Fluorine-18 Fluorodeoxyglucose Positron Emission Research Articles

Multimodal imaging with (18)F-FDG-PET/CT and (111)In-Octreotide SPECT in patients with metastatic medullary thyroid carcinoma.

The aim of our study was to determine the role of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) and indium-111 Octreotide single photon emission tomography ((111)In-Octreotide SPECT) in the evaluation of metastatic medullary thyroid carcinoma (MMTC). Twenty-five MMTC patients were retrospectively evaluated. All patients had undergone whole-body (18)F-FDG-PET/CT including 20 who had also undergone (111)In-Octreotide SPECT within a maximum interval of 6 weeks. Diagnostic contrast-enhanced computed tomography (CT) alone or as part of (18)F-FDG-PET/CT examination was performed in all patients. Contrast-enhanced CT detected a total of 131 lesions including 79 enlarged lymph nodes and 14 bone lesions. (18)F-FDG-PET/CT visualized a total of 92 true positive lesions (SUVmax range 1.1-10.0, mean 4.0 ± 1.7) including 66 lymph nodes, 7 of which were not enlarged on CT, and 8 bone metastases. In the 20 patients studied with both techniques, a total of 64 and 46 true positive lesions were detected by (18)F-FDG-PET/CT and (111)In-Octreotide SPECT, respectively. In particular, (18)F-FDG uptake was found in 43 lymph nodes and in 7 bone metastases whereas (111)In-Octreotide uptake was detected in 27 lymph nodes and in 10 bone metastases. In MMTC patients, (18)F-FDG-PET/CT provides a useful contribution mainly in evaluating lymph node involvement whereas (111)In-Octreotide SPECT can contribute to the detection and somatostatin receptor characterization especially of bone lesions.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography evaluation of subcutaneous panniculitis-like T cell lymphoma and treatment response

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a very rare variant of non-Hodgkin’s lymphoma. Currently, there is no standard imaging method for staging of SPTCL nor for assessment of treatment response. Here, we describe our use of fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging and monitoring of treatment response in 3 cases of SPTCL. Primary staging by PET/CT showed that all 3 patients had multiple foci in the subcutaneous fat tissue, with SUVmax from 10.5 to 14.6. Involvement of intra-abdominal fat with high SUVmax was identified in 2 of the patients. Use of the triple drug regimen of gemcitabine, cisplatin and methylprednisolone (commonly known as “GEM-P”) as first-line therapy or second-line therapy facilitated complete metabolic response for all 3 cases. FDG PET/CT provides valuable information for staging and monitoring of treatment response and can reveal occult involvement of the intra-abdominal visceral fat. High FDG uptake on pre-treatment PET can identify patients with aggressive disease and help in selection of first-line therapy.

Intraosseous malignant peripheral nerve sheath tumor of distal femur detected with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging

Malignant peripheral nerve sheath tumor (MPNST) is a malignant soft tissue tumor arising from peripheral nerve sheath cells. MPNST is uncommon and can be associated with neurofibromatosis Type I (NF-I). MPNST involving bone is very rare, and we report the case of MPNST involving the distal femur in a patient without NF-I. A 17-year-old boy presented with a history of left knee joint pain and X-ray showed lytic lesion in the distal part of left femur. He was referred for fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to find out the extent of disease. PET/CT showed intense FDG uptake in the lobulated well-defined lesion in the medial part of left distal femur. He underwent biopsy from the lesion which confirmed MPNST.

Great cervical venous tumoral thrombosis of melanotic medullary carcinoma thyroid: Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography enabled diagnosis and radiotherapy planning

The authors report an extremely rare occurrence of a massive tumor thrombus involving right internal and external jugular veins extending into superior vena cava from a still rarer melanotic medullary carcinoma thyroid in the postoperative follow-up. The case was managed by hypofractionated intensity modulated radiotherapy technique with gratifying results.

Unilateral primary adrenal natural killer/T-cell lymphoma: Role of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography for staging and interim response assessment

Primary adrenal lymphoma (PAL) is a rare malignancy often involving bilateral adrenal glands. Diffuse large B-cell is the most common histological type. Unilateral presentation and T-cell/natural killer (T/NK) cell histological type is rarer. We report fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan findings in a case of unilateral T/NK cell PAL performed for staging and interim treatment response assessment.

Active subcutaneous calcinosis demonstrated by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in a case of limited cutaneous systemic sclerosis.

Systemic sclerosis (SSc) is a rheumatic autoimmune disease of unknown origin causing fibrosis of the skin and the internal organs. The limited cutaneous variant is the most common subtype of SSc, and it is predominantly characterized by skin and soft-tissues involvement. A 72-year-old woman, who had been diagnosed with the limited cutaneous form of SSc 16 years before, underwent fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) examination due to unexplained weight loss and recent onset of fatigue and joint pain. PET/CT images showed widespread soft-tissue calcinosis characterized by elevated glucose uptake.

Image findings of rare case of gestational breast cancer diagnosed in a lactating women with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

Gestational or pregnancy-associated breast cancer is defined as breast cancer that is diagnosed during pregnancy, in the first postpartum year, or any time during lactation. We report rare imaging findings of a breast cancer seen on fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) study in a 32-year-old lactating woman. The FDG PET/CT study demonstrated uptake in the soft tissue lesion noted in the right breast corresponding to primary lesion and multiple nodes in bilateral axilla, right supraclavicular and mediastinum. In addition, there was FDG tracer uptake in both the breast parenchyma-related to breast feeding. This case illustrates the first case of breast cancer in a lactating woman detected by FDG PET/CT.

The incidence of 18F-FDG PET/CT thyroid incidentalomas andthe prevalence of malignancy: a prospective study.

To determine the prevalence of malignancy in thyroid incidentalomas (TIs) detected by fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). 18F-FDG PET/CT images were evaluated prospectively for the presence of thyroid uptake. The patients with a TI were evaluated by an endocrinologist according to the predefined diagnostic algorithm. The final diagnosis was obtained clinically and/or by pathology. TI was detected in 4.2% of 4204 patients. A malignant thyroid nodule was diagnosed in 29% and 33% of the focal and diffuse-focal uptake groups, respectively. However, no malignancy was detected in the diffuse uptake group. The standardized maximum uptake values (SUVmax) of the nodules were significantly higher in patients with thyroid malignancy than in patients with benign nodules (P = 0.006). The calculated cut-off value of SUVmax for malignancy was 3.5. In 2 patients in whom the cytopathological diagnosis was benign, malignancy was diagnosed after total thyroidectomy. A malignant nodule was present in one-third of the patients with focal or diffuse-focal uptake. A SUVmax value of 3.5 was considered as a cut-off value for the differentiation of a malignant lesion. Benign cytology in fine-needle aspiration biopsy for 2 patients underestimated a thyroid malignancy.

Role of Pre-therapeutic (18)F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma.

Objective(s):The present study aimed to evaluate the role of pre-therapeutic 18fluorine-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients.Methods:The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative 18F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted 18F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan–Meier product-limit method.Results:In a total of 40 patients, 18F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the 18F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of 18F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant.Conclusion:18F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre-treatment SUVmax failed to stablish its usefulness in the assessment of patient prognosis and survival outcome.

Prognostic impact of initial maximum standardized uptake value of 18F-FDG PET/CT on treatment response in patients with metastatic lung adenocarcinoma treated with erlotinib

PurposeTo investigate whether the initial maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has a prognostic significance in metastatic lung adenocarcinoma.Patients and methodsSixty patients (24 females, mean age: 57.9±12 years) with metastatic stage lung adenocarcinoma who used erlotinib and underwent 18F-FDG PET/CT at the time of diagnosis between May 2010 and May 2014 were enrolled in this retrospective study. The patients were stratified according to the median SUVmax value, which was found as 11. Progression-free survival (PFS) rates for 3, 6, and 12 months were examined for SUVmax values and epidermal growth factor receptor (EGFR) mutation status.ResultsThe number of EGFR-sensitizing mutation positive/negative/unknown was 26/17/17, respectively, and the number of patients using erlotinib at first-line, second-line, and third-line therapy was 15, 31, and 14 consecutively. The PFS rates of EGFR mutation positive, negative, and unknown patients for 3 months were 73.1%, 35.3%, and 41.2% (P=0.026, odds ratio [OR]=4.39; 95% confidence interval [CI]: 1.45–13.26), respectively. The PFS rates of EGFR positive, negative, and unknown patients for 6 months were 50%, 29.4%, and 29.4% (P=0.267, OR: 2.4; 95% CI: 0.82–6.96), respectively. The PFS rates of EGFR positive, negative, and unknown patients for 12 months were 42.3%, 29.4%, 23.5% (P=0.408, OR: 2.0; 95% CI: 0.42–5.26), respectively. Thirty-one of 60 patients had SUVmax values ≤11. The PFS rates for 3, 6, and 12 months were 70.5%/28% (P=0.001, OR=9.0; 95% CI: 2.79–29.04), 61.7%/8% (P<0.001, OR=28.35; 95% CI: 5.5–143), and 52.9%/8% (P<0.001, OR=18.69; 95% CI: 3.76–92.9) for low SUVmax (≤11) group/high SUVmax (>11) group, respectively.ConclusionInitial SUVmax value on 18F-FDG PET/CT is found to be a prognostic factor anticipating the response to erlotinib for 3, 6, and 12-month rates of PFS in both EGFR-sensitizing mutation and wild-type tumor group.

Secondary neurolymphomatosis of spinal nerve roots detected by ¹⁸F-FDG PET/CT: a case report and differential diagnosis of the case.

Neurolymphomatosis (NL) is a rare neurological manifestation of lymphoma. Clinical symptoms of NL differ greatly according to the sites involved and diagnosis with conventional imaging techniques may sometimes be difficult. We herein describe the case of a 58 years old man presenting as radiculopathy with a history of non-Hodgkin's lymphoma (NHL). Computed tomography (CT) was unrevealing and magnetic resonance imaging (MRI) was contraindicated. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was performed and revealed multiple hypermetabolic lesions along the nerve roots, which corresponded to the patient's neurological symptoms. A differential diagnosis of patients with lymphomatous involvement of spinal nerve roots has been presented. Our case suggests that ¹⁸F-FDG PET/CT successfully detected the infiltration of spinal nerve roots of NL due to lymphoma.

Tubular adenoma of the common bile duct with uptake in 18F-FDG PET: A case report.

A 64-year-old man presented with epigastric discomfort and nausea. Laboratory analyses revealed increased levels of total and direct bilirubin, and increased levels of aminotransferases. Computed tomography revealed the presence of a mass in the distal common bile duct. Endoscopic retrograde cholangiopancreatography and intraductal ultrasonography revealed a 25 mm filling defect in the distal common bile duct, and biopsy of the lesion disclosed the presence of tubular adenoma. Using fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) revealed an increased accumulation of the tracer in the lesion, with a maximum standard uptake value (SUVmax) of 3.3. The patient received a pylorus-preserving pancreatoduodenectomy. The histopathological examination revealed a tubular adenoma with low-grade atypia. The patient remains alive 15 months following the surgery, with no evidence of recurrence of the adenoma. 18F-FDG PET has been successfully applied in clinical practice to detect a wide variety of tumor types, including lymphoma, lung, colon and bile duct cancer. In the present study, a case of bile duct adenoma with low-grade atypia was reported, revealing the uptake of 18F-FDG. 18F-FDG PET may be able to detect premalignant tumors of the bile duct, although whether 18F-FDG PET is able to differentially discriminate between diagnoses of adenoma and carcinoma of the bile duct remains to be fully elucidated, and the assessment of further case studies is required.

Takayasu arteritis and antiphospholipid antibody syndrome in an elderly woman

Takayasu arteritis and antiphospholipid antibody syndrome in an elderly woman

Clinicopathologic Features and Molecular Characteristics of Glucose Metabolism Contributing to ¹⁸F-fluorodeoxyglucose Uptake in Gastrointestinal Stromal Tumors.

Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography–computed tomography (PET/CT) is useful in the preoperative diagnosis of gastrointestinal stromal tumors (GISTs); however, the molecular characteristics of glucose metabolism of GIST are unknown. We evaluated 18F-FDG uptake on preoperative PET/CT of 40 patients and analyzed the expression of glycolytic enzymes in resected GIST tissues by qRT-PCR, western blotting, and immunohistochemistry. Results of receiver operating characteristic curve analysis showed that the maximum standardized uptake value (SUVmax) cut-off value of 4.99 had a sensitivity of 89.5%, specificity was 76.2%, and accuracy of 82.5% for identifying tumors with a high risk of malignancy. We found that 18F-FDG uptake correlated positively with tumor size, risk grade, and expression levels of glucose transporter 1 (GLUT1), hexokinase 1 (HK1), and lactate dehydrogenase A (LDHA). Elevated HK and LDH activity was found in high-risk tumors. Among the isoforms of GLUT and HK, GLUT1 and HK1 expression increased with higher tumor risk grade. In addition, overexpression of glycolytic enzymes M2 isoform of pyruvate kinase (PKM2) and LDHA was observed in GISTs, especially in high-risk tumors. These results suggest that upregulation of GLUT1, HK1, PKM2, and LDHA may play an important role in GIST tumorigenesis and may be useful in the preoperative prediction of malignant potential.

Contributory Role of Fluorine 18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis and Clinical Management of Infections in Patients Supported With a Continuous-Flow Left Ventricular Assist Device

The current study sought to demonstrate the advantages offered by fluorine 18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in patients supported with continuous-flow left ventricular assist devices (CF-LVADs) in detecting infection and the consequent effect on clinical decisions. Between April 2009 and September 2013, 40 PET examinations were performed in 31 patients (78.1% men; mean age, 51.0 ± 14.9 years) supported with a CF-LVAD. In group A (19 examinations in 14 patients), PET/CT was performed to detect infectious focus in patients without external signs of driveline involvement but with at least two of the following infection signs: recurrent fever, positive blood culture, or elevated infectious indicators. In group B (21 examinations in 17 patients), PET/CT aimed to assess the internal extension of infection in patients with external signs of driveline infection. In 50% of the cases of the patients in group A, abnormal (18)F-FDG uptake (9 patients) was related to VAD components. Matching the results with the final diagnosis, we reported 9 true-positive, 8 true-negative, no false-negative, and 2 false-positive findings. New information unrelated to VAD was found in 9 patients (50%): pneumonia in 3, colon diverticulitis in 3, sternal dehiscence in 1, paravertebral abscess in 1, and erysipelas in 1. In group B, superficial abnormal (18)F-FDG uptake was found at the piercing site of the driveline in 2 patients, deeper extension of infection along the driveline in 10, initial involvement of the pump housing in 2, and full involvement of the device in 4. These findings contributed to changing the clinical management in 84.2% of group A patients and in 85.7% of group B patients: 16 patients were scheduled for urgent transplantation, 2 underwent surgical revision of the driveline, 7 required prolonged antibiotic therapy, and 3 underwent colonoscopy. This single-center experience highlights the diagnostic value of PET/CT in detecting the localization and internal extension of infection to internal VAD components. Moreover, this information notably influences the therapeutic management.

Frontal metabolic activity contributes to individual differences in vulnerability toward total sleep deprivation-induced changes in cognitive function.

Substantial individual differences characterize the changes induced by total sleep deprivation on cognitive functions. Despite some progress having been achieved, the mechanisms of individual differences in response to total sleep deprivation have not been clearly elucidated. Cerebral metabolism in the resting state is among the key physiological processes supporting the daily function of the brain, and may play an important role in these individual differences. Twenty-two right-handed participants (nine females and 13 males) between 20 and 26years old completed a mathematical processing task both in resting wakefulness and after 24h of total sleep deprivation. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography was used to investigate brain metabolism changes. The mathematical task was performed after the positron emission tomography scans were completed. Correlation analysis was used to investigate the correlations between cognitive performance changes and brain metabolism changes. Large inter-individual differences were found in the throughput changes, but these inter-individual differences were not associated with baseline or post-deprivation performance levels. Specifically, deterioration of throughput on the mathematical processing task was significantly correlated with metabolism changes in the superior frontal medial gyrus. These findings suggested that frontal metabolic activity contributes to individual differences in waking-induced impairment of cognitive performance.

PET/CT Imaging for Monitoring Recurrence and Evaluating Response to Treatment in Breast Cancer

Monitoring recurrence and evaluating response to therapy are important aspects of clinical decision making in the treatment of breast cancer. In this literature review, the authors highlight several of the key areas where integrated fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) measurements are anticipated to have a significant impact on monitoring recurrence and evaluating response to therapy. These areas include comparing FDG PET/CT with conventional imaging for detecting breast cancer metastases; evaluating the role of FDG PET/CT in the presence of elevated tumor markers during follow-up period after the primary surgery; using FDG PET/CT to assess response to neoadjuvant chemotherapy (NAC), targeted and endocrine therapies; using FDG PET/CT to predict response to NAC according to different molecular phenotypes of breast cancer; and applying PET/CT and some new breast-related PET tracers to evaluate response to anticancer treatment. The authors consider the relative advantages afforded by PET/CT and summarize current evidence as to the likely value of PET/CT in recurrence detection and anticancer treatment response prediction.

F-18 FDG uptake on positron emission tomography as a predictor for lymphovascular invasion in patients with lung adenocarcinoma.

To evaluate the contributory value of Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) in the prediction of lymphovascular tumor invasion in patients with lung adenocarcinoma. We evaluated F-18 FDG-PET/CT images in 84 patients with histopathologically proven lung adenocarcinoma (37 men and 47 women, age range 39-83 years, mean age 67.0 ± 8.9 years). The maximum standardized uptake values (SUVmax) of the carcinomas were measured from the PET images. The Mann-Whitney U test was conducted to compare the median SUVmax between the tumor groups with and without lymphovascular invasion. In the subgroup patients with no lymph-node metastasis, we also compared the median SUVmax between the tumor groups with and without lymphatic invasion. The tumors with lymphovascular invasion had a significantly (P < 0.0001) greater median SUVmax than those without invasion. In the subgroup patients with no lymph-node metastasis, the median SUVmax was higher in tumors with lymphatic invasion than those without (P = 0.0004). The sensitivity, specificity, and area under the receiver operating characteristic curve for the detection of tumors with lymphovascular invasion were 89, 75 %, and 0.82, respectively, with a cutoff SUVmax value of 2.32. The SUVmax of lung adenocarcinoma is a potential imaging biomarker for predicting tumor lymphovascular invasion.

Association between serum tumor markers and metabolic tumor volume or total lesion glycolysis in patients with recurrent small cell lung cancer.

The aim of the present study was to investigate the association between serum tumor markers and the metabolic tumor volume (MTV) or total lesion glycolysis (TLG), as determined by fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) in patients with recurrent small cell lung cancer (SCLC). Data from 21 patients with recurrent SCLC were collected. The levels of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and cytokeratin 19 fragment 21-1 were measured at the time of the 18F-FDG PET/CT examination. The MTV and TLG of all lesions were calculated. Pearson correlation analyses were used to estimate the correlations between NSE level and PET findings. Pearson correlation analyses showed that NSE was the only tumor marker to have a strong correlation with MTV or TLG (r=0.787, P<0.001; r=0.866, P<0.001, respectively). In patients with a normal NSE level, no correlation was found between NSE and MTV or TLG (r=0.018, P=0.958; r=-0.003, P=0.92, respectively), but a significant correlation was found in patients with an abnormal NSE level (r=0.789, P<0.01; r=0.872, P=0.01, respectively). Therefore, TLG and MTV may serve as sensitive markers of tumor burden in patients with recurrent SCLC, with TLG showing greater sensitivity. In patients with an abnormal NSE level, a higher NSE level indicates greater MTV and TLG.

Imaging for Staging and Response Assessment in Lymphoma.

Lymphoma comprises a heterogeneous group of diseases; remarkable advances have been made in diagnosis and treatment. Diagnostic imaging provides important information for staging and response assessment in patients with lymphoma. Over the years, staging systems have been refined, and dedicated criteria have been developed for evaluating response to therapy with both computed tomography (CT) and fluorine-18 fluorodeoxyglucose positron emission tomography (PET)/CT. The most recent system proposed for staging and response assessment, known as the Lugano classification, applies to both Hodgkin and non-Hodgkin lymphoma. The use of standardized criteria for staging and response assessment is important for making accurate treatment decisions and for determining the direction of further research. This review provides an overview of the updated CT and PET response criteria to familiarize the radiologist with the most important and clinically relevant aspects of lymphoma imaging. It also provides a short clinical update on lymphoma and the associated spectrum of imaging findings.