FDG-PET Findings Research Articles

Clinicopathological Features of Ductal Carcinoma In Situ from 18F-FDG-PET Findings.

The presence of ductal carcinoma in situ (DCIS) can increase the risk of developing an invasive ductal carcinoma (IDC), but it is difficult to predict what will occur if a DCIS is left untreated. We reported the usefulness of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for DCIS, and that the presence of FDG uptake in the tumor could be considered a predictor of invasive potential in patients with DCIS. In this study, we retrospectively evaluated the clinicopathological features of DCIS by using FDG-PET findings, and we evaluated the possibility of using FDG-PET in DCIS cases as a biomarker of which lesions will go on to become invasive. We investigated the cases of 185 consecutive patients with primary breast cancer who were diagnosed as having DCIS or IDC and underwent FDG-PET preoperatively. We divided the cases into two groups on the basis of histology; DCIS vs. IDC (n=171). The DCIS cases were divided into two groups on the basis of FDG uptake in the primary tumor. Fourteen of the 185 patients (7.4%) were revealed to have a DCIS. The analysis revealed that the SUVmax and the number of cases not detected by FDG-PET were significantly different between the DICS and IDC groups. The extent of the primary tumor was not significantly different between the two groups. In six cases (42.9%) of the 14 DCIS cases, no FDG uptake was detected by FDG-PET. The extent of tumor did not significantly differ between the two groups. In addition, all six cases without FDG uptake were of the diffuse-spread type, without mass formation. All eight cases with mass formation had FDG uptake. Our present findings suggest that the FDG-PET uptake reflects tumor burden or tumor density, which should be considered to be associated with the presence of invasion.

Emerging clinical issues and multivariate analyses in PET investigations.

PET using 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET) has been gradually introduced in the diagnostic clinical criteria of the most prevalent neurodegenerative diseases. Moreover, an increasing amount of literature has shown that the information provided by FDG-PET enhances the sensitivity of standard imaging biomarkers in less frequent disorders in which an early differential diagnosis can be of paramount relevance for patient management and outcome. Therefore emerging uses of FDG-PET may be important in prion diseases, autoimmune encephalitis (AE) and amyotrophic lateral sclerosis. Interestingly, FDG-PET findings can also be observed in the early phases of these conditions, even in the presence of normal magnetic resonance imaging scans. Thalamic hypometabolism is a common finding in sporadic Creutzfeldt-Jacob disease and fatal familiar insomnia patients, with further cortical synaptic dysfunction in the former. Limbic and extra-limbic metabolic abnormalities (more often hypermetabolism) can be observed in AE, although specific patterns may be seen within different syndromes associated with antibodies that target neuronal surface or synaptic antigens. FDG-PET shows its usefulness by discriminating patients with amyotrophic lateral sclerosis associated to upper motor neuron onset that evolve to frontotemporal dementia. Besides visual and voxel based image analysis, multivariate analysis as interregional correlation analysis and independent/principal component analysis have been successfully implemented to PET images increasing the accuracy of the discrimination of neurodegenerative diseases. The clinical presentation and current diagnostic criteria of these neurologic disorders as well as the emerging usefulness of FDG-PET in the diagnostic workup are presented and discussed in this review.

Sequential FDG PET and MRI findings in a case of SMART syndrome

Sequential FDG PET and MRI findings in a case of SMART syndrome

Everyday cognition scales are related to cognitive function in the early stage of probable Alzheimer\u2019s disease and FDG-PET findings

We applied the Everyday Cognition (ECog) scale in normal aging adults and patients with Alzheimer’s disease (AD) to investigate associations between neuropsychological tests and neuroimaging markers. A total of 160 normal aging adults and 40 patients with the early stage of probable AD were included. Neuropsychological performance was assessed using the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Assessment Battery (CERAD-NAB). 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans were used to measure AD-related hypometabolism. Nonparametric Spearman correlation analysis was used to study associations between ECog and z-transformed total CERAD-NAB scores in both groups. The results revealed a significant correlation between total ECog and CERAD-NAB scores (rho = −0.28, p < 0.01), and category verbal fluency test with the executive domain of the ECog scale (rho = −0.20, p < 0.01). The CERAD-NAB scores were also significantly correlated with AD-related hypometabolism (rho = −0.49, p < 0.01). The memory domain of the ECog scale was significantly correlated with FDG uptake in the angular gyrus and posterior cingulum gyrus (rho = −0.41 and −0.46, P < 0.01). In conclusion, both total and memory domain ECog scores were correlated with the neuropsychological tests and neuroimaging biomarkers.

Cerebral FDG-PET Findings in Patients with Traumatic Disorders of Consciousness: Preliminary Results of a Pilot Study (P5.159)

Cerebral FDG-PET Findings in Patients with Traumatic Disorders of Consciousness: Preliminary Results of a Pilot Study (P5.159)

The utility of FDG-PET in the differential diagnosis of Parkinsonism

Introduction: Differential diagnosis of parkinsonian disorders can be difficult on clinical grounds, especially in the early stage. Recent advancements in 18-F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging reveals different patterns of regional glucose metabolism in idiopathic Parkinson’s disease (IPD) and atypical parkinsonian syndromes, such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), which may help differentiating between these conditions.Purpose: To assess the utility of FDG-PET imaging in differential diagnosis of Parkinsonism in clinical practice.Methods: FDG-PET was performed in 72 patients with parkinsonism (age 34–80 years) referred to our center by movement disorder specialists. FDG-PET diagnosis was obtained by visual assessment of individual scans combined with voxel-based statistical parametric mapping analysis. FDG-PET diagnosis assigned at the time of imaging was compared with the final clinical diagnosis made by the movement disorder specialists after ≥2 years follow-up.Results: FDG-PET findings were consistent with IPD in 27, MSA in 18, PSP in 19 and CBS in 2 patients. The final clinical diagnosis was IPD in 29, MSA in 20, PSP in 21 and CBS in 2 patients. Concordance between the FDG-PET and clinical diagnoses was 92% in the overall sample (IPD 93%, MSA 90%, PSP 91% and CBS 100%). The diagnostic accuracy of FDG-PET was 93% for IPD and MSA and 97% for PSP.Conclusion: FDG-PET may help differentiate between IPD, MSA, PSP and CBS among patients presenting with parkinsonian symptoms, which is important for patient counselling and making early decisions about treatment.

FDG-PET predicts treatment efficacy and surgical outcome of pre-operative chemoradiation therapy for resectable and borderline resectable pancreatic cancer

BackgroundThe efficacy of neoadjuvant chemoradiotherapy (NACRT) for resectable and borderline resectable pancreatic cancer is important for predicting outcomes after radical surgery, but few clinical indicators predict outcome before resection. This study examined the utility of FDG-PET in predicting the efficacy of NACRT and outcome after radical surgery. MethodsEighty-three pancreatic cancer patients who underwent FDG-PET before and after NACRT and had positive standard uptake values (SUVs) before NACRT were enrolled in this study. Peri-operative clinical factors, including FDG-PET findings, were examined to predict the efficacy of NACRT and outcome after surgery. ResultsEvans grade I, IIA, IIB, III, and IV was determined in 11, 31, 27, 11, and 3 patients, respectively. The maximum SUVs after NACRT (post SUV-max) and tumor size were significantly decreased compared to pretreatment values (p < 0.001 and p = 0.007, respectively). The post SUV-max and regression index were significantly related to grade III/IV (p = 0.04 and p < 0.001, respectively), but only the regression index predicted NACRT efficacy (p = 0.002). The AUC of the regression index for the detection of grade III/IV was 0.822, and 13 of 14 grade III/IV patients were picked up using 50% as the threshold (p < 0.001). Patients with a regression index >50% had a significantly better prognosis after radical resection than patients with <50% (p = 0.032). Regression index as well as pathological lymph node status and resectability status were independent prognostic factors in multivariate analysis (exp 2.086, p = 0.043). ConclusionThe regression index is potentially a good indicator of the efficacy of NACRT and outcome after radical resection for pancreatic cancer.

Incremental Prognostic Value of Global Longitudinal Strain and 18F-Fludeoxyglucose Positron Emission Tomography in Patients With Systemic Sarcoidosis

In independent studies, abnormal global longitudinal strain (GLS) and myocardial inflammation or scar detected by 18F-fludeoxyglucose positron emission tomography (FDG-PET) are associated with poor prognosis among patients with high likelihood for cardiac sarcoidosis. However, commonly used imaging modalities have not been evaluated in the same population. Our goals were to examine the relation between GLS and FDG-PET, and to evaluate the incremental prognostic value of these imaging techniques for predicting major adverse cardiac events (MACE) in patients suspected to have cardiac sarcoidosis. We identified patients with systemic sarcoidosis who underwent an echocardiogram and FDG-PET within 60days. Regional strain (average of base, mid, and apical segmental strains from each of 6 wall regions) was calculated and compared with regional FDG-PET findings. The associations among GLS, FDG-PET findings, and MACE (defined as death, ventricular tachycardia, heart failure hospitalization, or transplantation) were evaluated using a Cox model. Of 84 patients, 51 had abnormal FDG-PET. GLS was impaired in patients with abnormal versus normal FDG-PET (-14.2 ± 4.7% vs-17.9 ± 3.5%, p <0.01). After adjusting for clinical risk factors, both GLS and the number of segments with abnormal perfusion and metabolism on FDG-PET were associated with adverse cardiac events (p <0.01 for both). In conclusion, GLS and regional LS are impaired in patients with abnormal perfusion and metabolism detected using FDG-PET. Additionally, both GLS and abnormal FDG-PET have incremental prognostic value for predicting MACE in patients with systemic sarcoidosis.

A Practical Guide to Interpreting FDG PET and CT Nodal Findings in Lung Cancer

FDG PET/CT has been used to help characterize indeterminate pulmonary nodules, and to stage Non-Small Cell Lung Cancer (NSCLC) since January of 1998. The ever-expanding utilization of this modality in oncologic imaging cancer patients presented unique challenges for imagers who may not have received specialized training in the interpretation of PET/CT images. Interpretation of FDG PET/CT is particularly challenging in the thorax where inflammatory processes are common and often coexist with malignancy, rendering accurate tumor staging difficult. This article presents a systematic approach to FDG PET/CT interpretation in lung cancer staging, addressing common confounding situations often encountered. Although this illustrative discussion focuses on lung cancer staging, most of these tips could be applied to other types of cancer as well.

Unusual FDG-PET Findings in Traumatic Brain Injury; Did Traumatic Brain Injury Provoke Rapid Progression of Alzheimer's Disease?

Traumatic brain injury (TBI) is common, and is often the leading cause of disability and death. Complications after TBI include increased risk for chronic central nervous system disease, such as Alzheimer's disease (AD). However, the pathophysiology relating acute injury to neurodegeneration is unclear. Here we present a case of a patient whose cognition declined after TBI, and whose 18F fluorodeoxyglucose positron emission tomography scan showed an AD pattern.

OA18.05 FDG-PET in Thymic Epithelial Tumors: An Evaluation of Only Resected Tumors

18F-Fluorodeoxy glucose positron emission tomography (FDG- PET) is thought to be useful for predicting the histologic grade in thymic epithelial tumors (TETs). Although there have been many reports on the use of FDG-PET for evaluating TETs, no previous studies have included only resected cases. Therefore, we investigated the relationship between the degree of FDG-uptake in the tumor and either the WHO histologic subtype or the tumor stage in patients with resected TETs. We retrospectively reviewed FDG-PET findings in 112 patients with TETs (92 with thymomas and 20 with thymic carcinomas) resected at 2 institutes in Japan. The Spearman rank correlation coefficient was used to assess the association between the maximum standardized uptake value (SUV max) in the tumor and both the histologic subtype and tumor stage. The cut-off value of SUV max for differentiating thymoma from thymic carcinoma was calculated using a receiver operating characteristic (ROC) curve analysis. The Table shows the relationship between SUV max in the tumor and the WHO histologic subtype. SUV max according to each tumor stage was 3.9 ± 1.7 (mean ± SD) in stage I (n = 89), 4.7 ± 1.7 in stage II (n = 3), 7.4 ± 5.3 in stage III (n =11), and 7.6 ± 3.9 in stage IV (n = 9). SUV max was strongly related to both the WHO histologic subtype and tumor stage (Spearman rank correlation coefficient = 0.485 and 0.432; p = 0.000 and 0.000, respectively). The optimal cut-off value of SUV max for differentiating thymoma from thymic carcinoma was 4.6, with a sensitivity of 80% and a specificity of 70%.Tabled 1Histologic subtypeNo. of patientsSUV maxRangeMean ± SDA123.5 ± 1.31.3 – 6.3AB453.5 ± 1.31.2 – 6.9B1194.1 ± 0.92.5 – 6.5B2104.2 ± 1.02.7 – 5.9B364.8 ± 2.62.4 – 8.6Thymic carcinoma208.0 ± 4.73.0 – 21.8Total1124.5 ± 2.81.2 – 21.8 Open table in a new tab Our results suggest that FDG-PET is useful for differentiating thymoma from thymic carcinoma. Further studies will be needed to assess other potential clinical applications of FDG-PET for the evaluation of TETs.

Abstract 11929: Simultaneous Assessment of Myocardial Viability With 18 F-fluorodeoxyglucose Uptake and Late Gadolinium Enhancement by PET/MRI

Introduction: Both 18 F-fluorodeoxyglucose (FDG) PET and late gadolinium enhancement on cardiac MRI (LGE-CMR) have been utilized for myocardial viability evaluation. However, the association between these 2 modalities has not been fully investigated. The aim of this study was to compare FDG PET and LGE-MRI findings simultaneously using an integrated PET/MRI. Methods: Twelve participants (age 68.8 ± 7.9 years old, 11 males, left ventricular ejection fraction 40.5 ± 15.0%) with old myocardial infarction were enrolled. Total 204 segments were analyzed according to the 17-segment model. FDG PET/MRI was performed for each participant under hyperinsulinaemic-euglycemic state. The FDG uptake was semiquantitatively measured as %uptake. The transmural extent of LGE-CMR was evaluated by a 5-point scoring system (0 = 0%, 1 = 1-25%, 2 = 26-50%, 3 = 51-75%, 4 = 76-100%). Left ventricular (LV) wall thickness at end-diastolic phase and LV wall thickening were also measured by CMR. Viable myocardium was defined as less than 50% of the transmural extent of LGE-CMR. Results: Relative FDG uptake and the transmural extent of LGE-CMR were significantly correlated (P &lt; 0.0001, Spearman ρ = -0.63). Relative FDG uptake was correlated with LV wall thickness (P = 0.003, ρ = 0.22) and LV wall thickening (P &lt; 0.0001, ρ = 0.59). Receiver operating characteristic analysis demonstrated that the best cut-off value of FDG uptake to predict myocardial viability was 63% (area under the curve 0.90). When the cut-off value set to 63%, sensitivity was 81.6%, specificity was 80.8%, and accuracy was 81.4%. Conclusions: Relative FDG uptake was comparable to the transmural extent of LGE-CMR in assessing myocardial viability. Simultaneous evaluation using the integrated PET/MRI is feasible and may provide novel insights into evaluation of the myocardial viability.

Serial 18F-FDG PET/CT Findings in a Patient With IgLON5 Encephalopathy

We presented the serial FDG PET/CT brain scans of a 64-year-old woman with IgLON5 encephalopathy, which is a novel syndrome in association with antibodies to a neuronal cell adhesion protein named IgLON5, and FDG PET findings have not been characterized previously. For our case, the relatively hypermetabolism in primary sensorimotor cortices, basal ganglia, and cerebrum comparing to other cortical regions on the pretreatment FDG PET/CT was partially recovered on the follow-up FDG PET/CT scan after immunotherapy, corresponding with the alleviation of clinical syndromes. The metabolic change pattern was not similar as other types of autoimmune encephalitis.

Cerebral FDG-PET Findings in Patients with Traumatic Disorders of Consciousness: Preliminary Results of a Pilot Study

Cerebral FDG-PET Findings in Patients with Traumatic Disorders of Consciousness: Preliminary Results of a Pilot Study

Controversies on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma.

Hodgkin lymphoma, even in advanced-stage, is a highly curable malignancy, but treatment is associated with short-term toxicity and long-term side effects. Early predictive markers are required to identify those patients who do not require the full-length standard therapy (and thus qualify for therapy de-escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of 18 F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) after a few cycles of chemotherapy (also known as 'interim FDG-PET') in predicting outcome in advanced-stage Hodgkin lymphoma. Furthermore, multiple interim FDG-PET-adapted trials, in which patients with positive interim FDG-PET scans are assigned to escalated therapies, and patients with negative interim FDG-PET scans are assigned to de-escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma in patients with positive and negative interim FDG-PET findings following continuation of standard chemotherapy or escalated/de-escalated therapy.

Differences in Brain Metabolic Impairment between Chronic Mild/Moderate TBI Patients with and without Visible Brain Lesions Based on MRI.

Introduction. Many patients with mild/moderate traumatic brain injury (m/mTBI) in the chronic stage suffer from executive brain function impairment. Analyzing brain metabolism is important for elucidating the pathological mechanisms associated with their symptoms. This study aimed to determine the differences in brain glucose metabolism between m/mTBI patients with and without visible traumatic brain lesions based on MRI. Methods. Ninety patients with chronic m/mTBI due to traffic accidents were enrolled and divided into two groups based on their MRI findings. Group A comprised 50 patients with visible lesions. Group B comprised 40 patients without visible lesions. Patients underwent FDG-PET scans following cognitive tests. FDG-PET images were analyzed using voxel-by-voxel univariate statistical tests. Results. There were no significant differences in the cognitive tests between Group A and Group B. Based on FDG-PET findings, brain metabolism significantly decreased in the orbital gyrus, cingulate gyrus, and medial thalamus but increased in the parietal and occipital convexity in Group A compared with that in the control. Compared with the control, patients in Group B exhibited no significant changes. Conclusions. These results suggest that different pathological mechanisms may underlie cognitive impairment in m/mTBI patients with and without organic brain damage.

Clinical Impact of a Second FDG-PET in Atypical/Unclear Dementia Syndromes.

Diagnosis of atypical/unclear dementia is often difficult and this delays treatment initiation. Several authors have shown that beyond standard dementia workup, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) reduces the number of unclear diagnoses, leads to earlier treatment, and has a beneficial impact on families. However, it is not uncommon that the FDG-PET findings are equivocal in this setting. For those cases, a repeat FDG-PET may clarify the diagnosis and prevent treatment delay. We retrospectively assessed the clinical impact of a repeat FDG-PET in 59 patients with atypical/unclear dementia syndromes and inconclusive initial FDG-PET. Changes in primary diagnosis, diagnostic confidence, and management following the second FDG-PET were examined. Conducting a second FDG-PET reduced the number of unclear diagnoses from 80% to 34% , led to diagnostic change in 24% of cases, and treatment modification in 22% of patients. Overall, the clinical impact was higher when initial diagnostic confidence was low and the second FDG-PET repeated ≥12 months after the first one. In tertiary care memory clinic settings, when diagnostic incertitude persists despite extensive evaluation and an equivocal FDG-PET, repeating the FDG-PET 12 months later can greatly clarify the diagnosis and improve management.

RARE-17NEUROENDOCRINE CARCINOMA IN THE BRAIN

OBJECT: Neuroendocrine carcinoma (NEC) is a malignant tumor that usually arises in the lung, pancreas and gastrointestinal tract. Brain metastasis of NEC is merely reported. Herein, we report two cases of NEC in the brain mimicking glioblastoma (GBM). CASES: Both patients were in their 60s, cystic lesions with peritumoral edema affected the temporal lobe. Cyst walls were thin but hyperintense in diffusion weighted images implying increased cellularity. Positron emission tomography (PET) revealed malignant nature by strong uptake of methionine (MET), fluorothymidine (FLT) and fluoromisonidazole likewise GBM. However, fluorodeoxyglucose (FDG) indicated relatively weak uptakes compared as GBM. Both tumors were resected under the preoperative diagnosis of GBM, however, pathological diagnoses were NEC by immunohistochemical finding of negative GFAP and positive markers of neuroendocrine differentiation. Systemic examination failed to reveal the origin. Both cases underwent radiotherapy. One case was lost by spinal dissemination 11 months after the operation. DISCUSSION: FDG-PET of neuroendocrine tumor in the extracranial lesion does not always demonstrate strong uptake. FDG-PET for NEC in the brain could be less accumulated than GBM, while it should be evaluated keeping in mind that the background level of FDG would be high in the brain tissue. In case of malignant tumors endorsed by other tracer such as MET and FLT, inconsistent FDG-PET finding might be useful for the diagnosis of NEC in the brain.

Sensory processing abnormalities in children with severe autism – Do they correlate with FDG-PET findings?

Sensory processing abnormalities in children with severe autism – Do they correlate with FDG-PET findings?

Characteristics of FDG-PET findings in the diagnosis of systemic juvenile idiopathic arthritis

Objective: To examine and delineate inflammatory focus in patients with juvenile idiopathic arthritis (JIA), 18F-Fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) (18F-FDG-PET) was applied to patients with JIA, and the images of these patients were compared.Methods: Sixty-eight children (59 with systemic JIA (s-JIA) and 9 with polyarticular JIA) were included. The diagnosis of JIA was done to meet the International League of Associations for Rheumatology (ILAR) criteria. After 6-h fasting, whole-body positron emission tomography (PET) scans were acquired 60 min after intravenous injection of 3–5 MBq/kg 18F-FDG. The interpretation of 18F-FDG uptake was based on visual characteristics.Results: Two types of PET images were outstanding in s-JIA; one was 18F-FDG uptake in red bone marrow, such as the spine, pelvis, and long bones as well as spleen (12 cases), and other type was the uptake in the major joints, such as hips, elbows, wrists, knees, and ankles (8 cases). The former findings were correlated with elevated levels of inflammatory markers, while the latter were with significantly increased levels of MMP-3 (p < 0.05).Conclusion: There was a noticeable accumulation of 18F-FDG uptake in bone marrow of s-JIA patients which may indicate the inflammatory focus of this disease and play an important role in the pathogenic basis of arthritis and systemic inflammation of s-JIA.