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

Primary undifferentiated carcinoma of the small intestine: an immunohistochemical study and review of the literature

Primary undifferentiated carcinoma of the small intestine is an extremely rare neoplasm. Here, we report a case of primary undifferentiated carcinoma that arose from the ileum in a 65-year-old woman. Laboratory data revealed anemia and slightly elevated inflammatory parameters. Computed tomography showed a heterogeneous mass in the pelvic cavity, and magnetic resonance imaging revealed that the margin of the tumor mass was clear. Positron emission tomography using (18)F-fluoro-2-deoxy-D: -glucose (FDG) showed accumulation of FDG on the tumor mass with a standardized uptake value of 8.3. Partial resection of the ileum to remove the tumor was performed under a clinical diagnosis of small intestinal carcinoma. The tumor was nodulated and had a circumscribed margin 6.5 x 5.5 x 4 cm in diameter. Microscopically, the tumor was composed of giant polygonal cells with cellular atypia. Immunohistochemical examination revealed that the tumor cells expressed epithelial markers including AE1/AE3, CAM5.2, and EMA; however, lymphocytic, mesenchymal, and gastrointestinal stromal tumor markers were not expressed. We made a final diagnosis of primary undifferentiated carcinoma of the small intestine. The prognosis of patients with undifferentiated carcinoma of the small intestine is very poor. To improve the outcome of treatment, early and accurate diagnosis is essential, and additional therapy, including multimodality adjuvant therapy or the administration of novel molecular targeted drugs, should be considered.

Assessment of histological response of paediatric bone sarcomas using FDG PET in comparison to morphological volume measurement and standardized MRI parameters

The objective of this study was to evaluate positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI) parameters for the assessment of histological response in paediatric bone sarcoma patients. FDG PET and local MRI were performed in 27 paediatric sarcoma patients [Ewing sarcoma family of tumours (EWS), n = 16; osteosarcoma (OS), n = 11] prior to and after neoadjuvant chemotherapy before local tumour resection. Several parameters for assessment of response of the primary tumour to therapy by FDG PET and MRI were evaluated and compared with histopathological regression of the resected tumour as defined by Salzer-Kuntschik. FDG PET significantly discriminated responders from non-responders using the standardized uptake value (SUV) reduction and the absolute post-therapeutic SUV (SUV2) in the entire patient population (SUV, p = 0.005; SUV2, p = 0.011) as well as in the subgroup of OS patients (SUV, p = 0.009; SUV2, p = 0.028), but not in the EWS subgroup. The volume reduction measured by MRI/CT did not significantly discriminate responders from non-responders either in the entire population (p = 0.170) or in both subgroups (EWS, p = 0.950; OS, p = 1.000). The other MRI parameters alone or in combination were unreliable and did not improve the results. Comparing diagnostic parameters of FDG PET and local MRI, metabolic imaging showed high superiority in the subgroup of OS patients, while similar results were observed in the population of EWS. FDG PET appears to be a useful tool for non-invasive response assessment in the group of OS patients and is superior to MRI. In EWS patients, however, neither FDG PET nor volumetry or standardized MRI criteria enabled a reliable response assessment to be made after neoadjuvant treatment.

Utility of positron emission tomography for tumour surveillance in children with neurofibromatosis type 1

There is little consensus regarding optimal surveillance of optic pathway glioma (OPG) and plexiform neurofibroma (PNF) in childhood neurofibromatosis type 1 (NF1). (18)F-2-Fluoro-2-deoxy-D: -glucose (FDG) positron emission tomography and computed tomography (PET/CT) is employed in the surveillance of adult PNFs; but its utility has neither been specifically studied in children with PNFs nor in children with OPG. Review of PET/CT studies was performed in NF1 children with OPG or PNF. FDG-avidity of tumours was semi-quantitatively analysed and graded by calculating the maximum standardised uptake value (SUV(max)) [grade 1: <3 (low), grade 2: >3-<4 (intermediate), grade 3: >4 (intense)]. Eighteen children (ten girls; median age: 8.5-years) had PET/CT. Nineteen OPGs were imaged. The SUV(max) could be measured in 16. Ten were grade 1 and three each were grade 2 and grade 3. FDG-avidity reduced from grade 3 to grade 1 in two symptomatic OPGs following chemotherapy and this was associated with clinical improvement. PET/CT diagnosed symptomatic OPGs with a sensitivity of 0.625 [95% confidence interval (CI): 0.259-0.897] and specificity of 0.875 (95% CI: 0.466-0.993). Sixteen PNFs were imaged. Twelve were grade 1 and two each were grade 2 and grade 3. The two grade 3 PNFs were confirmed malignant peripheral nerve sheath tumours. PET/CT diagnosed malignant transformation with a sensitivity of 1.0 (95% CI: 0.197-1.0) and specificity of 0.857 (95% CI: 0.561-0.974). PET/CT may contribute useful information to the surveillance of OPG in childhood NF1-particularly to identify progressive, symptomatic tumours. As in adults, PET/CT is useful for the detection of malignant transformation in PNFs in children with NF1.

Multi-Center Study on Alzheimer's Disease Using FDG PET: Group and Individual Analyses

Using statistical parametric mapping (SPM), we evaluate the feasibility and accuracy of (18) F -2-deoxy-2-fluoro-D-glucose (FDG) positron emission tomography (PET) for clinical diagnosis with characteristic hypo-metabolic regions, and examine the consistency of cerebral hypo-metabolism in Alzheimer's disease (AD) cross multicenters at both the group and the individual levels. Four groups of scan data including 39 AD patients and 52 healthy control subjects derived from three centers were analyzed and comparisons between patient subgroups or individual patient and relevant control population were performed using Two Sample T-test. In the group analysis, the hypo-metabolic regions of AD patients obtained from different PET centers were similar and consistent. The common hypo-metabolic cerebral areas were located bilaterally in the posterior cingulate and medial parietal cortex, temporo-parietal cortex, prefrontal cortex, and the middle and inferior temporal gyrus (uncorrected, p<0.001). In the analysis of each individual subject, the location of declined posterior cingulate and medial parietal cortex, temporo-parietal cortex and temporal lobe were found highly consistent with relevant characteristic regions obtained in the group analysis and were selected for diagnostic purposes. Complete typical hypo-metabolic pattern was observed in 67% and 54% of AD patients in two sets of 3D scans, respectively. Only 27% and 33.3% patients showed full typical pattern in two sets of 2D scans. The results indicated that FDG PET measures and SPM can 4 provide a valuable reference for clinical diagnosis of AD patients. The potential influence of acquisition mode on the clinical diagnosis of AD was suggested for further evaluation.

Clinical applications of positron emission tomography-computed tomography in oncology

Positron emission computed tomography (PET) is a functional diagnostic imaging technique, which can accurately measure in vivo distribution of a variety of radiopharmaceuticals. The ability of PET to study various biological processes (glucose, amino acid, phospholipids, receptors etc.) opens up new possibilities for both day-to-day clinical use and research applications in the practice of oncology. Addition of CT to PET has resulted in better specificity and sensitivity than either of the modalities alone, as the combined approach has the ability to demonstrate functional and structural details in the same setting. F-18 fluoro-2-deoxy-D-glucose (FDG), an analogue of glucose, is the most commonly used radiotracer in PET-CT imaging. The F-18 FDG uptake in tumor cells is directly proportional to glucose metabolism in the cells. Since glucose metabolism is increased several folds in the malignant tumors, PET-CT images show preferential higher FDG uptake in malignant cells as compared to normal cells. F-18 FDG PET-CT has been found to be useful in the initial staging, detection of recurrent disease and monitoring the response to the therapy in malignancies including lung cancer, colorectal cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer, breast cancer.

POSITRON EMISSION TOMOGRAPHY - COMPUTERTOMOGRAPHY FUSION IMAGE, WITH 18-FLUORO-2-DEOXYD-GLUCOSE IN THE FOLLOW-UP OF PATIENTS WITHDIFFERENTIATED THYROID CARCINOMA

Aim. The aim of this study is to present the personal experience of the authors regarding the use of positron emission tomography-computer tomography fusion image (PET/CT), with 18 Ffluoro-2-deoxy-D-glucose (FDG), in the follow-up of differentiated thyroid carcinoma (DTC). Patients and Methods. Twenty seven cases of DTC admitted and treated in the “Prof. Ion Chiricuþa” Institute of Oncology Cluj-Napoca (IOCN), performed PET/CT investigation between 2007 and 2009, in DOTE Centre Debrecen (Hungary) and Pozitron Center Oradea (Romania). The patients underwent the surgical intervention and had histology of differentiated carcinoma; they received radioiodine therapy with I-131, had suppression therapy with thyroid hormones and had in the follow-up whole body scans (WBS) with I-131, neck ultrasound and serological determination of thyroglobulin (Tg) and anti-thyroglobulin antibodies (anti-Tg). All patients were referred to PET/CT after radical treatment, after a negative WBS I-131 and a dynamic increase of the serological level of Tg or anti-Tg, without any clinical signs of recurrence and no neck ultrasound pathological findings. Results. All patients included in this study presented abnormal levels of Tg: between 2.76 ng/ml and 4173 ng/ml, with a median value of 43.15 ng/ml. In 23 cases (85.1%) the PET/CT results revealed the neoplasm recurrence, in 3 cases we obtained true negative results and in 1 case a false negative image; in 2 cases (7.4%) we found a second malignancy. All patients needed to change the treatment strategies. Conclusion. The significant increase of the number of DTC and the more aggressive behaviour of the disease in some situations, determines the existence of a clear strategy of treatment and monitoring, where the role of PET/CT is well defined.

PET/CT Appearance of Intestinal Behcet Disease

Behcet disease is a multisystem, chronic relapsing vasculitis of unknown etiology. Gastrointestinal involvement occurs in 10% to 40%, usually affecting the terminal ileum and cecum. Radiologic appearances resemble inflammatory and neoplastic diseases, with differential diagnoses including: Crohn disease, carcinoma, lymphoma, typhlitis, tuberculosis, and amebiasis. While computed tomography (CT) and magnetic resonance imaging appearances have been described, the F-18 fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT appearance of intestinal Behcet disease has not been previously reported. FDG-PET, coregistered with CT, was useful in this case to aid lesion detection, and for determining the extent of disease for treatment planning. The case also highlights the need for awareness of this condition as a rare benign cause for false-positive diagnosis in the assessment for malignancy, with potential avoidance of unnecessary surgery.

Can calcification predict 131I accumulation on metastatic lymph nodes in papillary thyroid carcinoma patients receiving 131I therapy? Comparison of CT, 131I WBS and 18F-FDG PET/CT

The aim of this study was to clarify the predictive significance of nodal calcification in terms of the therapeutic option of (131)I therapy in papillary thyroid carcinoma (PTC) patients. We reviewed 19 computed tomography (CT) examinations of PTC patients on receiving (131)I therapy for the presence of nodal calcification, and compared the (131)I whole-body scintigraphy and (18)F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT findings. The metastatic lymph nodes (mLNs) were divided into three groups: A, those with calcification; B, those without calcification but belonging to patients who had calcified mLNs; C, those without calcification and belonging to patients who had no calcified mLNs. The incidences of (131)I accumulation and maximum standardised uptake values (SUV max) in the three groups were compared. A total of 70 mLNs were evaluated. Twelve mLNs belonged to group A, 13 to group B and 45 to group C. The incidences of (131)I accumulation were significantly higher in groups A (100%) and B (100%) than in group C (11.1%) (p < 0.0001 for both). The SUVmax was significantly lower in groups A (4.1 +/- 1.9) and B (3.9 +/- 1.4) than in group C (7.1 +/- 4.4) (p = 0.01, p = 0.002, respectively). Our results indicated that calcification in mLNs related to the ability of (131)I accumulation and less dedifferentiation.

Widespread Metastases in Small Cell Carcinoma of the Prostate on FDG PET/CT

A 72-year-old man recently diagnosed with a small cell carcinoma of the prostate was referred for staging of the primary malignancy. F-18-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) revealed extensive hypermetabolic metastatic involvement of the liver, multiple small metastatic nodules in the lungs, and a solitary bone metastasis to the left scapula, in addition to increased FDG uptake in the enlarged prostate. Serum prostate-specific antigen level was within normal limits. Although FDG PET is not a helpful imaging method for evaluating prostatic adenocarcinoma, it may be useful in staging of small cell carcinoma of the prostate.

Breast Angiosarcoma

Abstract: Primary and secondary angiosarcoma of the breast is a rare aggressive disease with a poor prognosis. Radiographic features of breast angiosarcoma on mammography, ultrasound and MRI have been studied but F-18 fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) findings have not been described. We present illustrations of FDG PET/CT findings of primary and secondary breast angiosarcoma, respectively. In both cases, intense FDG activity was demonstrated within the primary tumor as well as metastatic disease. FDG PET/CT imaging findings may be useful in initial staging and restaging patients with angiosarcomas. Follow-up studies can be used to document therapeutic response by showing interval resolution of FDG activity.

A Comparison between Radiolabeled Fluorodeoxyglucose Uptake and Hyperpolarized 13C-Labeled Pyruvate Utilization as Methods for Detecting Tumor Response to Treatment

Detection of early tumor responses to treatment can give an indication of clinical outcome. Positron emission tomography measurements of the uptake of the glucose analog, [(18)F] 2-fluoro-2-deoxy-D-glucose (FDG), have demonstrated their potential for detecting early treatment response in the clinic. We have shown recently that (13)C magnetic resonance spectroscopy and spectroscopic imaging measurements of the uptake and conversion of hyperpolarized [1-(13)C]pyruvate into [1-(13)C]lactate can be used to detect treatment response in a murine lymphoma model. The present study compares these magnetic resonance measurements with changes in FDG uptake after chemotherapy. A decrease in FDG uptake was found to precede the decrease in flux of hyperpolarized (13)C label between pyruvate and lactate, both in tumor cells in vitro and in tumors in vivo. However, the magnitude of the decrease in FDG uptake and the decrease in pyruvate to lactate flux was comparable at 24 hours after drug treatment. In cells, the decrease in FDG uptake was shown to correlate with changes in plasma membrane expression of the facilitative glucose transporters, whereas the decrease in pyruvate to lactate flux could be explained by an increase in poly(ADP-ribose) polymerase activity and subsequent depletion of the NAD(H) pool. These results show that measurement of flux between pyruvate and lactate may be an alternative to FDG-positron emission tomography for imaging tumor treatment response in the clinic.

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.

Variability and reproducibility of hepatic FDG uptake measured as SUV as well as tissue‐to‐blood background ratio using positron emission tomography in healthy humans

To investigate variability and reproducibility of hepatic [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) uptake in healthy individuals. Static images were obtained 70 min after the injection of 160 MBq FDG in six healthy subjects at two occasions with 13 days' interval. FDG uptake was adjusted for tissue-to-blood background ratio (T/B), or measured as standardized uptake value (SUV). Small regions of interest (ROIs) of 10 cm(3) in two different hepatic regions were analysed as well as the total liver. Mean SUV was 1.16 +/- 0.15 and mean T/B corrected values was 1.87 +/- 0.17. The maximal values were 2.70 (SUV) and 4.67 (T/B). Reproducibility was 6.7% for the mean SUV and 0.2% for the max SUV values. The corresponding figures for the T/B corrected mean values were 6.4% and for the max T/B values 13.0%. In general, the small ROIs had a comparable or even lower CV% for SUV values, but a higher CV% for T/B corrected values. In normal subjects hepatic FDG-uptake is high and homogeneous with a low CV% between days. T/B corrected values are largely comparable to SUV values but not superior, probably due to the standardization of procedures and homogeneity of the subjects. The T/B corrected method is theoretically superior in a more inhomogeneous population or when using different scanners and is shown here to be easy to apply. Small ROIs of 10 cm(3) are representative with respect to mean FDG uptake in the total liver and reproducibility, but do not identify the max FDG uptake.

Comparative study of FDG PET/CT and conventional imaging in the staging of rhabdomyosarcoma

The current study was conducted to compare the diagnostic accuracy between (18)F-fluoro-2-deoxy-D: -glucose (FDG) positron emission tomography (PET)/computed tomography (CT), and conventional imaging (CI) for the staging and re-staging of patients with rhabdomyosarcomas. Thirty-five patients who underwent FDG PET/CT prior to treatment were evaluated retrospectively. CI methods consisted of (99m)Tc-hydroxymethylene diphosphonate bone scintigraphy, chest radiograph, whole body CT, and magnetic resonance imaging of the primary site. The images were reviewed and two boardcertified radiologists reached a diagnostic consensus. Tumor stage was confirmed by histological examination and/or follow-up examinations. Interpretation on the basis of FDG PET/CT, and CI, diagnostic accuracies of the T and N stages were similar. Using FDG PET/CT, the M stage was correctly assigned in 31 patients (89%), whereas the accuracy of CI in M stage was 63%. TNM stage was correctly assessed with FDG PET/CT in 30 of 35 patients (86%) and with CI in 19 of 35 patients (54%). The overall TNM staging and M staging accuracies of FDG PET/CT were significantly higher than that of CI (P < 0.01). FDG PET/CT is more accurate than CI regarding clinical staging and re-staging of patients with rhabdomyosarcomas.

Prospective evaluation of CECT and 18F-FDG-PET/CT in detection of hepatic metastases

The purpose of this study was to evaluate the performance of F-fluorodeoxy-D-glucose (FDG)-PET/computed tomography (CT) and contrast-enhanced CT (CECT) in the detection and characterization of hepatic metastases. Forty-five patients harboring an extrahepatic primary malignancy, with suspected hepatic metastases on clinical or ultrasonographic examination were enroled prospectively. Each patient underwent contrast-enhanced abdominal CT and F-FDG-PET/CT within 72 h of each other, reported by an experienced radiologist and nuclear medicine specialist, respectively in a blinded manner. CECT and PET-CT findings were compared and analyzed. Final diagnosis was based on histology and/or follow-up (ranging from 6 to 12 months). The sensitivity and specificity of CECT in the detection of hepatic metastases was 87.9 and 16.7%, respectively, whereas that of PET/CT was 97 and 75%, respectively. This study showed the superiority of PET/CT over CECT in the detection of hepatic metastases, irrespective of the primary site. This was especially owing to the latter's inability to reliably distinguish small (less than 15 mm) lesions as benign or malignant. Many studies have been conducted on the impact of FDG-PET/CT in the evaluation of hepatic metastases, especially from colorectal primary. Very few prospective studies, however, have been conducted on its role in evaluation of hepatic metastases from nongastrointestinal primaries. Despite its superior performance, it cannot replace CECT for this purpose, owing to the low but definite risk of false positivity based on PET-CT findings alone. Inclusion of CECT in PET/CT protocols may enable us to achieve a higher diagnostic accuracy. This suggests the need for a large prospective study with serial evaluations and pathological correlation.

Neurosyphilitic gumma on F18-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography: An old disease investigated with a new technology

Neurosyphilitic gumma is a slowly progressive inflammatory manifestation of tertiary syphilis. It is characterised by chronic granulomata that ranges from microscopic lesions to large tumour-like masses. While cutaneous, mucosal and skeletal gummatous lesions are not uncommon, neurosyphilitic gumma is rare. F18-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) has been used effectively to assess the metabolic nature of brain masses, in particular in guiding biopsy and grading gliomas. However, the inflammatory nature of lesions such as neurosyphilitic gumma poses challenges to diagnostic imaging modalities including CT scans, MRI and PET. Since FDG is not a specific tracer for malignancy, neurosyphilitic gumma can mimic a high-grade glioma by demonstrating intense FDG uptake and is therefore a potential diagnostic pitfall. We report a case of neurosyphilitic gumma identified on FDG PET.

Accuracy of whole-body FDG-PET/CT for detecting brain metastases from non-central nervous system tumors

Positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D -glucose (FDG) has a limitation in detecting cerebral metastases; however, the feasibility of detection by inline PET/computed tomography (CT) system remains unknown. We evaluated the accuracy of FDG-PET/CT of body imaging protocol for the detection of cerebral metastases when compared with PET alone and CT alone. Fifty patients underwent whole-body FDG-PET/CT scanning including the brain and contrast enhanced brain MR (magnetic resonance) scan. PET-only, CT-only, and the fused images were interpreted, and the confidence of presence of cerebral metastases was recorded using a five-point grading scale. Area under the receiver-operating characteristic (ROC) curve (Az) was calculated. Differences among the three modalities were tested with the Cochran-Q test, followed by multiple comparisons using the McNemar test with Bonferroni adjustment. Magnetic resonance imaging revealed 70 cerebral metastatic lesions in 20 patients. Patient-based analysis showed that the sensitivity, specificity, accuracy, and Az of PET-alone interpretation were 45%, 80%, 66%, and 0.6025, respectively, those of CT-alone interpretation were 50%, 97%, 78%, and 0.7158, respectively, and those of fused-image interpretation were 50%, 93%, 76%, and 0.7242, respectively. ROC analysis revealed significant differences among the three interpretation methods (P = 0.0238) and between PET and PET/CT (P = 0.0129). The sensitivity of PET, CT, and fused-image interpretation for detecting 70 lesions was 13%, 20%, and 20%, respectively. Even with an integrated PET/CT scanner of body imaging protocol, the sensitivity of cerebral metastases remained unsatisfactory. To assess intracranial lesions, MR scanning should still be considered.

FDG PET/CT findings in acute adult mononucleosis mimicking malignant lymphoma

We report a case of acute Epstein-Barr virus (EBV) infection in which the clinical syndrome and pattern of F-18-2-fluoro-2-deoxy-D-glucose (FDG) uptake mimicked malignant lymphoma. A 53-yr-old man presented with 2 wk of high fevers, night sweats, sinus congestion and severe fatigue. The patient was treated for 1 wk with broad-spectrum antibiotics for acute sinusitis without any improvement. Persistence of fevers and presence of abnormal lymphadenopathy seen on the abdominal computed tomography (CT) were concerning lymphoma with B symptoms. FDG positron emission tomography (PET) showed avid FDG uptake in numerous abdominal/pelvic nodes, liver, spleen and bone marrow. These findings were highly suspicious for lymphoma. Patient underwent a pelvic lymph node biopsy which showed large granular lymphocytes that were predominantly T cells. Bone marrow biopsy showed diffuse infiltration with plasmocytoid cells that were not kappa lambda restricted. Additional diagnostic workup became available showing positive EBV IgM titers and negative IgG levels indicating acute infectious mononucleosis. Lymph node biopsy stained positively with EBV-encoded RNA. We concluded that patient's abnormal FDG PET was most likely secondary to acute EBV infection. After 2 months, follow-up FDG PET/CT showed marked improvement in lymphadenopathy and decreased hypermetabolic activity in the liver and spleen. Other than EBV, there are many other FDG-avid non-malignant conditions that may lead to false-positive PET scans. FDG accumulates in inflamed and infected lesions with increased glucose metabolism. This case underscores the importance of maintaining a broad differential and restricting use of PET scans for staging.

FDG-PET imaging for the evaluation of antiglioma agents in a rat model

The increasing development of novel anticancer agents demands parallel advances in the methods used to rapidly assess their therapeutic efficacy (TE) in the preclinical phase. We evaluated the ability of small-animal PET, using the (18)F-fluoro-deoxy-D-glucose (FDG) radiotracer, to predict the TE of a number of anticancer agents in the rat C6 glioma model following 3 days of treatment. Semi-quantitative measurements of changes in FDG uptake during the course of treatment (standardized uptake value response [SUV(r)]) were found to be significantly lower in tumors treated with the hypoxia-inducible factor-1alpha inhibitor YC-1 (15 mg/kg) than in tumors in the control group. No significant SUV(r) change was observed following a similar 3-day regimen with the proapoptotic agent NS1619 (20 microg/kg), the combination of YC-1 and NS1619, or the alkylating agent temozolomide (7.5 mg/kg). Quantitative immunohistochemical studies demonstrated significantly lower levels of glucose transporter-1 (GLUT-1) expression in the YC-1-treated tumors, thereby correlating with the low SUV(r) observed in this group. The ability of SUV(r) to predict gold-standard outcomes of TE was further validated as YC-1-treated tumors had decreased volumes compared to control tumors. As such, we successfully demonstrated the ability of FDG-PET to rapidly determine the TE of novel agents for the treatment of glioma in the preclinical phase of evaluation.

The value of F-18 FDG-PET/CT in diagnosis of chronic empyema-associated malignancy

Chronic empyema-associated malignancies (CEAM) are rare complications of long-standing empyema. Many tumour types have been described as CEAM, e.g., lymphoma (the most common), squamous cell carcinoma, mesothelioma, various sarcomas, and rarely adenocarcinoma.1–4 Although the plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI) findings of CEAM have been described,1,4 the F-18 fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/CT imaging findings of CEAM at initial diagnosis have not been reported previously.