimicker of Sister Mary Joseph’s nodule on positron emission tomography/CT

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. (18)F-fluoro-2-deoxy-d-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT.

PET and PET/CT using 18F-FDG in the diagnosis and management of cancer patients

Positron emission tomography (PET) using 2-(18)F-fluoro-2-deoxy-D-glucose (FDG), a radioactive derivative of glucose, is an advanced imaging tool, based on the increased glucose consumption of cancer cells. FDG-PET provides information that is not obtainable with other imaging modalities, and is very effective in the diagnosis and management of patients with various types of cancers. However, there are some limitations, such as low FDG uptake in some cancers, substantial FDG uptake in inflammatory cells, and the lack of anatomical information and poor imaging quality of PET. A recently developed integrated PET/computed tomography (CT) system, which combines a PET camera and CT scanner in a single session, has overcome these drawbacks by providing both anatomical and functional imaging at the same position. PET and/or PET/CT using FDG is clinically useful in the detection of cancer, the differentiation of malignant and benign lesions, the staging of cancer before therapy, and the assessment of cancer therapy, as well as for determining the recurrence after therapy of most cancers, including lung cancer, gastrointestinal cancer, breast cancer, and malignant lymphoma. PET/CT has become the new standard approach to imaging in the diagnosis and management of many cancer patients.

PET imaging of brain astrocytoma with 1-11C-acetate

The purpose of this study was to assess the use of 1-(11)C-acetate (ACE) as a metabolic tracer for the detection and characterisation of astrocytomas. Positron emission tomography (PET) studies with ACE and 2-(18)F-fluoro-2-deoxy-D-glucose (FDG) were performed sequentially in 26 patients with primary astrocytomas. Images were analysed by visual interpretation and determination of the tumour to cortex ratio (T/C ratio) and standardised uptake value (SUV). The tumour uptake was visually scored into three grades as compared with the contralateral cortex: clearly lower (-), almost equal (+) and clearly higher (++). There were 85% of astrocytomas with ++ ACE uptake, 15% with + ACE uptake and none with - ACE uptake. Only 19% of astrocytomas had ++ FDG uptake. Thirty-seven percent of high-grade astrocytomas had + FDG uptake and 37% had - FDG uptake. The sensitivity and specificity of the FDG T/C ratio in discriminating high-grade from low-grade astrocytomas were 79% and 100%, respectively, at the cutoff value of 0.75. Using 2.33 as the cutoff value of the ACE T/C ratio, the sensitivity and specificity were 42% and 86%, respectively. FDG was better than ACE in discriminating high-grade from low-grade astrocytomas. T/C ratios and SUVs of FDG uptake of tumours correlated with the histological grades, but those of ACE uptake did not. ACE appears to be a promising tracer for use in the detection of primary astrocytomas, but is of limited value in the differentiation of high- and low-grade astrocytomas. ACE is complementary to FDG for the diagnosis and characterisation of astrocytoma.

Differential Regional Cerebral Uptake of 18F-Fluoro-2-Deoxy-D-Glucose in Alzheimer’s Disease and Frontotemporal Dementia at Initial Diagnosis

In this paper, the cerebral uptake of ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) was studied in a relatively small group of patients suffering from either clinically diagnosed Alzheimer’s disease (AD) or frontotemporal dementia during the initial differential diagnostic workup. The image analysis was done visually and semiquantitatively using three different reference regions. Visual analysis confirmed earlier literature findings on the distribution of decreased FDG uptake and demonstrated prevalent asymmetric patterns in both groups. Only semiquantitative analysis using the sensorimotor cortex as a reference region confirmed the visual findings. Moreover, there were no differences in medial temporal lobe activities between both groups, and there was no correlation of medial temporal lobe activity with dementia severity. In the AD group, a correlation of parietal FDG uptake with MMSE scores was found.